netlink: let core handle error cases in dump operations

After commit b5a899154aa9 ("netlink: handle EMSGSIZE errors
in the core"), we can remove some code that was not 100 % correct
anyway.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240306102426.245689-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: provide RCU protection to rtnl_fill_prop_list()

We want to be able to run rtnl_fill_ifinfo() under RCU protection
instead of RTNL in the future.

dev->name_node items are already rcu protected.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: make rtnl_fill_link_ifmap() RCU ready

Use READ_ONCE() to read the following device fields:

dev->mem_start
dev->mem_end
dev->base_addr
dev->irq
dev->dma
dev->if_port

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: add RTNL_FLAG_DUMP_UNLOCKED flag

Similarly to RTNL_FLAG_DOIT_UNLOCKED, this new flag
allows dump operations registered via rtnl_register()
or rtnl_register_module() to opt-out from RTNL protection.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: prepare nla_put_iflink() to run under RCU

We want to be able to run rtnl_fill_ifinfo() under RCU protection
instead of RTNL in the future.

This patch prepares dev_get_iflink() and nla_put_iflink()
to run either with RTNL or RCU held.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: remove dev_base_lock from do_setlink()

We hold RTNL here, and dev->link_mode readers already
are using READ_ONCE().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add netdev_set_operstate() helper

dev_base_lock is going away, add netdev_set_operstate() helper
so that hsr does not have to know core internals.

Remove dev_base_lock acquisition from rfc2863_policy()

v3: use an "unsigned int" for dev->operstate,
so that try_cmpxchg() can work on all arches.
( https://lore.kernel.org/oe-kbuild-all/202402081918.OLyGaea3-lkp@intel.com/ )

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net-sysfs: convert dev->operstate reads to lockless ones

operstate_show() can omit dev_base_lock acquisition only
to read dev->operstate.

Annotate accesses to dev->operstate.

Writers still acquire dev_base_lock for mutual exclusion.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

dev: annotate accesses to dev->link

Following patch will read dev->link locklessly,
annotate the write from do_setlink().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: use xarray iterator to implement rtnl_dump_ifinfo()

Adopt net->dev_by_index as I did in commit 0e0939c0adf9
("net-procfs: use xarray iterator to implement /proc/net/dev")

This makes sure an existing device is always visible in the dump,
regardless of concurrent insertions/deletions.

v2: added suggestions from Jakub Kicinski and Ido Schimmel,
thanks for the help !

Link: https://lore.kernel.org/all/20240209142441.6c56435b@kernel.org/
Link: https://lore.kernel.org/all/ZckR-XOsULLI9EHc@shredder/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20240211214404.1882191-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: make dev_unreg_count global

We can use a global dev_unreg_count counter instead
of a per netns one.

As a bonus we can factorize the changes done on it
for bulk device removals.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

dpll: move all dpll<>netdev helpers to dpll code

Older versions of GCC really want to know the full definition
of the type involved in rcu_assign_pointer().

struct dpll_pin is defined in a local header, net/core can't
reach it. Move all the netdev <> dpll code into dpll, where
the type is known. Otherwise we'd need multiple function calls
to jump between the compilation units.

This is the same problem the commit under fixes was trying to address,
but with rcu_assign_pointer() not rcu_dereference().

Some of the exports are not needed, networking core can't
be a module, we only need exports for the helpers used by
drivers.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/all/35a869c8-52e8-177-1d4d-e57578b99b6@linux-m68k.org/
Fixes: 640f41ed33b5 ("dpll: fix build failure due to rcu_dereference_check() on unknown type")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240305013532.694866-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: fix error logic of IFLA_BRIDGE_FLAGS writing back

In the commit d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks
IFLA_BRIDGE_MODE length"), an adjustment was made to the old loop logic
in the function `rtnl_bridge_setlink` to enable the loop to also check
the length of the IFLA_BRIDGE_MODE attribute. However, this adjustment
removed the `break` statement and led to an error logic of the flags
writing back at the end of this function.

if (have_flags)
memcpy(nla_data(attr), &flags, sizeof(flags));
// attr should point to IFLA_BRIDGE_FLAGS NLA !!!

Before the mentioned commit, the `attr` is granted to be IFLA_BRIDGE_FLAGS.
However, this is not necessarily true fow now as the updated loop will let
the attr point to the last NLA, even an invalid NLA which could cause
overflow writes.

This patch introduces a new variable `br_flag` to save the NLA pointer
that points to IFLA_BRIDGE_FLAGS and uses it to resolve the mentioned
error logic.

Fixes: d73ef2d69c0d ("rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20240227121128.608110-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: add rcu safety to rtnl_prop_list_size()

rtnl_prop_list_size() can be called while alternative names
are added or removed concurrently.

if_nlmsg_size() / rtnl_calcit() can indeed be called
without RTNL held.

Use explicit RCU protection to avoid UAF.

Fixes: 88f4fb0c7496 ("net: rtnetlink: put alternative names to getlink message")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240209181248.96637-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Revert "net: rtnetlink: Enslave device before bringing it up"

This reverts commit a4abfa627c3865c37e036bccb681619a50d3d93c.

The patch broke:
> ip link set dummy0 up
> ip link set dummy0 master bond0 down

This last command is useful to be able to enslave an interface with only
one netlink message.

After discussion, there is no good reason to support:
> ip link set dummy0 down
> ip link set dummy0 master bond0 up
because the bond interface already set the slave up when it is up.

Cc: stable@vger.kernel.org
Fixes: a4abfa627c38 ("net: rtnetlink: Enslave device before bringing it up")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240108094103.2001224-2-nicolas.dichtel@6wind.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: bridge: Enable MDB bulk deletion

Now that both the common code as well as individual drivers support MDB
bulk deletion, allow user space to make such requests.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: bridge: Invoke MDB bulk deletion when needed

Invoke the new MDB bulk deletion device operation when the 'NLM_F_BULK'
flag is set in the netlink message header.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: bridge: Use a different policy for MDB bulk delete

For MDB bulk delete we will need to validate 'MDBA_SET_ENTRY'
differently compared to regular delete. Specifically, allow the ifindex
to be zero (in case not filtering on bridge port) and force the address
to be zero as bulk delete based on address is not supported.

Do that by introducing a new policy and choosing the correct policy
based on the presence of the 'NLM_F_BULK' flag in the netlink message
header. Use nlmsg_parse() for strict validation.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnl: use rcu_replace_pointer_rtnl in rtnl_unregister_*

With the introduction of the rcu_replace_pointer_rtnl helper,
cleanup the rtnl_unregister_* functions to use the helper instead
of open coding it.

Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: synchronize link-watch when carrier is queried

There are multiple ways to query for the carrier state: through
rtnetlink, sysfs, and (possibly) ethtool. Synchronize linkwatch
work before these operations so that we don't have a situation
where userspace queries the carrier state between the driver's
carrier off->on transition and linkwatch running and expects it
to work, when really (at least) TX cannot work until linkwatch
has run.

I previously posted a longer explanation of how this applies to
wireless [1] but with this wireless can simply query the state
before sending data, to ensure the kernel is ready for it.

[1] https://lore.kernel.org/all/346b21d87c69f817ea3c37caceb34f1f56255884.camel@sipsolutions.net/

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20231204214706.303c62768415.I1caedccae72ee5a45c9085c5eb49c145ce1c0dd5@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: introduce nlmsg_new_large and use it in rtnl_getlink

if a PF has 256 or more VFs, ip link command will allocate an order 3
memory or more, and maybe trigger OOM due to memory fragment,
the VFs needed memory size is computed in rtnl_vfinfo_size.

so introduce nlmsg_new_large which calls netlink_alloc_large_skb in
which vmalloc is used for large memory, to avoid the failure of
allocating memory

ip invoked oom-killer: gfp_mask=0xc2cc0(GFP_KERNEL|__GFP_NOWARN|\
__GFP_COMP|__GFP_NOMEMALLOC), order=3, oom_score_adj=0
CPU: 74 PID: 204414 Comm: ip Kdump: loaded Tainted: P OE
Call Trace:
dump_stack+0x57/0x6a
dump_header+0x4a/0x210
oom_kill_process+0xe4/0x140
out_of_memory+0x3e8/0x790
__alloc_pages_slowpath.constprop.116+0x953/0xc50
__alloc_pages_nodemask+0x2af/0x310
kmalloc_large_node+0x38/0xf0
__kmalloc_node_track_caller+0x417/0x4d0
__kmalloc_reserve.isra.61+0x2e/0x80
__alloc_skb+0x82/0x1c0
rtnl_getlink+0x24f/0x370
rtnetlink_rcv_msg+0x12c/0x350
netlink_rcv_skb+0x50/0x100
netlink_unicast+0x1b2/0x280
netlink_sendmsg+0x355/0x4a0
sock_sendmsg+0x5b/0x60
____sys_sendmsg+0x1ea/0x250
___sys_sendmsg+0x88/0xd0
__sys_sendmsg+0x5e/0xa0
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f95a65a5b70

Cc: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Link: https://lore.kernel.org/r/20231115120108.3711-1-lirongqing@baidu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: Add MDB get support

Now that both the bridge and VXLAN drivers implement the MDB get net
device operation, expose the functionality to user space by registering
a handler for RTM_GETMDB messages. Derive the net device from the
ifindex specified in the ancillary header and invoke its MDB get NDO.

Note that unlike other get handlers, the allocation of the skb
containing the response is not performed in the common rtnetlink code as
the size is variable and needs to be determined by the respective
driver.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Handle bulk delete policy in bridge driver

The merge commit 92716869375b ("Merge branch 'br-flush-filtering'")
added support for FDB flushing in bridge driver. The following patches
will extend VXLAN driver to support FDB flushing as well. The netlink
message for bulk delete is shared between the drivers. With the existing
implementation, there is no way to prevent user from flushing with
attributes that are not supported per driver. For example, when VNI will
be added, user will not get an error for flush FDB entries in bridge
with VNI, although this attribute is not relevant for bridge.

As preparation for support of FDB flush in VXLAN driver, move the policy
to be handled in bridge driver, later a new policy for VXLAN will be
added in VXLAN driver. Do not pass 'vid' as part of ndo_fdb_del_bulk(),
as this field is relevant only for bridge.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netdev: expose DPLL pin handle for netdevice

In case netdevice represents a SyncE port, the user needs to understand
the connection between netdevice and associated DPLL pin. There might me
multiple netdevices pointing to the same pin, in case of VF/SF
implementation.

Add a IFLA Netlink attribute to nest the DPLL pin handle, similar to
how it is implemented for devlink port. Add a struct dpll_pin pointer
to netdev and protect access to it by RTNL. Expose netdev_dpll_pin_set()
and netdev_dpll_pin_clear() helpers to the drivers so they can set/clear
the DPLL pin relationship to netdev.

Note that during the lifetime of struct dpll_pin the pin handle does not
change. Therefore it is save to access it lockless. It is drivers
responsibility to call netdev_dpll_pin_clear() before dpll_pin_put().

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: Correct offload_xstats size

rtnl_offload_xstats_get_size_hw_s_info_one() conditionalizes the
size-computation for IFLA_OFFLOAD_XSTATS_HW_S_INFO_USED based on whether
or not the device has offload_xstats enabled.

However, rtnl_offload_xstats_fill_hw_s_info_one() is adding the u8 for
that field uncondtionally.

syzkaller triggered a WARNING in rtnl_stats_get due to this:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 754 at net/core/rtnetlink.c:5982 rtnl_stats_get+0x2f4/0x300
Modules linked in:
CPU: 0 PID: 754 Comm: syz-executor148 Not tainted 6.6.0-rc2-g331b78eb12af #45
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
RIP: 0010:rtnl_stats_get+0x2f4/0x300 net/core/rtnetlink.c:5982
Code: ff ff 89 ee e8 7d 72 50 ff 83 fd a6 74 17 e8 33 6e 50 ff 4c 89 ef be 02 00 00 00 e8 86 00 fa ff e9 7b fe ff ff e8 1c 6e 50 ff <0f> 0b eb e5 e8 73 79 7b 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900006837c0 EFLAGS: 00010293
RAX: ffffffff81cf7f24 RBX: ffff8881015d9000 RCX: ffff888101815a00
RDX: 0000000000000000 RSI: 00000000ffffffa6 RDI: 00000000ffffffa6
RBP: 00000000ffffffa6 R08: ffffffff81cf7f03 R09: 0000000000000001
R10: ffff888101ba47b9 R11: ffff888101815a00 R12: ffff8881017dae00
R13: ffff8881017dad00 R14: ffffc90000683ab8 R15: ffffffff83c1f740
FS: 00007fbc22dbc740(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000046 CR3: 000000010264e003 CR4: 0000000000170ef0
Call Trace:
<TASK>
rtnetlink_rcv_msg+0x677/0x710 net/core/rtnetlink.c:6480
netlink_rcv_skb+0xea/0x1c0 net/netlink/af_netlink.c:2545
netlink_unicast+0x430/0x500 net/netlink/af_netlink.c:1342
netlink_sendmsg+0x4fc/0x620 net/netlink/af_netlink.c:1910
sock_sendmsg+0xa8/0xd0 net/socket.c:730
____sys_sendmsg+0x22a/0x320 net/socket.c:2541
___sys_sendmsg+0x143/0x190 net/socket.c:2595
__x64_sys_sendmsg+0xd8/0x150 net/socket.c:2624
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x47/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7fbc22e8d6a9
Code: 5c c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 4f 37 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007ffc4320e778 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004007d0 RCX: 00007fbc22e8d6a9
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 00000000004007d0
R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffc4320e898
R13: 00007ffc4320e8a8 R14: 00000000004004a0 R15: 00007fbc22fa5a80
</TASK>
---[ end trace 0000000000000000 ]---

Which didn't happen prior to commit bf9f1baa279f ("net: add dedicated
kmem_cache for typical/small skb->head") as the skb always was large
enough.

Fixes: 0e7788fd7622 ("net: rtnetlink: Add UAPI for obtaining L3 offload xstats")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/20231013041448.8229-1-cpaasch@apple.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bridge: Add backup nexthop ID support

Add a new bridge port attribute that allows attaching a nexthop object
ID to an skb that is redirected to a backup bridge port with VLAN
tunneling enabled.

Specifically, when redirecting a known unicast packet, read the backup
nexthop ID from the bridge port that lost its carrier and set it in the
bridge control block of the skb before forwarding it via the backup
port. Note that reading the ID from the bridge port should not result in
a cache miss as the ID is added next to the 'backup_port' field that was
already accessed. After this change, the 'state' field still stays on
the first cache line, together with other data path related fields such
as 'flags and 'vlgrp':

struct net_bridge_port {
struct net_bridge * br; /* 0 8 */
struct net_device * dev; /* 8 8 */
netdevice_tracker dev_tracker; /* 16 0 */
struct list_head list; /* 16 16 */
long unsigned int flags; /* 32 8 */
struct net_bridge_vlan_group * vlgrp; /* 40 8 */
struct net_bridge_port * backup_port; /* 48 8 */
u32 backup_nhid; /* 56 4 */
u8 priority; /* 60 1 */
u8 state; /* 61 1 */
u16 port_no; /* 62 2 */
/* --- cacheline 1 boundary (64 bytes) --- */
[...]
} __attribute__((__aligned__(8)));

When forwarding an skb via a bridge port that has VLAN tunneling
enabled, check if the backup nexthop ID stored in the bridge control
block is valid (i.e., not zero). If so, instead of attaching the
pre-allocated metadata (that only has the tunnel key set), allocate a
new metadata, set both the tunnel key and the nexthop object ID and
attach it to the skb.

By default, do not dump the new attribute to user space as a value of
zero is an invalid nexthop object ID.

The above is useful for EVPN multihoming. When one of the links
composing an Ethernet Segment (ES) fails, traffic needs to be redirected
towards the host via one of the other ES peers. For example, if a host
is multihomed to three different VTEPs, the backup port of each ES link
needs to be set to the VXLAN device and the backup nexthop ID needs to
point to an FDB nexthop group that includes the IP addresses of the
other two VTEPs. The VXLAN driver will extract the ID from the metadata
of the redirected skb, calculate its flow hash and forward it towards
one of the other VTEPs. If the ID does not exist, or represents an
invalid nexthop object, the VXLAN driver will drop the skb. This
relieves the bridge driver from the need to validate the ID.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Move nesting cancellation rollback to proper function

Make rtnl_fill_vf() cancel the vfinfo attribute on error instead of the
inner rtnl_fill_vfinfo(), as it is the function that starts it.

Signed-off-by: Gal Pressman <gal@nvidia.com>
Link: https://lore.kernel.org/r/20230716072440.2372567-1-gal@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

rtnetlink: Reject negative ifindexes in RTM_NEWLINK

Negative ifindexes are illegal, but the kernel does not validate the
ifindex in the ancillary header of RTM_NEWLINK messages, resulting in
the kernel generating a warning [1] when such an ifindex is specified.

Fix by rejecting negative ifindexes.

[1]
WARNING: CPU: 0 PID: 5031 at net/core/dev.c:9593 dev_index_reserve+0x1a2/0x1c0 net/core/dev.c:9593
[...]
Call Trace:
<TASK>
register_netdevice+0x69a/0x1490 net/core/dev.c:10081
br_dev_newlink+0x27/0x110 net/bridge/br_netlink.c:1552
rtnl_newlink_create net/core/rtnetlink.c:3471 [inline]
__rtnl_newlink+0x115e/0x18c0 net/core/rtnetlink.c:3688
rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3701
rtnetlink_rcv_msg+0x439/0xd30 net/core/rtnetlink.c:6427
netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2545
netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
netlink_unicast+0x536/0x810 net/netlink/af_netlink.c:1368
netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910
sock_sendmsg_nosec net/socket.c:728 [inline]
sock_sendmsg+0xd9/0x180 net/socket.c:751
____sys_sendmsg+0x6ac/0x940 net/socket.c:2538
___sys_sendmsg+0x135/0x1d0 net/socket.c:2592
__sys_sendmsg+0x117/0x1e0 net/socket.c:2621
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 38f7b870d4a6 ("[RTNETLINK]: Link creation API")
Reported-by: syzbot+5ba06978f34abb058571@syzkaller.appspotmail.com
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230823064348.2252280-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: validate veth and vxcan peer ifindexes

veth and vxcan need to make sure the ifindexes of the peer
are not negative, core does not validate this.

Using iproute2 with user-space-level checking removed:

Before:

# ./ip link add index 10 type veth peer index -1
# ip link show
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: enp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
link/ether 52:54:00:74:b2:03 brd ff:ff:ff:ff:ff:ff
10: veth1@veth0: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 8a:90:ff:57:6d:5d brd ff:ff:ff:ff:ff:ff
-1: veth0@veth1: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether ae:ed:18:e6:fa:7f brd ff:ff:ff:ff:ff:ff

Now:

$ ./ip link add index 10 type veth peer index -1
Error: ifindex can't be negative.

This problem surfaced in net-next because an explicit WARN()
was added, the root cause is older.

Fixes: e6f8f1a739b6 ("veth: Allow to create peer link with given ifindex")
Fixes: a8f820a380a2 ("can: add Virtual CAN Tunnel driver (vxcan)")
Reported-by: syzbot+5ba06978f34abb058571@syzkaller.appspotmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length

There are totally 9 ndo_bridge_setlink handlers in the current kernel,
which are 1) bnxt_bridge_setlink, 2) be_ndo_bridge_setlink 3)
i40e_ndo_bridge_setlink 4) ice_bridge_setlink 5)
ixgbe_ndo_bridge_setlink 6) mlx5e_bridge_setlink 7)
nfp_net_bridge_setlink 8) qeth_l2_bridge_setlink 9) br_setlink.

By investigating the code, we find that 1-7 parse and use nlattr
IFLA_BRIDGE_MODE but 3 and 4 forget to do the nla_len check. This can
lead to an out-of-attribute read and allow a malformed nlattr (e.g.,
length 0) to be viewed as a 2 byte integer.

To avoid such issues, also for other ndo_bridge_setlink handlers in the
future. This patch adds the nla_len check in rtnl_bridge_setlink and
does an early error return if length mismatches. To make it works, the
break is removed from the parsing for IFLA_BRIDGE_FLAGS to make sure
this nla_for_each_nested iterates every attribute.

Fixes: b1edc14a3fbf ("ice: Implement ice_bridge_getlink and ice_bridge_setlink")
Fixes: 51616018dd1b ("i40e: Add support for getlink, setlink ndo ops")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20230726075314.1059224-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

netlink: do not hard code device address lenth in fdb dumps

syzbot reports that some netdev devices do not have a six bytes
address [1]

Replace ETH_ALEN by dev->addr_len.

[1] (Case of a device where dev->addr_len = 4)

BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in copyout+0xb8/0x100 lib/iov_iter.c:169
instrument_copy_to_user include/linux/instrumented.h:114 [inline]
copyout+0xb8/0x100 lib/iov_iter.c:169
_copy_to_iter+0x6d8/0x1d00 lib/iov_iter.c:536
copy_to_iter include/linux/uio.h:206 [inline]
simple_copy_to_iter+0x68/0xa0 net/core/datagram.c:513
__skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:419
skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:527
skb_copy_datagram_msg include/linux/skbuff.h:3960 [inline]
netlink_recvmsg+0x4ae/0x15a0 net/netlink/af_netlink.c:1970
sock_recvmsg_nosec net/socket.c:1019 [inline]
sock_recvmsg net/socket.c:1040 [inline]
____sys_recvmsg+0x283/0x7f0 net/socket.c:2722
___sys_recvmsg+0x223/0x840 net/socket.c:2764
do_recvmmsg+0x4f9/0xfd0 net/socket.c:2858
__sys_recvmmsg net/socket.c:2937 [inline]
__do_sys_recvmmsg net/socket.c:2960 [inline]
__se_sys_recvmmsg net/socket.c:2953 [inline]
__x64_sys_recvmmsg+0x397/0x490 net/socket.c:2953
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was stored to memory at:
__nla_put lib/nlattr.c:1009 [inline]
nla_put+0x1c6/0x230 lib/nlattr.c:1067
nlmsg_populate_fdb_fill+0x2b8/0x600 net/core/rtnetlink.c:4071
nlmsg_populate_fdb net/core/rtnetlink.c:4418 [inline]
ndo_dflt_fdb_dump+0x616/0x840 net/core/rtnetlink.c:4456
rtnl_fdb_dump+0x14ff/0x1fc0 net/core/rtnetlink.c:4629
netlink_dump+0x9d1/0x1310 net/netlink/af_netlink.c:2268
netlink_recvmsg+0xc5c/0x15a0 net/netlink/af_netlink.c:1995
sock_recvmsg_nosec+0x7a/0x120 net/socket.c:1019
____sys_recvmsg+0x664/0x7f0 net/socket.c:2720
___sys_recvmsg+0x223/0x840 net/socket.c:2764
do_recvmmsg+0x4f9/0xfd0 net/socket.c:2858
__sys_recvmmsg net/socket.c:2937 [inline]
__do_sys_recvmmsg net/socket.c:2960 [inline]
__se_sys_recvmmsg net/socket.c:2953 [inline]
__x64_sys_recvmmsg+0x397/0x490 net/socket.c:2953
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was created at:
slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:716
slab_alloc_node mm/slub.c:3451 [inline]
__kmem_cache_alloc_node+0x4ff/0x8b0 mm/slub.c:3490
kmalloc_trace+0x51/0x200 mm/slab_common.c:1057
kmalloc include/linux/slab.h:559 [inline]
__hw_addr_create net/core/dev_addr_lists.c:60 [inline]
__hw_addr_add_ex+0x2e5/0x9e0 net/core/dev_addr_lists.c:118
__dev_mc_add net/core/dev_addr_lists.c:867 [inline]
dev_mc_add+0x9a/0x130 net/core/dev_addr_lists.c:885
igmp6_group_added+0x267/0xbc0 net/ipv6/mcast.c:680
ipv6_mc_up+0x296/0x3b0 net/ipv6/mcast.c:2754
ipv6_mc_remap+0x1e/0x30 net/ipv6/mcast.c:2708
addrconf_type_change net/ipv6/addrconf.c:3731 [inline]
addrconf_notify+0x4d3/0x1d90 net/ipv6/addrconf.c:3699
notifier_call_chain kernel/notifier.c:93 [inline]
raw_notifier_call_chain+0xe4/0x430 kernel/notifier.c:461
call_netdevice_notifiers_info net/core/dev.c:1935 [inline]
call_netdevice_notifiers_extack net/core/dev.c:1973 [inline]
call_netdevice_notifiers+0x1ee/0x2d0 net/core/dev.c:1987
bond_enslave+0xccd/0x53f0 drivers/net/bonding/bond_main.c:1906
do_set_master net/core/rtnetlink.c:2626 [inline]
rtnl_newlink_create net/core/rtnetlink.c:3460 [inline]
__rtnl_newlink net/core/rtnetlink.c:3660 [inline]
rtnl_newlink+0x378c/0x40e0 net/core/rtnetlink.c:3673
rtnetlink_rcv_msg+0x16a6/0x1840 net/core/rtnetlink.c:6395
netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2546
rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6413
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0xf28/0x1230 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x122f/0x13d0 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x999/0xd50 net/socket.c:2503
___sys_sendmsg+0x28d/0x3c0 net/socket.c:2557
__sys_sendmsg net/socket.c:2586 [inline]
__do_sys_sendmsg net/socket.c:2595 [inline]
__se_sys_sendmsg net/socket.c:2593 [inline]
__x64_sys_sendmsg+0x304/0x490 net/socket.c:2593
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Bytes 2856-2857 of 3500 are uninitialized
Memory access of size 3500 starts at ffff888018d99104
Data copied to user address 0000000020000480

Fixes: d83b06036048 ("net: add fdb generic dump routine")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20230621174720.1845040-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: move validate_linkmsg out of do_setlink

This patch moves validate_linkmsg() out of do_setlink() to its callers
and deletes the early validate_linkmsg() call in __rtnl_newlink(), so
that it will not call validate_linkmsg() twice in either of the paths:

- __rtnl_newlink() -> do_setlink()
- __rtnl_newlink() -> rtnl_newlink_create() -> rtnl_create_link()

Additionally, as validate_linkmsg() is now only called with a real
dev, we can remove the NULL check for dev in validate_linkmsg().

Note that we moved validate_linkmsg() check to the places where it has
not done any changes to the dev, as Jakub suggested.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/cf2ef061e08251faf9e8be25ff0d61150c030475.1686585334.git.lucien.xin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: extend RTEXT_FILTER_SKIP_STATS to IFLA_VF_INFO

This filter already exists for excluding IPv6 SNMP stats. Extend its
definition to also exclude IFLA_VF_INFO stats in RTM_GETLINK.

This patch constitutes a partial fix for a netlink attribute nesting
overflow bug in IFLA_VFINFO_LIST. By excluding the stats when the
requester doesn't need them, the truncation of the VF list is avoided.

While it was technically only the stats added in commit c5a9f6f0ab40
("net/core: Add drop counters to VF statistics") breaking the camel's
back, the appreciable size of the stats data should never have been
included without due consideration for the maximum number of VFs
supported by PCI.

Fixes: 3b766cd83232 ("net/core: Add reading VF statistics through the PF netdevice")
Fixes: c5a9f6f0ab40 ("net/core: Add drop counters to VF statistics")
Signed-off-by: Edwin Peer <edwin.peer@broadcom.com>
Cc: Edwin Peer <espeer@gmail.com>
Signed-off-by: Gal Pressman <gal@nvidia.com>
Link: https://lore.kernel.org/r/20230611105108.122586-1-gal@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

rtnetlink: add the missing IFLA_GRO_ tb check in validate_linkmsg

This fixes the issue that dev gro_max_size and gso_ipv4_max_size
can be set to a huge value:

# ip link add dummy1 type dummy
# ip link set dummy1 gro_max_size 4294967295
# ip -d link show dummy1
dummy addrgenmode eui64 ... gro_max_size 4294967295

Fixes: 0fe79f28bfaf ("net: allow gro_max_size to exceed 65536")
Fixes: 9eefedd58ae1 ("net: add gso_ipv4_max_size and gro_ipv4_max_size per device")
Reported-by: Xiumei Mu <xmu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: move IFLA_GSO_ tb check to validate_linkmsg

These IFLA_GSO_* tb check should also be done for the new created link,
otherwise, they can be set to a huge value when creating links:

# ip link add dummy1 gso_max_size 4294967295 type dummy
# ip -d link show dummy1
dummy addrgenmode eui64 ... gso_max_size 4294967295

Fixes: 46e6b992c250 ("rtnetlink: allow GSO maximums to be set on device creation")
Fixes: 9eefedd58ae1 ("net: add gso_ipv4_max_size and gro_ipv4_max_size per device")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: call validate_linkmsg in rtnl_create_link

validate_linkmsg() was introduced by commit 1840bb13c22f5b ("[RTNL]:
Validate hardware and broadcast address attribute for RTM_NEWLINK")
to validate tb[IFLA_ADDRESS/BROADCAST] for existing links. The same
check should also be done for newly created links.

This patch adds validate_linkmsg() call in rtnl_create_link(), to
avoid the invalid address set when creating some devices like:

# ip link add dummy0 type dummy
# ip link add link dummy0 name mac0 address 01:02 type macsec

Fixes: 0e06877c6fdb ("[RTNETLINK]: rtnl_link: allow specifying initial device address")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bridge: Allow setting per-{Port, VLAN} neighbor suppression state

Add a new bridge port attribute that allows user space to enable
per-{Port, VLAN} neighbor suppression. Example:

# bridge -d -j -p link show dev swp1 | jq '.[]["neigh_vlan_suppress"]'
false
# bridge link set dev swp1 neigh_vlan_suppress on
# bridge -d -j -p link show dev swp1 | jq '.[]["neigh_vlan_suppress"]'
true
# bridge link set dev swp1 neigh_vlan_suppress off
# bridge -d -j -p link show dev swp1 | jq '.[]["neigh_vlan_suppress"]'
false

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dst: Switch to rcuref_t reference counting

Under high contention dst_entry::__refcnt becomes a significant bottleneck.

atomic_inc_not_zero() is implemented with a cmpxchg() loop, which goes into
high retry rates on contention.

Switch the reference count to rcuref_t which results in a significant
performance gain. Rename the reference count member to __rcuref to reflect
the change.

The gain depends on the micro-architecture and the number of concurrent
operations and has been measured in the range of +25% to +130% with a
localhost memtier/memcached benchmark which amplifies the problem
massively.

Running the memtier/memcached benchmark over a real (1Gb) network
connection the conversion on top of the false sharing fix for struct
dst_entry::__refcnt results in a total gain in the 2%-5% range over the
upstream baseline.

Reported-by: Wangyang Guo <wangyang.guo@intel.com>
Reported-by: Arjan Van De Ven <arjan.van.de.ven@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230307125538.989175656@linutronix.de
Link: https://lore.kernel.org/r/20230323102800.215027837@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: bridge: mcast: Relax group address validation in common code

In the upcoming VXLAN MDB implementation, the 0.0.0.0 and :: MDB entries
will act as catchall entries for unregistered IP multicast traffic in a
similar fashion to the 00:00:00:00:00:00 VXLAN FDB entry that is used to
transmit BUM traffic.

In deployments where inter-subnet multicast forwarding is used, not all
the VTEPs in a tenant domain are members in all the broadcast domains.
It is therefore advantageous to transmit BULL (broadcast, unknown
unicast and link-local multicast) and unregistered IP multicast traffic
on different tunnels. If the same tunnel was used, a VTEP only
interested in IP multicast traffic would also pull all the BULL traffic
and drop it as it is not a member in the originating broadcast domain
[1].

Prepare for this change by allowing the 0.0.0.0 group address in the
common rtnetlink MDB code and forbid it in the bridge driver. A similar
change is not needed for IPv6 because the common code only validates
that the group address is not the all-nodes address.

[1] https://datatracker.ietf.org/doc/html/draft-ietf-bess-evpn-irb-mcast#section-2.6

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: bridge: mcast: Move MDB handlers out of bridge driver

Currently, the bridge driver registers handlers for MDB netlink
messages, making it impossible for other drivers to implement MDB
support.

As a preparation for VXLAN MDB support, move the MDB handlers out of the
bridge driver to the core rtnetlink code. The rtnetlink code will call
into individual drivers by invoking their previously added MDB net
device operations.

Note that while the diffstat is large, the change is mechanical. It
moves code out of the bridge driver to rtnetlink code. Also note that a
similar change was made in 2012 with commit 77162022ab26 ("net: add
generic PF_BRIDGE:RTM_ FDB hooks") that moved FDB handlers out of the
bridge driver to the core rtnetlink code.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Restore RTM_NEW/DELLINK notification behavior

The commits referenced below allows userspace to use the NLM_F_ECHO flag
for RTM_NEW/DELLINK operations to receive unicast notifications for the
affected link. Prior to these changes, applications may have relied on
multicast notifications to learn the same information without specifying
the NLM_F_ECHO flag.

For such applications, the mentioned commits changed the behavior for
requests not using NLM_F_ECHO. Multicast notifications are still received,
but now use the portid of the requester and the sequence number of the
request instead of zero values used previously. For the application, this
message may be unexpected and likely handled as a response to the
NLM_F_ACKed request, especially if it uses the same socket to handle
requests and notifications.

To fix existing applications relying on the old notification behavior,
set the portid and sequence number in the notification only if the
request included the NLM_F_ECHO flag. This restores the old behavior
for applications not using it, but allows unicasted notifications for
others.

Fixes: f3a63cce1b4f ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link")
Fixes: d88e136cab37 ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_newlink_create")
Signed-off-by: Martin Willi <martin@strongswan.org>
Acked-by: Guillaume Nault <gnault@redhat.com>
Acked-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20230411074319.24133-1-martin@strongswan.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: bridge: Add netlink knobs for number / maximum MDB entries

The previous patch added accounting for number of MDB entries per port and
per port-VLAN, and the logic to verify that these values stay within
configured bounds. However it didn't provide means to actually configure
those bounds or read the occupancy. This patch does that.

Two new netlink attributes are added for the MDB occupancy:
IFLA_BRPORT_MCAST_N_GROUPS for the per-port occupancy and
BRIDGE_VLANDB_ENTRY_MCAST_N_GROUPS for the per-port-VLAN occupancy.
And another two for the maximum number of MDB entries:
IFLA_BRPORT_MCAST_MAX_GROUPS for the per-port maximum, and
BRIDGE_VLANDB_ENTRY_MCAST_MAX_GROUPS for the per-port-VLAN one.

Note that the two new IFLA_BRPORT_ attributes prompt bumping of
RTNL_SLAVE_MAX_TYPE to size the slave attribute tables large enough.

The new attributes are used like this:

# ip link add name br up type bridge vlan_filtering 1 mcast_snooping 1 \
mcast_vlan_snooping 1 mcast_querier 1
# ip link set dev v1 master br
# bridge vlan add dev v1 vid 2

# bridge vlan set dev v1 vid 1 mcast_max_groups 1
# bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 1
# bridge mdb add dev br port v1 grp 230.1.2.4 temp vid 1
Error: bridge: Port-VLAN is already in 1 groups, and mcast_max_groups=1.

# bridge link set dev v1 mcast_max_groups 1
# bridge mdb add dev br port v1 grp 230.1.2.3 temp vid 2
Error: bridge: Port is already in 1 groups, and mcast_max_groups=1.

# bridge -d link show
5: v1@v2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master br [...]
[...] mcast_n_groups 1 mcast_max_groups 1

# bridge -d vlan show
port vlan-id
br 1 PVID Egress Untagged
state forwarding mcast_router 1
v1 1 PVID Egress Untagged
[...] mcast_n_groups 1 mcast_max_groups 1
2
[...] mcast_n_groups 0 mcast_max_groups 0

Signed-off-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add gso_ipv4_max_size and gro_ipv4_max_size per device

This patch introduces gso_ipv4_max_size and gro_ipv4_max_size
per device and adds netlink attributes for them, so that IPV4
BIG TCP can be guarded by a separate tunable in the next patch.

To not break the old application using "gso/gro_max_size" for
IPv4 GSO packets, this patch updates "gso/gro_ipv4_max_size"
in netif_set_gso/gro_max_size() if the new size isn't greater
than GSO_LEGACY_MAX_SIZE, so that nothing will change even if
userspace doesn't realize the new netlink attributes.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: expose devlink port over rtnetlink

Expose devlink port handle related to netdev over rtnetlink. Introduce a
new nested IFLA attribute to carry the info. Call into devlink code to
fill-up the nest with existing devlink attributes that are used over
devlink netlink.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

bridge: Add MAC Authentication Bypass (MAB) support

Hosts that support 802.1X authentication are able to authenticate
themselves by exchanging EAPOL frames with an authenticator (Ethernet
bridge, in this case) and an authentication server. Access to the
network is only granted by the authenticator to successfully
authenticated hosts.

The above is implemented in the bridge using the "locked" bridge port
option. When enabled, link-local frames (e.g., EAPOL) can be locally
received by the bridge, but all other frames are dropped unless the host
is authenticated. That is, unless the user space control plane installed
an FDB entry according to which the source address of the frame is
located behind the locked ingress port. The entry can be dynamic, in
which case learning needs to be enabled so that the entry will be
refreshed by incoming traffic.

There are deployments in which not all the devices connected to the
authenticator (the bridge) support 802.1X. Such devices can include
printers and cameras. One option to support such deployments is to
unlock the bridge ports connecting these devices, but a slightly more
secure option is to use MAB. When MAB is enabled, the MAC address of the
connected device is used as the user name and password for the
authentication.

For MAB to work, the user space control plane needs to be notified about
MAC addresses that are trying to gain access so that they will be
compared against an allow list. This can be implemented via the regular
learning process with the sole difference that learned FDB entries are
installed with a new "locked" flag indicating that the entry cannot be
used to authenticate the device. The flag cannot be set by user space,
but user space can clear the flag by replacing the entry, thereby
authenticating the device.

Locked FDB entries implement the following semantics with regards to
roaming, aging and forwarding:

1. Roaming: Locked FDB entries can roam to unlocked (authorized) ports,
in which case the "locked" flag is cleared. FDB entries cannot roam
to locked ports regardless of MAB being enabled or not. Therefore,
locked FDB entries are only created if an FDB entry with the given {MAC,
VID} does not already exist. This behavior prevents unauthenticated
devices from disrupting traffic destined to already authenticated
devices.

2. Aging: Locked FDB entries age and refresh by incoming traffic like
regular entries.

3. Forwarding: Locked FDB entries forward traffic like regular entries.
If user space detects an unauthorized MAC behind a locked port and
wishes to prevent traffic with this MAC DA from reaching the host, it
can do so using tc or a different mechanism.

Enable the above behavior using a new bridge port option called "mab".
It can only be enabled on a bridge port that is both locked and has
learning enabled. Locked FDB entries are flushed from the port once MAB
is disabled. A new option is added because there are pure 802.1X
deployments that are not interested in notifications about locked FDB
entries.

Signed-off-by: Hans J. Schultz <netdev@kapio-technology.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link

This patch use the new helper unregister_netdevice_many_notify() for
rtnl_delete_link(), so that the kernel could reply unicast when userspace
set NLM_F_ECHO flag to request the new created interface info.

At the same time, the parameters of rtnl_delete_link() need to be updated
since we need nlmsghdr and portid info.

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: Honour NLM_F_ECHO flag in rtnl_newlink_create

This patch pass the netlink header message in rtnl_newlink_create() to
the new updated rtnl_configure_link(), so that the kernel could reply
unicast when userspace set NLM_F_ECHO flag to request the new created
interface info.

Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: pass netlink message header and portid to rtnl_configure_link()

This patch pass netlink message header and portid to rtnl_configure_link()
All the functions in this call chain need to add the parameters so we can
use them in the last call rtnl_notify(), and notify the userspace about
the new link info if NLM_F_ECHO flag is set.

- rtnl_configure_link()
- __dev_notify_flags()
- rtmsg_ifinfo()
- rtmsg_ifinfo_event()
- rtmsg_ifinfo_build_skb()
- rtmsg_ifinfo_send()
- rtnl_notify()

Also move __dev_notify_flags() declaration to net/core/dev.h, as Jakub
suggested.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: rtnetlink: Enslave device before bringing it up

Unlike with bridges, one can't add an interface to a bond and set it up
at the same time:

| # ip link set dummy0 down
| # ip link set dummy0 master bond0 up
| Error: Device can not be enslaved while up.

Of all drivers with ndo_add_slave callback, bond and team decline if
IFF_UP flag is set, vrf cycles the interface (i.e., sets it down and
immediately up again) and the others just don't care.

Support the common notion of setting the interface up after enslaving it
by sorting the operations accordingly.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220914150623.24152-1-phil@nwl.cc
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: advertise allmulti counter

Like what was done with IFLA_PROMISCUITY, add IFLA_ALLMULTI to advertise
the allmulti counter.
The flag IFF_ALLMULTI is advertised only if it was directly set by a
userland app.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: use netif_oper_up instead of open code

The open code is defined as a new helper function(netif_oper_up) on netdev.h,
the code is dev->operstate == IF_OPER_UP || dev->operstate == IF_OPER_UNKNOWN.
Thus, replace the open code to netif_oper_up. This patch doesn't change logic.

Signed-off-by: Juhee Kang <claudiajkang@gmail.com>
Link: https://lore.kernel.org/r/20220831125845.1333-1-claudiajkang@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: rtnetlink: fix module reference count leak issue in rtnetlink_rcv_msg

When bulk delete command is received in the rtnetlink_rcv_msg function,
if bulk delete is not supported, module_put is not called to release
the reference counting. As a result, module reference count is leaked.

Fixes: a6cec0bcd342 ("net: rtnetlink: add bulk delete support flag")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20220815024629.240367-1-shaozhengchao@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: allow gro_max_size to exceed 65536

Allow the gro_max_size to exceed a value larger than 65536.

There weren't really any external limitations that prevented this other
than the fact that IPv4 only supports a 16 bit length field. Since we have
the option of adding a hop-by-hop header for IPv6 we can allow IPv6 to
exceed this value and for IPv4 and non-TCP flows we can cap things at 65536
via a constant rather than relying on gro_max_size.

[edumazet] limit GRO_MAX_SIZE to (8 * 65535) to avoid overflows.

Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: allow gso_max_size to exceed 65536

The code for gso_max_size was added originally to allow for debugging and
workaround of buggy devices that couldn't support TSO with blocks 64K in
size. The original reason for limiting it to 64K was because that was the
existing limits of IPv4 and non-jumbogram IPv6 length fields.

With the addition of Big TCP we can remove this limit and allow the value
to potentially go up to UINT_MAX and instead be limited by the tso_max_size
value.

So in order to support this we need to go through and clean up the
remaining users of the gso_max_size value so that the values will cap at
64K for non-TCPv6 flows. In addition we can clean up the GSO_MAX_SIZE value
so that 64K becomes GSO_LEGACY_MAX_SIZE and UINT_MAX will now be the upper
limit for GSO_MAX_SIZE.

v6: (edumazet) fixed a compile error if CONFIG_IPV6=n,
in a new sk_trim_gso_size() helper.
netif_set_tso_max_size() caps the requested TSO size
with GSO_MAX_SIZE.

Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add IFLA_TSO_{MAX_SIZE|SEGS} attributes

New netlink attributes IFLA_TSO_MAX_SIZE and IFLA_TSO_MAX_SEGS
are used to report to user-space the device TSO limits.

ip -d link sh dev eth1
...
tso_max_size 65536 tso_max_segs 65535

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: verify rate parameters for calls to ndo_set_vf_rate

When calling ndo_set_vf_rate() the max_tx_rate parameter may be zero,
in which case the setting is cleared, or it must be greater or equal to
min_tx_rate.

Enforce this requirement on all calls to ndo_set_vf_rate via a wrapper
which also only calls ndo_set_vf_rate() if defined by the driver.

Based on work by Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Bin Chen <bin.chen@corigine.com>
Signed-off-by: Baowen Zheng <baowen.zheng@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

rtnetlink: add extack support in fdb del handlers

Add extack support to .ndo_fdb_del in netdevice.h and
all related methods.

Signed-off-by: Alaa Mohamed <eng.alaamohamedsoliman.am@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: don't allow user space to lift the device limits

Up until commit 46e6b992c250 ("rtnetlink: allow GSO maximums to
be set on device creation") the gso_max_segs and gso_max_size
of a device were not controlled from user space.

The quoted commit added the ability to control them because of
the following setup:

netns A | netns B
veth<->veth eth0

If eth0 has TSO limitations and user wants to efficiently forward
traffic between eth0 and the veths they should copy the TSO
limitations of eth0 onto the veths. This would happen automatically
for macvlans or ipvlan but veth users are not so lucky (given the
loose coupling).

Unfortunately the commit in question allowed users to also override
the limits on real HW devices.

It may be useful to control the max GSO size and someone may be using
that ability (not that I know of any user), so create a separate set
of knobs to reliably record the TSO limitations. Validate the user
requests.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnl: move rtnl_newlink_create()

Pure code move.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

rtnl: split __rtnl_newlink() into two functions

__rtnl_newlink() is 250LoC, but has a few clear sections.
Move the part which creates a new netdev to a separate
function.

For ease of review code will be moved in the next change.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

rtnl: allocate more attr tables on the heap

Commit a293974590cf ("rtnetlink: avoid frame size warning in rtnl_newlink()")
moved to allocating the largest attribute array of rtnl_newlink()
on the heap. Kalle reports the stack has grown above 1k again:

net/core/rtnetlink.c:3557:1: error: the frame size of 1104 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

Move more attrs to the heap, wrap them in a struct.
Don't bother with linkinfo, it's referenced a lot and we take
its size so it's awkward to move, plus it's small (6 elements).

Reported-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Tested-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Revert "rtnetlink: return EINVAL when request cannot succeed"

This reverts commit b6177d3240a4

ip-link command is testing kernel capability by sending a RTM_NEWLINK
request, without any argument. It accepts everything in reply, except
EOPNOTSUPP and EINVAL (functions iplink_have_newlink / accept_msg)

So we must keep compatiblity here, invalid empty message should not
return EINVAL

Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Tested-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: return EINVAL when request cannot succeed

A request without interface name/interface index/interface group cannot
work. We should return EINVAL

Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Brian Baboch <brian.baboch@wifirst.fr>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

rtnetlink: return ENODEV when IFLA_ALT_IFNAME is used in dellink

If IFLA_ALT_IFNAME is set and given interface is not found,
we should return ENODEV and be consistent with IFLA_IFNAME
behaviour
This commit extends feature of commit 76c9ac0ee878,
"net: rtnetlink: add possibility to use alternative names as message handle"

CC: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Brian Baboch <brian.baboch@wifirst.fr>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

rtnetlink: enable alt_ifname for setlink/newlink

buffer called "ifname" given in function rtnl_dev_get
is always valid when called by setlink/newlink,
but contains only empty string when IFLA_IFNAME is not given. So
IFLA_ALT_IFNAME is always ignored

This patch fixes rtnl_dev_get function with a remove of ifname argument,
and move ifname copy in do_setlink when required.

It extends feature of commit 76c9ac0ee878,
"net: rtnetlink: add possibility to use alternative names as message
handle""

CC: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Brian Baboch <brian.baboch@wifirst.fr>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

rtnetlink: return ENODEV when ifname does not exist and group is given

When the interface does not exist, and a group is given, the given
parameters are being set to all interfaces of the given group. The given
IFNAME/ALT_IF_NAME are being ignored in that case.

That can be dangerous since a typo (or a deleted interface) can produce
weird side effects for caller:

Case 1:

IFLA_IFNAME=valid_interface
IFLA_GROUP=1
MTU=1234

Case 1 will update MTU and group of the given interface "valid_interface".

Case 2:

IFLA_IFNAME=doesnotexist
IFLA_GROUP=1
MTU=1234

Case 2 will update MTU of all interfaces in group 1. IFLA_IFNAME is
ignored in this case

This behaviour is not consistent and dangerous. In order to fix this issue,
we now return ENODEV when the given IFNAME does not exist.

Signed-off-by: Florent Fourcot <florent.fourcot@wifirst.fr>
Signed-off-by: Brian Baboch <brian.baboch@wifirst.fr>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: rtnetlink: add ndm flags and state mask attributes

Add ndm flags/state masks which will be used for bulk delete filtering.
All of these are used by the bridge and vxlan drivers. Also minimal attr
policy validation is added, it is up to ndo_fdb_del_bulk implementers to
further validate them.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: add NLM_F_BULK support to rtnl_fdb_del

When NLM_F_BULK is specified in a fdb del message we need to handle it
differently. First since this is a new call we can strictly validate the
passed attributes, at first only ifindex and vlan are allowed as these
will be the initially supported filter attributes, any other attribute
is rejected. The mac address is no longer mandatory, but we use it
to error out in older kernels because it cannot be specified with bulk
request (the attribute is not allowed) and then we have to dispatch
the call to ndo_fdb_del_bulk if the device supports it. The del bulk
callback can do further validation of the attributes if necessary.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: add bulk delete support flag

Add a new rtnl flag (RTNL_FLAG_BULK_DEL_SUPPORTED) which is used to
verify that the delete operation allows bulk object deletion. Also emit
a warning if anyone tries to set it for non-delete kind.

Suggested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: add helper to extract msg type's kind

Add a helper which extracts the msg type's kind using the kind mask (0x3).

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: add msg kind names

Add rtnl kind names instead of using raw values. We'll need to
check for DEL kind later to validate bulk flag support.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: extract a few internals from netdevice.h

There's a number of functions and static variables used
under net/core/ but not from the outside. We currently
dump most of them into netdevice.h. That bad for many
reasons:
- netdevice.h is very cluttered, hard to figure out
what the APIs are;
- netdevice.h is very long;
- we have to touch netdevice.h more which causes expensive
incremental builds.

Create a header under net/core/ and move some declarations.

The new header is also a bit of a catch-all but that's
fine, if we create more specific headers people will
likely over-think where their declaration fit best.
And end up putting them in netdevice.h, again.

More work should be done on splitting netdevice.h into more
targeted headers, but that'd be more time consuming so small
steps.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: ensure net_todo_list is processed quickly

In [1], Will raised a potential issue that the cfg80211 code,
which does (from a locking perspective)

rtnl_lock()
wiphy_lock()
rtnl_unlock()

might be suspectible to ABBA deadlocks, because rtnl_unlock()
calls netdev_run_todo(), which might end up calling rtnl_lock()
again, which could then deadlock (see the comment in the code
added here for the scenario).

Some back and forth and thinking ensued, but clearly this can't
happen if the net_todo_list is empty at the rtnl_unlock() here.
Clearly, the code here cannot actually put an entry on it, and
all other users of rtnl_unlock() will empty it since that will
always go through netdev_run_todo(), emptying the list.

So the only other way to get there would be to add to the list
and then unlock the RTNL without going through rtnl_unlock(),
which is only possible through __rtnl_unlock(). However, this
isn't exported and not used in many places, and none of them
seem to be able to unregister before using it.

Therefore, add a WARN_ON() in the code to ensure this invariant
won't be broken, so that the cfg80211 (or any similar) code
stays safe.

[1] https://lore.kernel.org/r/Yjzpo3TfZxtKPMAG@google.com

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20220404113847.0ee02e4a70da.Ic73d206e217db20fd22dcec14fe5442ca732804b@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: Fix handling of disabled L3 stats in RTM_GETSTATS replies

When L3 stats are disabled, rtnl_offload_xstats_get_size_stats() returns
size of 0, which is supposed to be an indication that the corresponding
attribute should not be emitted. However, instead, the current code
reserves a 0-byte attribute.

The reason this does not show up as a citation on a kasan kernel is that
netdev_offload_xstats_get(), which is supposed to fill in the data, never
ends up getting called, because rtnl_offload_xstats_get_stats() notices
that the stats are not actually used and skips the call.

Thus a zero-length IFLA_OFFLOAD_XSTATS_L3_STATS attribute ends up in a
response, confusing the userspace.

Fix by skipping the L3-stats related block in rtnl_offload_xstats_fill().

Fixes: 0e7788fd7622 ("net: rtnetlink: Add UAPI for obtaining L3 offload xstats")
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/591b58e7623edc3eb66dd1fcfa8c8f133d090974.1649794741.git.petrm@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: limit altnames to 64k total

Property list (altname is a link "property") is wrapped
in a nlattr. nlattrs length is 16bit so practically
speaking the list of properties can't be longer than
that, otherwise user space would have to interpret
broken netlink messages.

Prevent the problem from occurring by checking the length
of the property list before adding new entries.

Reported-by: George Shuklin <george.shuklin@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: account alternate interface name memory

George reports that altnames can eat up kernel memory.
We should charge that memory appropriately.

Reported-by: George Shuklin <george.shuklin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: rtnetlink: fix error handling in rtnl_fill_statsinfo()

The clang static analyzer reports this issue
rtnetlink.c:5481:2: warning: Undefined or garbage
value returned to caller
return err;
^~~~~~~~~~

There is a function level err variable, in the
list_for_each_entry_rcu block there is a shadow
err. Remove the shadow.

In the same block, the call to nla_nest_start_noflag()
can fail without setting an err. Set the err
to -EMSGSIZE.

Fixes: 216e690631f5 ("net: rtnetlink: rtnl_fill_statsinfo(): Permit non-EMSGSIZE error returns")
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: Add UAPI toggle for IFLA_OFFLOAD_XSTATS_L3_STATS

The offloaded HW stats are designed to allow per-netdevice enablement and
disablement. Add an attribute, IFLA_STATS_SET_OFFLOAD_XSTATS_L3_STATS,
which should be carried by the RTM_SETSTATS message, and expresses a desire
to toggle L3 offload xstats on or off.

As part of the above, add an exported function rtnl_offload_xstats_notify()
that drivers can use when they have installed or deinstalled the counters
backing the HW stats.

At this point, it is possible to enable, disable and query L3 offload
xstats on netdevices. (However there is no driver actually implementing
these.)

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: Add RTM_SETSTATS

The offloaded HW stats are designed to allow per-netdevice enablement and
disablement. These stats are only accessible through RTM_GETSTATS, and
therefore should be toggled by a RTM_SETSTATS message. Add it, and the
necessary skeleton handler.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: Add UAPI for obtaining L3 offload xstats

Add a new IFLA_STATS_LINK_OFFLOAD_XSTATS child attribute,
IFLA_OFFLOAD_XSTATS_L3_STATS, to carry statistics for traffic that takes
place in a HW router.

The offloaded HW stats are designed to allow per-netdevice enablement and
disablement. Additionally, as a netdevice is configured, it may become or
cease being suitable for binding of a HW counter. Both of these aspects
need to be communicated to the userspace. To that end, add another child
attribute, IFLA_OFFLOAD_XSTATS_HW_S_INFO:

- attr nest IFLA_OFFLOAD_XSTATS_HW_S_INFO
- attr nest IFLA_OFFLOAD_XSTATS_L3_STATS
- attr IFLA_OFFLOAD_XSTATS_HW_S_INFO_REQUEST
- {0,1} as u8
- attr IFLA_OFFLOAD_XSTATS_HW_S_INFO_USED
- {0,1} as u8

Thus this one attribute is a nest that can be used to carry information
about various types of HW statistics, and indexing is very simply done by
wrapping the information for a given statistics suite into the attribute
that carries the suite is the RTM_GETSTATS query. At the same time, because
_HW_S_INFO is nested directly below IFLA_STATS_LINK_OFFLOAD_XSTATS, it is
possible through filtering to request only the metadata about individual
statistics suites, without having to hit the HW to get the actual counters.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: rtnl_fill_statsinfo(): Permit non-EMSGSIZE error returns

Obtaining stats for the IFLA_STATS_LINK_OFFLOAD_XSTATS nest involves a HW
access, and can fail for more reasons than just netlink message size
exhaustion. Therefore do not always return -EMSGSIZE on the failure path,
but respect the error code provided by the callee. Set the error explicitly
where it is reasonable to assume -EMSGSIZE as the failure reason.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: Propagate extack to rtnl_offload_xstats_fill()

Later patches add handlers for more HW-backed statistics. An extack will be
useful when communicating HW / driver errors to the client. Add the
arguments as appropriate.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: RTM_GETSTATS: Allow filtering inside nests

The filter_mask field of RTM_GETSTATS header determines which top-level
attributes should be included in the netlink response. This saves
processing time by only including the bits that the user cares about
instead of always dumping everything. This is doubly important for
HW-backed statistics that would typically require a trip to the device to
fetch the stats.

So far there was only one HW-backed stat suite per attribute. However,
IFLA_STATS_LINK_OFFLOAD_XSTATS is a nest, and will gain a new stat suite in
the following patches. It would therefore be advantageous to be able to
filter within that nest, and select just one or the other HW-backed
statistics suite.

Extend rtnetlink so that RTM_GETSTATS permits attributes in the payload.
The scheme is as follows:

- RTM_GETSTATS
- struct if_stats_msg
- attr nest IFLA_STATS_GET_FILTERS
- attr IFLA_STATS_LINK_OFFLOAD_XSTATS
- u32 filter_mask

This scheme reuses the existing enumerators by nesting them in a dedicated
context attribute. This is covered by policies as usual, therefore a
gradual opt-in is possible. Currently only IFLA_STATS_LINK_OFFLOAD_XSTATS
nest has filtering enabled, because for the SW counters the issue does not
seem to be that important.

rtnl_offload_xstats_get_size() and _fill() are extended to observe the
requested filters.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: Stop assuming that IFLA_OFFLOAD_XSTATS_* are dev-backed

The IFLA_STATS_LINK_OFFLOAD_XSTATS attribute is a nest whose child
attributes carry various special hardware statistics. The code that handles
this nest was written with the idea that all these statistics would be
exposed by the device driver of a physical netdevice.

In the following patches, a new attribute is added to the abovementioned
nest, which however can be defined for some soft netdevices. The NDO-based
approach to querying these does not work, because it is not the soft
netdevice driver that exposes these statistics, but an offloading NIC
driver that does so.

The current code does not scale well to this usage. Simply rewrite it back
to the pattern seen in other fill-like and get_size-like functions
elsewhere.

Extract to helpers the code that is concerned with handling specifically
NDO-backed statistics so that it can be easily reused should more such
statistics be added.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: Namespace functions related to IFLA_OFFLOAD_XSTATS_*

The currently used names rtnl_get_offload_stats() and
rtnl_get_offload_stats_size() do not clearly show the namespace. The former
function additionally seems to have been named this way in accordance with
the NDO name, as opposed to the naming used in the rtnetlink.c file (and
indeed elsewhere in the netlink handling code). As more and
differently-flavored attributes are introduced, a common clear prefix is
needed for all related functions.

Rename the functions to follow the rtnl_offload_xstats_* naming scheme.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: rtnl_stats_get(): Emit an extack for unset filter_mask

Both get and dump handlers for RTM_GETSTATS require that a filter_mask, a
mask of which attributes should be emitted in the netlink response, is
unset. rtnl_stats_dump() does include an extack in the bounce,
rtnl_stats_get() however does not. Fix the omission.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/01feb1f4bbd22a19f6629503c4f366aed6424567.1645020876.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: make net->dev_unreg_count atomic

Having to acquire rtnl from netdev_run_todo() for every dismantled
device is not desirable when/if rtnl is under stress.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net_sched: add __rcu annotation to netdev->qdisc

syzbot found a data-race [1] which lead me to add __rcu
annotations to netdev->qdisc, and proper accessors
to get LOCKDEP support.

[1]
BUG: KCSAN: data-race in dev_activate / qdisc_lookup_rcu

write to 0xffff888168ad6410 of 8 bytes by task 13559 on cpu 1:
attach_default_qdiscs net/sched/sch_generic.c:1167 [inline]
dev_activate+0x2ed/0x8f0 net/sched/sch_generic.c:1221
__dev_open+0x2e9/0x3a0 net/core/dev.c:1416
__dev_change_flags+0x167/0x3f0 net/core/dev.c:8139
rtnl_configure_link+0xc2/0x150 net/core/rtnetlink.c:3150
__rtnl_newlink net/core/rtnetlink.c:3489 [inline]
rtnl_newlink+0xf4d/0x13e0 net/core/rtnetlink.c:3529
rtnetlink_rcv_msg+0x745/0x7e0 net/core/rtnetlink.c:5594
netlink_rcv_skb+0x14e/0x250 net/netlink/af_netlink.c:2494
rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5612
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x602/0x6d0 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x728/0x850 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:705 [inline]
sock_sendmsg net/socket.c:725 [inline]
____sys_sendmsg+0x39a/0x510 net/socket.c:2413
___sys_sendmsg net/socket.c:2467 [inline]
__sys_sendmsg+0x195/0x230 net/socket.c:2496
__do_sys_sendmsg net/socket.c:2505 [inline]
__se_sys_sendmsg net/socket.c:2503 [inline]
__x64_sys_sendmsg+0x42/0x50 net/socket.c:2503
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888168ad6410 of 8 bytes by task 13560 on cpu 0:
qdisc_lookup_rcu+0x30/0x2e0 net/sched/sch_api.c:323
__tcf_qdisc_find+0x74/0x3a0 net/sched/cls_api.c:1050
tc_del_tfilter+0x1c7/0x1350 net/sched/cls_api.c:2211
rtnetlink_rcv_msg+0x5ba/0x7e0 net/core/rtnetlink.c:5585
netlink_rcv_skb+0x14e/0x250 net/netlink/af_netlink.c:2494
rtnetlink_rcv+0x18/0x20 net/core/rtnetlink.c:5612
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x602/0x6d0 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x728/0x850 net/netlink/af_netlink.c:1919
sock_sendmsg_nosec net/socket.c:705 [inline]
sock_sendmsg net/socket.c:725 [inline]
____sys_sendmsg+0x39a/0x510 net/socket.c:2413
___sys_sendmsg net/socket.c:2467 [inline]
__sys_sendmsg+0x195/0x230 net/socket.c:2496
__do_sys_sendmsg net/socket.c:2505 [inline]
__se_sys_sendmsg net/socket.c:2503 [inline]
__x64_sys_sendmsg+0x42/0x50 net/socket.c:2503
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffffffff85dee080 -> 0xffff88815d96ec00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 13560 Comm: syz-executor.2 Not tainted 5.17.0-rc3-syzkaller-00116-gf1baf68e1383-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 470502de5bdb ("net: sched: unlock rules update API")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Vlad Buslov <vladbu@mellanox.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: make sure to refresh master_dev/m_ops in __rtnl_newlink()

While looking at one unrelated syzbot bug, I found the replay logic
in __rtnl_newlink() to potentially trigger use-after-free.

It is better to clear master_dev and m_ops inside the loop,
in case we have to replay it.

Fixes: ba7d49b1f0f8 ("rtnetlink: provide api for getting and setting slave info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20220201012106.216495-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

gro: add ability to control gro max packet size

Eric Dumazet suggested to allow users to modify max GRO packet size.

We have seen GRO being disabled by users of appliances (such as
wifi access points) because of claimed bufferbloat issues,
or some work arounds in sch_cake, to split GRO/GSO packets.

Instead of disabling GRO completely, one can chose to limit
the maximum packet size of GRO packets, depending on their
latency constraints.

This patch adds a per device gro_max_size attribute
that can be changed with ip link command.

ip link set dev eth0 gro_max_size 16000

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Coco Li <lixiaoyan@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Write lock dev_base_lock without disabling bottom halves.

The writer acquires dev_base_lock with disabled bottom halves.
The reader can acquire dev_base_lock without disabling bottom halves
because there is no writer in softirq context.

On PREEMPT_RT the softirqs are preemptible and local_bh_disable() acts
as a lock to ensure that resources, that are protected by disabling
bottom halves, remain protected.
This leads to a circular locking dependency if the lock acquired with
disabled bottom halves (as in write_lock_bh()) and somewhere else with
enabled bottom halves (as by read_lock() in netstat_show()) followed by
disabling bottom halves (cxgb_get_stats() -> t4_wr_mbox_meat_timeout()
-> spin_lock_bh()). This is the reverse locking order.

All read_lock() invocation are from sysfs callback which are not invoked
from softirq context. Therefore there is no need to disable bottom
halves while acquiring a write lock.

Acquire the write lock of dev_base_lock without disabling bottom halves.

Reported-by: Pei Zhang <pezhang@redhat.com>
Reported-by: Luis Claudio R. Goncalves <lgoncalv@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: remove .ndo_change_proto_down

.ndo_change_proto_down was added seemingly to enable out-of-tree
implementations. Over 2.5yrs later we still have no real users
upstream. Hardwire the generic implementation for now, we can
revert once real users materialize. (rocker is a test vehicle,
not a user.)

We need to drop the optimization on the sysfs side, because
unlike ndos priv_flags will be changed at runtime, so we'd
need READ_ONCE/WRITE_ONCE everywhere..

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: annotate accesses to dev->gso_max_segs

dev->gso_max_segs is written under RTNL protection, or when the device is
not yet visible, but is read locklessly.

Add netif_set_gso_max_segs() helper.

Add the READ_ONCE()/WRITE_ONCE() pairs, and use netif_set_gso_max_segs()
where we can to better document what is going on.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: use __dev_addr_set()

Get it ready for constant netdev->dev_addr.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core: Remove unused assignment operations and variable

Although if_info_size is assigned, it has not been used. And the variable
should also be deleted.

The clang_analyzer complains as follows:

net/core/rtnetlink.c:3806: warning:

Although the value stored to 'if_info_size' is used in the enclosing
expression, the value is never actually read from 'if_info_size'.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: luo penghao <luo.penghao@zte.com.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: make use of helper netif_is_bridge_master()

Make use of netdev helper functions to improve code readability.
Replace 'dev->priv_flags & IFF_EBRIDGE' with netif_is_bridge_master(dev).

Signed-off-by: Kyungrok Chung <acadx0@gmail.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: convert rcu_assign_pointer to RCU_INIT_POINTER

It no need barrier when assigning a NULL value to an RCU protected
pointer. So use RCU_INIT_POINTER() instead for more fast.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: fix if_nlmsg_stats_size() under estimation

rtnl_fill_statsinfo() is filling skb with one mandatory if_stats_msg structure.

nlmsg_put(skb, pid, seq, type, sizeof(struct if_stats_msg), flags);

But if_nlmsg_stats_size() never considered the needed storage.

This bug did not show up because alloc_skb(X) allocates skb with
extra tailroom, because of added alignments. This could very well
be changed in the future to have deterministic behavior.

Fixes: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump link stats")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Support filtering interfaces on no master

Currently there's support for filtering neighbours/links for interfaces
which have a specific master device (using the IFLA_MASTER/NDA_MASTER
attributes).

This patch adds support for filtering interfaces/neighbours dump for
interfaces that *don't* have a master.

Signed-off-by: Lahav Schlesinger <lschlesinger@drivenets.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20210810090658.2778960-1-lschlesinger@drivenets.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: add extack arg for link ops

Pass extack arg to validate_linkmsg and validate_link_af callbacks.
If a netlink attribute has a reject_message, use the extended ack
mechanism to carry the message back to user space.

Signed-off-by: Rocco Yue <rocco.yue@mediatek.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: netlink: add the case when nlh is NULL

Add the case when nlh is NULL in nlmsg_report(),
so that the caller doesn't need to deal with this case.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: use nlmsg_notify() in rtnetlink_send()

The netlink_{broadcast, unicast} don't deal with 'if (err > 0' statement
but nlmsg_{multicast, unicast} do. The nlmsg_notify() contains them.
so use nlmsg_notify() instead. so that the caller wouldn't deal with
'if (err > 0' statement.

v2: use nlmsg_notify() will do well.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Return correct error on changing device netns

Currently when device is moved between network namespaces using
RTM_NEWLINK message type and one of netns attributes (FLA_NET_NS_PID,
IFLA_NET_NS_FD, IFLA_TARGET_NETNSID) but w/o specifying IFLA_IFNAME, and
target namespace already has device with same name, userspace will get
EINVAL what is confusing and makes debugging harder.

Fix it so that userspace gets more appropriate EEXIST instead what makes
debugging much easier.

Before:

# ./ifname.sh
+ ip netns add ns0
+ ip netns exec ns0 ip link add l0 type dummy
+ ip netns exec ns0 ip link show l0
8: l0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 66:90:b5:d5:78:69 brd ff:ff:ff:ff:ff:ff
+ ip link add l0 type dummy
+ ip link show l0
10: l0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 6e:c6:1f:15:20:8d brd ff:ff:ff:ff:ff:ff
+ ip link set l0 netns ns0
RTNETLINK answers: Invalid argument

After:

# ./ifname.sh
+ ip netns add ns0
+ ip netns exec ns0 ip link add l0 type dummy
+ ip netns exec ns0 ip link show l0
8: l0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 1e:4a:72:e3:e3:8f brd ff:ff:ff:ff:ff:ff
+ ip link add l0 type dummy
+ ip link show l0
10: l0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether f2:fc:fe:2b:7d:a6 brd ff:ff:ff:ff:ff:ff
+ ip link set l0 netns ns0
RTNETLINK answers: File exists

The problem is that do_setlink() passes its `char *ifname` argument,
that it gets from a caller, to __dev_change_net_namespace() as is (as
`const char *pat`), but semantics of ifname and pat can be different.

For example, __rtnl_newlink() does this:

net/core/rtnetlink.c
3270 char ifname[IFNAMSIZ];
...
3286 if (tb[IFLA_IFNAME])
3287 nla_strscpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
3288 else
3289 ifname[0] = '\0';
...
3364 if (dev) {
...
3394 return do_setlink(skb, dev, ifm, extack, tb, ifname, status);
3395 }

, i.e. do_setlink() gets ifname pointer that is always valid no matter
if user specified IFLA_IFNAME or not and then do_setlink() passes this
ifname pointer as is to __dev_change_net_namespace() as pat argument.

But the pat (pattern) in __dev_change_net_namespace() is used as:

net/core/dev.c
11198 err = -EEXIST;
11199 if (__dev_get_by_name(net, dev->name)) {
11200 /* We get here if we can't use the current device name */
11201 if (!pat)
11202 goto out;
11203 err = dev_get_valid_name(net, dev, pat);
11204 if (err < 0)
11205 goto out;
11206 }

As the result the `goto out` path on line 11202 is neven taken and
instead of returning EEXIST defined on line 11198,
__dev_change_net_namespace() returns an error from dev_get_valid_name()
and this, in turn, will be EINVAL for ifname[0] = '\0' set earlier.

Fixes: d8a5ec672768 ("[NET]: netlink support for moving devices between network namespaces.")
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: say "local" instead of "static" addresses in ndo_dflt_fdb_{add,del}

"Static" is a loaded word, and probably not what the author meant when
the code was written.

In particular, this looks weird:
$ bridge fdb add dev swp0 00:01:02:03:04:05 local # totally fine, but
$ bridge fdb add dev swp0 00:01:02:03:04:05 static
[ 2020.708298] swp0: FDB only supports static addresses # hmm what?

By looking at the implementation which uses dev_uc_add/dev_uc_del it is
absolutely clear that only local addresses are supported, and the proper
Network Unreachability Detection state is being used for this purpose
(user space indeed sets NUD_PERMANENT when local addresses are meant).
So it is just the message that is wrong, fix it.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: use netdev_info in ndo_dflt_fdb_{add,del}

Use the more modern printk helper for network interfaces, which also
contains information about the associated struct device, and results in
overall shorter line lengths compared to printing an open-coded
dev->name.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

wwan: add interface creation support

Add support to create (and destroy) interfaces via a new
rtnetlink kind "wwan". The responsible driver has to use
the new wwan_register_ops() to make this possible.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: add IFLA_PARENT_[DEV|DEV_BUS]_NAME

In some cases, for example in the upcoming WWAN framework changes,
there's no natural "parent netdev", so sometimes dummy netdevs are
created or similar. IFLA_PARENT_DEV_NAME is a new attribute intended to
contain a device (sysfs, struct device) name that can be used instead
when creating a new netdev, if the rtnetlink family implements it.

As suggested by Parav Pandit, we also introduce IFLA_PARENT_DEV_BUS_NAME
attribute in order to uniquely identify a device on the system (with
bus/name pair).

ip-link(8) support for the generic parent device attributes will help
us avoid code duplication, so no other link type will require a custom
code to handle the parent name attribute. E.g. the WWAN interface
creation command will looks like this:

$ ip link add wwan0-1 parent-dev wwan0 type wwan channel-id 1

So, some future subsystem (or driver) FOO will have an interface
creation command that looks like this:

$ ip link add foo1-3 parent-dev foo1 type foo bar-id 3 baz-type Y

Below is an example of dumping link info of a random device with these
new attributes:

$ ip --details link show wlp0s20f3
4: wlp0s20f3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue
state UP mode DORMANT group default qlen 1000
...
parent_bus pci parent_dev 0000:00:14.3

Co-developed-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Co-developed-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Suggested-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: add alloc() method to rtnl_link_ops

In order to make rtnetlink ops that can create different
kinds of devices, like what we want to add to the WWAN
framework, the priv_size and setup parameters aren't quite
sufficient. Make this easier to manage by allowing ops to
allocate their own netdev via an @alloc method that gets
the tb netlink data.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Fix spelling mistakes

Signed-off-by: Zheng Yongjun <zhengyongjun3@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: avoid RCU read lock when holding RTNL

When we call af_ops->set_link_af() we hold a RCU read lock
as we retrieve af_ops from the RCU protected list, but this
is unnecessary because we already hold RTNL lock, which is
the writer lock for protecting rtnl_af_ops, so it is safer
than RCU read lock. Similar for af_ops->validate_link_af().

This was not a problem until we begin to take mutex lock
down the path of ->set_link_af() in __ipv6_dev_mc_dec()
recently. We can just drop the RCU read lock there and
assert RTNL lock.

Reported-and-tested-by: syzbot+7d941e89dd48bcf42573@syzkaller.appspotmail.com
Fixes: 63ed8de4be81 ("mld: add mc_lock for protecting per-interface mld data")
Tested-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Fix regression in bridge VLAN configuration

Cited commit started returning errors when notification info is not
filled by the bridge driver, resulting in the following regression:

# ip link add name br1 type bridge vlan_filtering 1
# bridge vlan add dev br1 vid 555 self pvid untagged
RTNETLINK answers: Invalid argument

As long as the bridge driver does not fill notification info for the
bridge device itself, an empty notification should not be considered as
an error. This is explained in commit 59ccaaaa49b5 ("bridge: dont send
notification when skb->len == 0 in rtnl_bridge_notify").

Fix by removing the error and add a comment to avoid future bugs.

Fixes: a8db57c1d285 ("rtnetlink: Fix missing error code in rtnl_bridge_notify()")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Fix missing error code in rtnl_bridge_notify()

The error code is missing in this code scenario, add the error code
'-EINVAL' to the return value 'err'.

Eliminate the follow smatch warning:

net/core/rtnetlink.c:4834 rtnl_bridge_notify() warn: missing error code
'err'.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: remove the new_ifindex argument from dev_change_net_namespace

Here is only one place where we want to specify new_ifindex. In all
other cases, callers pass 0 as new_ifindex. It looks reasonable to add a
low-level function with new_ifindex and to convert
dev_change_net_namespace to a static inline wrapper.

Fixes: eeb85a14ee34 ("net: Allow to specify ifindex when device is moved to another namespace")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: introduce nla_policy for IFLA_NEW_IFINDEX

In this case, we don't need to check that new_ifindex is positive in
validate_linkmsg.

Fixes: eeb85a14ee34 ("net: Allow to specify ifindex when device is moved to another namespace")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Allow to specify ifindex when device is moved to another namespace

Currently, we can specify ifindex on link creation. This change allows
to specify ifindex when a device is moved to another network namespace.

Even now, a device ifindex can be changed if there is another device
with the same ifindex in the target namespace. So this change doesn't
introduce completely new behavior, it adds more control to the process.

CRIU users want to restore containers with pre-created network devices.
A user will provide network devices and instructions where they have to
be restored, then CRIU will restore network namespaces and move devices
into them. The problem is that devices have to be restored with the same
indexes that they have before C/R.

Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com>
Suggested-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipv6: report errors for iftoken via netlink extack

Setting iftoken can fail for several different reasons but there
and there was no report to user as to the cause. Add netlink
extended errors to the processing of the request.

This requires adding additional argument through rtnl_af_ops
set_link_af callback.

Reported-by: Hongren Zheng <li@zenithal.me>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: using dev_base_seq from target net

Signed-off-by: zhang kai <zhangkaiheb@126.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: fix dev_ifsioc_locked() race condition

dev_ifsioc_locked() is called with only RCU read lock, so when
there is a parallel writer changing the mac address, it could
get a partially updated mac address, as shown below:

Thread 1 Thread 2
// eth_commit_mac_addr_change()
memcpy(dev->dev_addr, addr->sa_data, ETH_ALEN);
// dev_ifsioc_locked()
memcpy(ifr->ifr_hwaddr.sa_data,
dev->dev_addr,...);

Close this race condition by guarding them with a RW semaphore,
like netdev_get_name(). We can not use seqlock here as it does not
allow blocking. The writers already take RTNL anyway, so this does
not affect the slow path. To avoid bothering existing
dev_set_mac_address() callers in drivers, introduce a new wrapper
just for user-facing callers on ioctl and rtnetlink paths.

Note, bonding also changes slave mac addresses but that requires
a separate patch due to the complexity of bonding code.

Fixes: 3710becf8a58 ("net: RCU locking for simple ioctl()")
Reported-by: "Gong, Sishuai" <sishuai@purdue.edu>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: bridge: multicast: make tracked EHT hosts limit configurable

Add two new port attributes which make EHT hosts limit configurable and
export the current number of tracked EHT hosts:
- IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT: configure/retrieve current limit
- IFLA_BRPORT_MCAST_EHT_HOSTS_CNT: current number of tracked hosts
Setting IFLA_BRPORT_MCAST_EHT_HOSTS_LIMIT to 0 is currently not allowed.

Note that we have to increase RTNL_SLAVE_MAX_TYPE to 38 minimum, I've
increased it to 40 to have space for two more future entries.

v2: move br_multicast_eht_set_hosts_limit() to br_multicast_eht.c,
no functional change

Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: make free_netdev() more lenient with unregistering devices

There are two flavors of handling netdev registration:
- ones called without holding rtnl_lock: register_netdev() and
unregister_netdev(); and
- those called with rtnl_lock held: register_netdevice() and
unregister_netdevice().

While the semantics of the former are pretty clear, the same can't
be said about the latter. The netdev_todo mechanism is utilized to
perform some of the device unregistering tasks and it hooks into
rtnl_unlock() so the locked variants can't actually finish the work.
In general free_netdev() does not mix well with locked calls. Most
drivers operating under rtnl_lock set dev->needs_free_netdev to true
and expect core to make the free_netdev() call some time later.

The part where this becomes most problematic is error paths. There is
no way to unwind the state cleanly after a call to register_netdevice(),
since unreg can't be performed fully without dropping locks.

Make free_netdev() more lenient, and defer the freeing if device
is being unregistered. This allows error paths to simply call
free_netdev() both after register_netdevice() failed, and after
a call to unregister_netdevice() but before dropping rtnl_lock.

Simplify the error paths which are currently doing gymnastics
around free_netdev() handling.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

docs: net: explain struct net_device lifetime

Explain the two basic flows of struct net_device's operation.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: RCU-annotate both dimensions of rtnl_msg_handlers

We use rcu_assign_pointer to assign both the table and the entries,
but the entries are not marked as __rcu. This generates sparse
warnings.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: rename nla_strlcpy to nla_strscpy.

Calls to nla_strlcpy are now replaced by calls to nla_strscpy which is the new
name of this function.

Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: fix data overflow in rtnl_calcit()

"ip addr show" command execute error when we have a physical
network card with a large number of VFs

The return value of if_nlmsg_size() in rtnl_calcit() will exceed
range of u16 data type when any network cards has a larger number of
VFs. rtnl_vfinfo_size() will significant increase needed dump size when
the value of num_vfs is larger.

Eventually we get a wrong value of min_ifinfo_dump_size because of overflow
which decides the memory size needed by netlink dump and netlink_dump()
will return -EMSGSIZE because of not enough memory was allocated.

So fix it by promoting min_dump_alloc data type to u32 to
avoid whole netlink message size overflow and it's also align
with the data type of struct netlink_callback{}.min_dump_alloc
which is assigned by return value of rtnl_calcit()

Signed-off-by: Di Zhu <zhudi21@huawei.com>
Link: https://lore.kernel.org/r/20201021020053.1401-1-zhudi21@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

rtnetlink: add support for protodown reason

netdev protodown is a mechanism that allows protocols to
hold an interface down. It was initially introduced in
the kernel to hold links down by a multihoming protocol.
There was also an attempt to introduce protodown
reason at the time but was rejected. protodown and protodown reason
is supported by almost every switching and routing platform.
It was ok for a while to live without a protodown reason.
But, its become more critical now given more than
one protocol may need to keep a link down on a system
at the same time. eg: vrrp peer node, port security,
multihoming protocol. Its common for Network operators and
protocol developers to look for such a reason on a networking
box (Its also known as errDisable by most networking operators)

This patch adds support for link protodown reason
attribute. There are two ways to maintain protodown
reasons.
(a) enumerate every possible reason code in kernel
- A protocol developer has to make a request and
have that appear in a certain kernel version
(b) provide the bits in the kernel, and allow user-space
(sysadmin or NOS distributions) to manage the bit-to-reasonname
map.
- This makes extending reason codes easier (kind of like
the iproute2 table to vrf-name map /etc/iproute2/rt_tables.d/)

This patch takes approach (b).

a few things about the patch:
- It treats the protodown reason bits as counter to indicate
active protodown users
- Since protodown attribute is already an exposed UAPI,
the reason is not enforced on a protodown set. Its a no-op
if not used.
the patch follows the below algorithm:
- presence of reason bits set indicates protodown
is in use
- user can set protodown and protodown reason in a
single or multiple setlink operations
- setlink operation to clear protodown, will return -EBUSY
if there are active protodown reason bits
- reason is not included in link dumps if not used

example with patched iproute2:
$cat /etc/iproute2/protodown_reasons.d/r.conf
0 mlag
1 evpn
2 vrrp
3 psecurity

$ip link set dev vxlan0 protodown on protodown_reason vrrp on
$ip link set dev vxlan0 protodown_reason mlag on
$ip link show
14: vxlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode
DEFAULT group default qlen 1000
link/ether f6:06:be:17:91:e7 brd ff:ff:ff:ff:ff:ff protodown on <mlag,vrrp>

$ip link set dev vxlan0 protodown_reason mlag off
$ip link set dev vxlan0 protodown off protodown_reason vrrp off

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

bpf, xdp: Maintain info on attached XDP BPF programs in net_device

Instead of delegating to drivers, maintain information about which BPF
programs are attached in which XDP modes (generic/skb, driver, or hardware)
locally in net_device. This effectively obsoletes XDP_QUERY_PROG command.

Such re-organization simplifies existing code already. But it also allows to
further add bpf_link-based XDP attachments without drivers having to know
about any of this at all, which seems like a good setup.
XDP_SETUP_PROG/XDP_SETUP_PROG_HW are just low-level commands to driver to
install/uninstall active BPF program. All the higher-level concerns about
prog/link interaction will be contained within generic driver-agnostic logic.

All the XDP_QUERY_PROG calls to driver in dev_xdp_uninstall() were removed.
It's not clear for me why dev_xdp_uninstall() were passing previous prog_flags
when resetting installed programs. That seems unnecessary, plus most drivers
don't populate prog_flags anyways. Having XDP_SETUP_PROG vs XDP_SETUP_PROG_HW
should be enough of an indicator of what is required of driver to correctly
reset active BPF program. dev_xdp_uninstall() is also generalized as an
iteration over all three supported mode.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200722064603.3350758-3-andriin@fb.com

rtnetlink: Fix memory(net_device) leak when ->newlink fails

When vlan_newlink call register_vlan_dev fails, it might return error
with dev->reg_state = NETREG_UNREGISTERED. The rtnl_newlink should
free the memory. But currently rtnl_newlink only free the memory which
state is NETREG_UNINITIALIZED.

BUG: memory leak
unreferenced object 0xffff8881051de000 (size 4096):
comm "syz-executor139", pid 560, jiffies 4294745346 (age 32.445s)
hex dump (first 32 bytes):
76 6c 61 6e 32 00 00 00 00 00 00 00 00 00 00 00 vlan2...........
00 45 28 03 81 88 ff ff 00 00 00 00 00 00 00 00 .E(.............
backtrace:
[<0000000047527e31>] kmalloc_node include/linux/slab.h:578 [inline]
[<0000000047527e31>] kvmalloc_node+0x33/0xd0 mm/util.c:574
[<000000002b59e3bc>] kvmalloc include/linux/mm.h:753 [inline]
[<000000002b59e3bc>] kvzalloc include/linux/mm.h:761 [inline]
[<000000002b59e3bc>] alloc_netdev_mqs+0x83/0xd90 net/core/dev.c:9929
[<000000006076752a>] rtnl_create_link+0x2c0/0xa20 net/core/rtnetlink.c:3067
[<00000000572b3be5>] __rtnl_newlink+0xc9c/0x1330 net/core/rtnetlink.c:3329
[<00000000e84ea553>] rtnl_newlink+0x66/0x90 net/core/rtnetlink.c:3397
[<0000000052c7c0a9>] rtnetlink_rcv_msg+0x540/0x990 net/core/rtnetlink.c:5460
[<000000004b5cb379>] netlink_rcv_skb+0x12b/0x3a0 net/netlink/af_netlink.c:2469
[<00000000c71c20d3>] netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
[<00000000c71c20d3>] netlink_unicast+0x4c6/0x690 net/netlink/af_netlink.c:1329
[<00000000cca72fa9>] netlink_sendmsg+0x735/0xcc0 net/netlink/af_netlink.c:1918
[<000000009221ebf7>] sock_sendmsg_nosec net/socket.c:652 [inline]
[<000000009221ebf7>] sock_sendmsg+0x109/0x140 net/socket.c:672
[<000000001c30ffe4>] ____sys_sendmsg+0x5f5/0x780 net/socket.c:2352
[<00000000b71ca6f3>] ___sys_sendmsg+0x11d/0x1a0 net/socket.c:2406
[<0000000007297384>] __sys_sendmsg+0xeb/0x1b0 net/socket.c:2439
[<000000000eb29b11>] do_syscall_64+0x56/0xa0 arch/x86/entry/common.c:359
[<000000006839b4d0>] entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: cb626bf566eb ("net-sysfs: Fix reference count leak")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: change addr_list_lock back to static key

The dynamic key update for addr_list_lock still causes troubles,
for example the following race condition still exists:

CPU 0: CPU 1:
(RCU read lock) (RTNL lock)
dev_mc_seq_show() netdev_update_lockdep_key()
-> lockdep_unregister_key()
-> netif_addr_lock_bh()

because lockdep doesn't provide an API to update it atomically.
Therefore, we have to move it back to static keys and use subclass
for nest locking like before.

In commit 1a33e10e4a95 ("net: partially revert dynamic lockdep key
changes"), I already reverted most parts of commit ab92d68fc22f
("net: core: add generic lockdep keys").

This patch reverts the rest and also part of commit f3b0a18bb6cb
("net: remove unnecessary variables and callback"). After this
patch, addr_list_lock changes back to using static keys and
subclasses to satisfy lockdep. Thanks to dev->lower_level, we do
not have to change back to ->ndo_get_lock_subclass().

And hopefully this reduces some syzbot lockdep noises too.

Reported-by: syzbot+f3a0e80c34b3fc28ac5e@syzkaller.appspotmail.com
Cc: Taehee Yoo <ap420073@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: remove redundant assignment to variable err

The variable err is being initializeed with a value that is never read
and it is being updated later with a new value. The initialization
is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add IF_OPER_TESTING

RFC 2863 defines the operational state testing. Add support for this
state, both as a IF_LINK_MODE_ and __LINK_STATE_.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

xdp: Support specifying expected existing program when attaching XDP

While it is currently possible for userspace to specify that an existing
XDP program should not be replaced when attaching to an interface, there is
no mechanism to safely replace a specific XDP program with another.

This patch adds a new netlink attribute, IFLA_XDP_EXPECTED_FD, which can be
set along with IFLA_XDP_FD. If set, the kernel will check that the program
currently loaded on the interface matches the expected one, and fail the
operation if it does not. This corresponds to a 'cmpxchg' memory operation.
Setting the new attribute with a negative value means that no program is
expected to be attached, which corresponds to setting the UPDATE_IF_NOEXIST
flag.

A new companion flag, XDP_FLAGS_REPLACE, is also added to explicitly
request checking of the EXPECTED_FD attribute. This is needed for userspace
to discover whether the kernel supports the new attribute.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/bpf/158515700640.92963.3551295145441017022.stgit@toke.dk

net: use netif_is_bridge_port() to check for IFF_BRIDGE_PORT

Trivial cleanup, so that all bridge port-specific code can be found in
one go.

CC: Johannes Berg <johannes@sipsolutions.net>
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
CC: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: bridge: teach ndo_dflt_bridge_getlink() more brport flags

This enables ndo_dflt_bridge_getlink() to report a bridge port's
offload settings for multicast and broadcast flooding.

CC: Roopa Prabhu <roopa@cumulusnetworks.com>
CC: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: fix bugs in rtnl_alt_ifname()

Since IFLA_ALT_IFNAME is an NLA_STRING, we have no
guarantee it is nul terminated.

We should use nla_strdup() instead of kstrdup(), since this
helper will make sure not accessing out-of-bounds data.

BUG: KMSAN: uninit-value in strlen+0x5e/0xa0 lib/string.c:535
CPU: 1 PID: 19157 Comm: syz-executor.5 Not tainted 5.5.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1c9/0x220 lib/dump_stack.c:118
kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
__msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
strlen+0x5e/0xa0 lib/string.c:535
kstrdup+0x7f/0x1a0 mm/util.c:59
rtnl_alt_ifname net/core/rtnetlink.c:3495 [inline]
rtnl_linkprop+0x85d/0xc00 net/core/rtnetlink.c:3553
rtnl_newlinkprop+0x9d/0xb0 net/core/rtnetlink.c:3568
rtnetlink_rcv_msg+0x1153/0x1570 net/core/rtnetlink.c:5424
netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2477
rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5442
netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1328
netlink_sendmsg+0x1248/0x14d0 net/netlink/af_netlink.c:1917
sock_sendmsg_nosec net/socket.c:639 [inline]
sock_sendmsg net/socket.c:659 [inline]
____sys_sendmsg+0x12b6/0x1350 net/socket.c:2330
___sys_sendmsg net/socket.c:2384 [inline]
__sys_sendmsg+0x451/0x5f0 net/socket.c:2417
__do_sys_sendmsg net/socket.c:2426 [inline]
__se_sys_sendmsg+0x97/0xb0 net/socket.c:2424
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424
do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45b3b9
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ff1c7b1ac78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff1c7b1b6d4 RCX: 000000000045b3b9
RDX: 0000000000000000 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000009cb R14: 00000000004cb3dd R15: 000000000075bf2c

Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82
slab_alloc_node mm/slub.c:2774 [inline]
__kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4382
__kmalloc_reserve net/core/skbuff.c:141 [inline]
__alloc_skb+0x2fd/0xac0 net/core/skbuff.c:209
alloc_skb include/linux/skbuff.h:1049 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1174 [inline]
netlink_sendmsg+0x7d3/0x14d0 net/netlink/af_netlink.c:1892
sock_sendmsg_nosec net/socket.c:639 [inline]
sock_sendmsg net/socket.c:659 [inline]
____sys_sendmsg+0x12b6/0x1350 net/socket.c:2330
___sys_sendmsg net/socket.c:2384 [inline]
__sys_sendmsg+0x451/0x5f0 net/socket.c:2417
__do_sys_sendmsg net/socket.c:2426 [inline]
__se_sys_sendmsg+0x97/0xb0 net/socket.c:2424
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2424
do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: 36fbf1e52bd3 ("net: rtnetlink: add linkprop commands to add and delete alternative ifnames")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core: Do not clear VF index for node/port GUIDs query

VF numbers were assigned to node_guid and port_guid, but cleared
right before such query calls were issued. It caused to return
node/port GUIDs of VF index 0 for all VFs.

Fixes: 30aad41721e0 ("net/core: Add support for getting VF GUIDs")
Reported-by: Adrian Chiris <adrianc@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: validate IFLA_MTU attribute in rtnl_create_link()

rtnl_create_link() needs to apply dev->min_mtu and dev->max_mtu
checks that we apply in do_setlink()

Otherwise malicious users can crash the kernel, for example after
an integer overflow :

BUG: KASAN: use-after-free in memset include/linux/string.h:365 [inline]
BUG: KASAN: use-after-free in __alloc_skb+0x37b/0x5e0 net/core/skbuff.c:238
Write of size 32 at addr ffff88819f20b9c0 by task swapper/0/0

CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x197/0x210 lib/dump_stack.c:118
print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
__kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
kasan_report+0x12/0x20 mm/kasan/common.c:639
check_memory_region_inline mm/kasan/generic.c:185 [inline]
check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192
memset+0x24/0x40 mm/kasan/common.c:108
memset include/linux/string.h:365 [inline]
__alloc_skb+0x37b/0x5e0 net/core/skbuff.c:238
alloc_skb include/linux/skbuff.h:1049 [inline]
alloc_skb_with_frags+0x93/0x590 net/core/skbuff.c:5664
sock_alloc_send_pskb+0x7ad/0x920 net/core/sock.c:2242
sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2259
mld_newpack+0x1d7/0x7f0 net/ipv6/mcast.c:1609
add_grhead.isra.0+0x299/0x370 net/ipv6/mcast.c:1713
add_grec+0x7db/0x10b0 net/ipv6/mcast.c:1844
mld_send_cr net/ipv6/mcast.c:1970 [inline]
mld_ifc_timer_expire+0x3d3/0x950 net/ipv6/mcast.c:2477
call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404
expire_timers kernel/time/timer.c:1449 [inline]
__run_timers kernel/time/timer.c:1773 [inline]
__run_timers kernel/time/timer.c:1740 [inline]
run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786
__do_softirq+0x262/0x98c kernel/softirq.c:292
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x19b/0x1e0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:536 [inline]
smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
</IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: 98 6b ea f9 eb 8a cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 44 1c 60 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 34 1c 60 00 fb f4 <c3> cc 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 4e 5d 9a f9 e8 79
RSP: 0018:ffffffff89807ce8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff13266ae RBX: ffffffff8987a1c0 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff8987aa54
RBP: ffffffff89807d18 R08: ffffffff8987a1c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffffff8a799980 R14: 0000000000000000 R15: 0000000000000000
arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:690
default_idle_call+0x84/0xb0 kernel/sched/idle.c:94
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x3c8/0x6e0 kernel/sched/idle.c:269
cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:361
rest_init+0x23b/0x371 init/main.c:451
arch_call_rest_init+0xe/0x1b
start_kernel+0x904/0x943 init/main.c:784
x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490
x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:471
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242

The buggy address belongs to the page:
page:ffffea00067c82c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
raw: 057ffe0000000000 ffffea00067c82c8 ffffea00067c82c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88819f20b880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88819f20b900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88819f20b980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff88819f20ba00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff88819f20ba80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

Fixes: 61e84623ace3 ("net: centralize net_device min/max MTU checking")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: provide permanent hardware address in RTM_NEWLINK

Permanent hardware address of a network device was traditionally provided
via ethtool ioctl interface but as Jiri Pirko pointed out in a review of
ethtool netlink interface, rtnetlink is much more suitable for it so let's
add it to the RTM_NEWLINK message.

Add IFLA_PERM_ADDRESS attribute to RTM_NEWLINK messages unless the
permanent address is all zeros (i.e. device driver did not fill it). As
permanent address is not modifiable, reject userspace requests containing
IFLA_PERM_ADDRESS attribute.

Note: we already provide permanent hardware address for bond slaves;
unfortunately we cannot drop that attribute for backward compatibility
reasons.

v5 -> v6: only add the attribute if permanent address is not zero

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core: Populate VF index in struct ifla_vf_guid

In addition to filling the node_guid and port_guid attributes,
there is a need to populate VF index too, otherwise users of netlink
interface will see same VF index for all VFs.

Fixes: 30aad41721e0 ("net/core: Add support for getting VF GUIDs")
Signed-off-by: Danit Goldberg <danitg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: prevent underflows in do_setvfinfo()

The "ivm->vf" variable is a u32, but the problem is that a number of
drivers cast it to an int and then forget to check for negatives. An
example of this is in the cxgb4 driver.

drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c
2890 static int cxgb4_mgmt_get_vf_config(struct net_device *dev,
2891 int vf, struct ifla_vf_info *ivi)
^^^^^^
2892 {
2893 struct port_info *pi = netdev_priv(dev);
2894 struct adapter *adap = pi->adapter;
2895 struct vf_info *vfinfo;
2896
2897 if (vf >= adap->num_vfs)
^^^^^^^^^^^^^^^^^^^
2898 return -EINVAL;
2899 vfinfo = &adap->vfinfo[vf];
^^^^^^^^^^^^^^^^^^^^^^^^^^

There are 48 functions affected.

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c:8435 hclge_set_vf_vlan_filter() warn: can 'vfid' underflow 's32min-2147483646'
drivers/net/ethernet/freescale/enetc/enetc_pf.c:377 enetc_pf_set_vf_mac() warn: can 'vf' underflow 's32min-2147483646'
drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:2899 cxgb4_mgmt_get_vf_config() warn: can 'vf' underflow 's32min-254'
drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:2960 cxgb4_mgmt_set_vf_rate() warn: can 'vf' underflow 's32min-254'
drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:3019 cxgb4_mgmt_set_vf_rate() warn: can 'vf' underflow 's32min-254'
drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:3038 cxgb4_mgmt_set_vf_vlan() warn: can 'vf' underflow 's32min-254'
drivers/net/ethernet/chelsio/cxgb4/cxgb4_main.c:3086 cxgb4_mgmt_set_vf_link_state() warn: can 'vf' underflow 's32min-254'
drivers/net/ethernet/chelsio/cxgb/cxgb2.c:791 get_eeprom() warn: can 'i' underflow 's32min-(-4),0,4-s32max'
drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c:82 bnxt_set_vf_spoofchk() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c:164 bnxt_set_vf_trust() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c:186 bnxt_get_vf_config() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c:228 bnxt_set_vf_mac() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c:264 bnxt_set_vf_vlan() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c:293 bnxt_set_vf_bw() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c:333 bnxt_set_vf_link_state() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c:2595 bnx2x_vf_op_prep() warn: can 'vfidx' underflow 's32min-63'
drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c:2595 bnx2x_vf_op_prep() warn: can 'vfidx' underflow 's32min-63'
drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c:2281 bnx2x_post_vf_bulletin() warn: can 'vf' underflow 's32min-63'
drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c:2285 bnx2x_post_vf_bulletin() warn: can 'vf' underflow 's32min-63'
drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c:2286 bnx2x_post_vf_bulletin() warn: can 'vf' underflow 's32min-63'
drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c:2292 bnx2x_post_vf_bulletin() warn: can 'vf' underflow 's32min-63'
drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c:2297 bnx2x_post_vf_bulletin() warn: can 'vf' underflow 's32min-63'
drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c:1832 qlcnic_sriov_set_vf_mac() warn: can 'vf' underflow 's32min-254'
drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c:1864 qlcnic_sriov_set_vf_tx_rate() warn: can 'vf' underflow 's32min-254'
drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c:1937 qlcnic_sriov_set_vf_vlan() warn: can 'vf' underflow 's32min-254'
drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c:2005 qlcnic_sriov_get_vf_config() warn: can 'vf' underflow 's32min-254'
drivers/net/ethernet/qlogic/qlcnic/qlcnic_sriov_pf.c:2036 qlcnic_sriov_set_vf_spoofchk() warn: can 'vf' underflow 's32min-254'
drivers/net/ethernet/emulex/benet/be_main.c:1914 be_get_vf_config() warn: can 'vf' underflow 's32min-65534'
drivers/net/ethernet/emulex/benet/be_main.c:1915 be_get_vf_config() warn: can 'vf' underflow 's32min-65534'
drivers/net/ethernet/emulex/benet/be_main.c:1922 be_set_vf_tvt() warn: can 'vf' underflow 's32min-65534'
drivers/net/ethernet/emulex/benet/be_main.c:1951 be_clear_vf_tvt() warn: can 'vf' underflow 's32min-65534'
drivers/net/ethernet/emulex/benet/be_main.c:2063 be_set_vf_tx_rate() warn: can 'vf' underflow 's32min-65534'
drivers/net/ethernet/emulex/benet/be_main.c:2091 be_set_vf_link_state() warn: can 'vf' underflow 's32min-65534'
drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c:2609 ice_set_vf_port_vlan() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c:3050 ice_get_vf_cfg() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c:3103 ice_set_vf_spoofchk() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c:3181 ice_set_vf_mac() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c:3237 ice_set_vf_trust() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c:3286 ice_set_vf_link_state() warn: can 'vf_id' underflow 's32min-65534'
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:3919 i40e_validate_vf() warn: can 'vf_id' underflow 's32min-2147483646'
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:3957 i40e_ndo_set_vf_mac() warn: can 'vf_id' underflow 's32min-2147483646'
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:4104 i40e_ndo_set_vf_port_vlan() warn: can 'vf_id' underflow 's32min-2147483646'
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:4263 i40e_ndo_set_vf_bw() warn: can 'vf_id' underflow 's32min-2147483646'
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:4309 i40e_ndo_get_vf_config() warn: can 'vf_id' underflow 's32min-2147483646'
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:4371 i40e_ndo_set_vf_link_state() warn: can 'vf_id' underflow 's32min-2147483646'
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:4441 i40e_ndo_set_vf_spoofchk() warn: can 'vf_id' underflow 's32min-2147483646'
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:4441 i40e_ndo_set_vf_spoofchk() warn: can 'vf_id' underflow 's32min-2147483646'
drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c:4504 i40e_ndo_set_vf_trust() warn: can 'vf_id' underflow 's32min-2147483646'

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core: Add support for getting VF GUIDs

Introduce a new ndo: ndo_get_vf_guid, to get from the net
device the port and node GUID.

New applications can choose to use this interface to show
GUIDs with iproute2 with commands such as:

- ip link show ib4
ib4: <BROADCAST,MULTICAST> mtu 4092 qdisc noop state DOWN mode DEFAULT group default qlen 256
link/infiniband 00:00:0a:2d:fe:80:00:00:00:00:00:00:ec:0d:9a:03:00:44:36:8d brd 00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff
vf 0 link/infiniband 00:00:0a:2d:fe:80:00:00:00:00:00:00:ec:0d:9a:03:00:44:36:8d brd 00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff,
spoof checking off, NODE_GUID 22:44:33:00:33:11:00:33, PORT_GUID 10:21:33:12:00:11:22:10, link-state disable, trust off, query_rss off

Signed-off-by: Danit Goldberg <danitg@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>

net: rtnetlink: fix a typo fbd -> fdb

A simple typo fix in the nl error message (fbd -> fdb).

CC: David Ahern <dsahern@gmail.com>
Fixes: 8c6e137fbc7f ("rtnetlink: Update rtnl_fdb_dump for strict data checking")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netns: fix GFP flags in rtnl_net_notifyid()

In rtnl_net_notifyid(), we certainly can't pass a null GFP flag to
rtnl_notify(). A GFP_KERNEL flag would be fine in most circumstances,
but there are a few paths calling rtnl_net_notifyid() from atomic
context or from RCU critical sections. The later also precludes the use
of gfp_any() as it wouldn't detect the RCU case. Also, the nlmsg_new()
call is wrong too, as it uses GFP_KERNEL unconditionally.

Therefore, we need to pass the GFP flags as parameter and propagate it
through function calls until the proper flags can be determined.

In most cases, GFP_KERNEL is fine. The exceptions are:
* openvswitch: ovs_vport_cmd_get() and ovs_vport_cmd_dump()
indirectly call rtnl_net_notifyid() from RCU critical section,

* rtnetlink: rtmsg_ifinfo_build_skb() already receives GFP flags as
parameter.

Also, in ovs_vport_cmd_build_info(), let's change the GFP flags used
by nlmsg_new(). The function is allowed to sleep, so better make the
flags consistent with the ones used in the following
ovs_vport_cmd_fill_info() call.

Found by code inspection.

Fixes: 9a9634545c70 ("netns: notify netns id events")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: add generic lockdep keys

Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
- qdisc_running, xmit, addr_list, qdisc_busylock
- these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
- alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
- free_netdev()
d) Add generic lockdep key helper function
- netdev_register_lockdep_key()
- netdev_unregister_lockdep_key()
- netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: add possibility to use alternative names as message handle

Extend the basic rtnetlink commands to use alternative interface names
as a handle instead of ifindex and ifname.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: introduce helper to get net_device instance by ifname

Introduce helper function rtnl_get_dev() that gets net_device structure
instance pointer according to passed ifname or ifname attribute.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: unify the code in __rtnl_newlink get dev with the rest

__rtnl_newlink() code flow is a bit different around tb[IFLA_IFNAME]
processing comparing to the other places. Change that to be unified with
the rest.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: put alternative names to getlink message

Extend exiting getlink info message with list of properties. Now the
only ones are alternative names.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: add linkprop commands to add and delete alternative ifnames

Add two commands to add and delete list of link properties. Implement
the first property type along - alternative ifnames.
Each net device can have multiple alternative names.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: skip metrics loop for dst_default_metrics

dst_default_metrics has all of the metrics initialized to 0, so nothing
will be added to the skb in rtnetlink_put_metrics. Avoid the loop if
metrics is from dst_default_metrics.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ipoib: show VF broadcast address

in IPoIB case we can't see a VF broadcast address for but
can see for PF

Before:
11: ib1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 2044 qdisc pfifo_fast
state UP mode DEFAULT group default qlen 256
link/infiniband
80:00:00:66:fe:80:00:00:00:00:00:00:24:8a:07:03:00:a4:3e:7c brd
00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff
vf 0 MAC 14:80:00:00:66:fe, spoof checking off, link-state disable,
trust off, query_rss off
...

After:
11: ib1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 2044 qdisc pfifo_fast
state UP mode DEFAULT group default qlen 256
link/infiniband
80:00:00:66:fe:80:00:00:00:00:00:00:24:8a:07:03:00:a4:3e:7c brd
00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff
vf 0 link/infiniband
80:00:00:66:fe:80:00:00:00:00:00:00:24:8a:07:03:00:a4:3e:7c brd
00:ff:ff:ff:ff:12:40:1b:ff:ff:00:00:00:00:00:00:ff:ff:ff:ff, spoof
checking off, link-state disable, trust off, query_rss off

v1->v2: add the IFLA_VF_BROADCAST constant
v2->v3: put IFLA_VF_BROADCAST at the end
to avoid KABI breakage and set NLA_REJECT
dev_setlink

Signed-off-by: Denis Kirjanov <kda@linux-powerpc.org>
Acked-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

rtnetlink: always put IFLA_LINK for links with a link-netnsid

Currently, nla_put_iflink() doesn't put the IFLA_LINK attribute when
iflink == ifindex.

In some cases, a device can be created in a different netns with the
same ifindex as its parent. That device will not dump its IFLA_LINK
attribute, which can confuse some userspace software that expects it.
For example, if the last ifindex created in init_net and foo are both
8, these commands will trigger the issue:

ip link add parent type dummy # ifindex 9
ip link add link parent netns foo type macvlan # ifindex 9 in ns foo

So, in case a device puts the IFLA_LINK_NETNSID attribute in a dump,
always put the IFLA_LINK attribute as well.

Thanks to Dan Winship for analyzing the original OpenShift bug down to
the missing netlink attribute.

v2: change Fixes tag, it's been here forever, as Nicolas Dichtel said
add Nicolas' ack
v3: change Fixes tag
fix subject typo, spotted by Edward Cree

Analyzed-by: Dan Winship <danw@redhat.com>
Fixes: d8a5ec672768 ("[NET]: netlink support for moving devices between network namespaces.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: make validation more configurable for future strictness

We currently have two levels of strict validation:

1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected accepted

Split out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute size

The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().

Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.

We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecated

Using spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)

@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)

@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)

@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)

@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)

@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)

For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.

Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.

Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.

In effect then, this adds fully strict validation for any new command.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netlink: make nla_nest_start() add NLA_F_NESTED flag

Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: fix rtnl_valid_stats_req() nlmsg_len check

Jakub forgot to either use nlmsg_len() or nlmsg_msg_size(),
allowing KMSAN to detect a possible uninit-value in rtnl_stats_get

BUG: KMSAN: uninit-value in rtnl_stats_get+0x6d9/0x11d0 net/core/rtnetlink.c:4997
CPU: 0 PID: 10428 Comm: syz-executor034 Not tainted 5.1.0-rc2+ #24
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x173/0x1d0 lib/dump_stack.c:113
kmsan_report+0x131/0x2a0 mm/kmsan/kmsan.c:619
__msan_warning+0x7a/0xf0 mm/kmsan/kmsan_instr.c:310
rtnl_stats_get+0x6d9/0x11d0 net/core/rtnetlink.c:4997
rtnetlink_rcv_msg+0x115b/0x1550 net/core/rtnetlink.c:5192
netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2485
rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:5210
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1336
netlink_sendmsg+0x127f/0x1300 net/netlink/af_netlink.c:1925
sock_sendmsg_nosec net/socket.c:622 [inline]
sock_sendmsg net/socket.c:632 [inline]
___sys_sendmsg+0xdb3/0x1220 net/socket.c:2137
__sys_sendmsg net/socket.c:2175 [inline]
__do_sys_sendmsg net/socket.c:2184 [inline]
__se_sys_sendmsg+0x305/0x460 net/socket.c:2182
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2182
do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7

Fixes: 51bc860d4a99 ("rtnetlink: stats: validate attributes in get as well as dumps")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core: Fix rtnetlink kernel-doc headers

This patch avoids that the following warnings are reported when building
with W=1:

net/core/rtnetlink.c:3580: warning: Function parameter or member 'ndm' not described in 'ndo_dflt_fdb_add'
net/core/rtnetlink.c:3580: warning: Function parameter or member 'tb' not described in 'ndo_dflt_fdb_add'
net/core/rtnetlink.c:3580: warning: Function parameter or member 'dev' not described in 'ndo_dflt_fdb_add'
net/core/rtnetlink.c:3580: warning: Function parameter or member 'addr' not described in 'ndo_dflt_fdb_add'
net/core/rtnetlink.c:3580: warning: Function parameter or member 'vid' not described in 'ndo_dflt_fdb_add'
net/core/rtnetlink.c:3580: warning: Function parameter or member 'flags' not described in 'ndo_dflt_fdb_add'
net/core/rtnetlink.c:3718: warning: Function parameter or member 'ndm' not described in 'ndo_dflt_fdb_del'
net/core/rtnetlink.c:3718: warning: Function parameter or member 'tb' not described in 'ndo_dflt_fdb_del'
net/core/rtnetlink.c:3718: warning: Function parameter or member 'dev' not described in 'ndo_dflt_fdb_del'
net/core/rtnetlink.c:3718: warning: Function parameter or member 'addr' not described in 'ndo_dflt_fdb_del'
net/core/rtnetlink.c:3718: warning: Function parameter or member 'vid' not described in 'ndo_dflt_fdb_del'
net/core/rtnetlink.c:3861: warning: Function parameter or member 'skb' not described in 'ndo_dflt_fdb_dump'
net/core/rtnetlink.c:3861: warning: Function parameter or member 'cb' not described in 'ndo_dflt_fdb_dump'
net/core/rtnetlink.c:3861: warning: Function parameter or member 'filter_dev' not described in 'ndo_dflt_fdb_dump'
net/core/rtnetlink.c:3861: warning: Function parameter or member 'idx' not described in 'ndo_dflt_fdb_dump'
net/core/rtnetlink.c:3861: warning: Excess function parameter 'nlh' description in 'ndo_dflt_fdb_dump'

Cc: Hubert Sokolowski <hubert.sokolowski@intel.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Get rid of SWITCHDEV_ATTR_ID_PORT_PARENT_ID

Now that we have a dedicated NDO for getting a port's parent ID, get rid
of SWITCHDEV_ATTR_ID_PORT_PARENT_ID and convert all callers to use the
NDO exclusively. This is a preliminary change to getting rid of
switchdev_ops eventually.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Introduce ndo_get_port_parent_id()

In preparation for getting rid of switchdev_ops, create a dedicated NDO
operation for getting the port's parent identifier. There are
essentially two classes of drivers that need to implement getting the
port's parent ID which are VF/PF drivers with a built-in switch, and
pure switchdev drivers such as mlxsw, ocelot, dsa etc.

We introduce a helper function: dev_get_port_parent_id() which supports
recursion into the lower devices to obtain the first port's parent ID.

Convert the bridge, core and ipv4 multicast routing code to check for
such ndo_get_port_parent_id() and call the helper function when valid
before falling back to switchdev_port_attr_get(). This will allow us to
convert all relevant drivers in one go instead of having to implement
both switchdev_port_attr_get() and ndo_get_port_parent_id() operations,
then get rid of switchdev_port_attr_get().

Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: ifinfo: perform strict checks also for doit handler

Make RTM_GETLINK's doit handler use strict checks when
NETLINK_F_STRICT_CHK is set.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: stats: reject requests for unknown stats

In the spirit of strict checks reject requests of stats the kernel
does not support when NETLINK_F_STRICT_CHK is set.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: stats: validate attributes in get as well as dumps

Make sure NETLINK_GET_STRICT_CHK influences both GETSTATS doit
as well as the dump.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add extack argument to ndo_fdb_add()

Drivers may not be able to support certain FDB entries, and an error
code is insufficient to give clear hints as to the reasons of rejection.

In order to make it possible to communicate the rejection reason, extend
ndo_fdb_add() with an extack argument. Adapt the existing
implementations of ndo_fdb_add() to take the parameter (and ignore it).
Pass the extack parameter when invoking ndo_fdb_add() from rtnl_fdb_add().

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: address is mandatory for rtnl_fdb_get

We must have an address to lookup otherwise we'll derefence a null
pointer in the ndo_fdb_get callbacks.

CC: Roopa Prabhu <roopa@cumulusnetworks.com>
CC: David Ahern <dsa@cumulusnetworks.com>
Reported-by: syzbot+017b1f61c82a1c3e7efd@syzkaller.appspotmail.com
Fixes: 5b2f94b27622 ("net: rtnetlink: support for fdb get")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

neighbour: register rtnl doit handler

this patch registers neigh doit handler. The doit handler
returns a neigh entry given dst and dev. This is similar
to route and fdb doit (get) handlers. Also moves nda_policy
declaration from rtnetlink.c to neighbour.c

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnetlink: support for fdb get

This patch adds support for fdb get similar to
route get. arguments can be any of the following (similar to fdb add/del/dump):
[bridge, mac, vlan] or
[bridge_port, mac, vlan, flags=[NTF_MASTER]] or
[dev, mac, [vni|vlan], flags=[NTF_SELF]]

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: dev: Add extack argument to dev_set_mac_address()

A follow-up patch will add a notifier type NETDEV_PRE_CHANGEADDR, which
allows vetoing of MAC address changes. One prominent path to that
notification is through dev_set_mac_address(). Therefore give this
function an extack argument, so that it can be packed together with the
notification. Thus a textual reason for rejection (or a warning) can be
communicated back to the user.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: ndo_bridge_setlink: Add extack

Drivers may not be able to implement a VLAN addition or reconfiguration.
In those cases it's desirable to explain to the user that it was
rejected (and why).

To that end, add extack argument to ndo_bridge_setlink. Adapt all users
to that change.

Following patches will use the new argument in the bridge driver.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: dev: Add extack argument to __dev_change_flags()

In order to pass extack together with NETDEV_PRE_UP notifications, it's
necessary to route the extack to __dev_open() from diverse (possibly
indirect) callers. The last missing API is __dev_change_flags().

Therefore extend __dev_change_flags() with and extra extack argument and
update the two existing users.

Since the function declaration line is changed anyway, name the struct
net_device argument to placate checkpatch.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: dev: Add extack argument to dev_change_flags()

In order to pass extack together with NETDEV_PRE_UP notifications, it's
necessary to route the extack to __dev_open() from diverse (possibly
indirect) callers. One prominent API through which the notification is
invoked is dev_change_flags().

Therefore extend dev_change_flags() with and extra extack argument and
update all users. Most of the calls end up just encoding NULL, but
several sites (VLAN, ipvlan, VRF, rtnetlink) do have extack available.

Since the function declaration line is changed anyway, name the other
function arguments to placate checkpatch.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: ndo_dflt_fdb_dump() only work for ARPHRD_ETHER devices

kmsan was able to trigger a kernel-infoleak using a gre device [1]

nlmsg_populate_fdb_fill() has a hard coded assumption
that dev->addr_len is ETH_ALEN, as normally guaranteed
for ARPHRD_ETHER devices.

A similar issue was fixed recently in commit da71577545a5
("rtnetlink: Disallow FDB configuration for non-Ethernet device")

[1]
BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:143 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x4c0/0x2700 lib/iov_iter.c:576
CPU: 0 PID: 6697 Comm: syz-executor310 Not tainted 4.20.0-rc3+ #95
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x32d/0x480 lib/dump_stack.c:113
kmsan_report+0x12c/0x290 mm/kmsan/kmsan.c:683
kmsan_internal_check_memory+0x32a/0xa50 mm/kmsan/kmsan.c:743
kmsan_copy_to_user+0x78/0xd0 mm/kmsan/kmsan_hooks.c:634
copyout lib/iov_iter.c:143 [inline]
_copy_to_iter+0x4c0/0x2700 lib/iov_iter.c:576
copy_to_iter include/linux/uio.h:143 [inline]
skb_copy_datagram_iter+0x4e2/0x1070 net/core/datagram.c:431
skb_copy_datagram_msg include/linux/skbuff.h:3316 [inline]
netlink_recvmsg+0x6f9/0x19d0 net/netlink/af_netlink.c:1975
sock_recvmsg_nosec net/socket.c:794 [inline]
sock_recvmsg+0x1d1/0x230 net/socket.c:801
___sys_recvmsg+0x444/0xae0 net/socket.c:2278
__sys_recvmsg net/socket.c:2327 [inline]
__do_sys_recvmsg net/socket.c:2337 [inline]
__se_sys_recvmsg+0x2fa/0x450 net/socket.c:2334
__x64_sys_recvmsg+0x4a/0x70 net/socket.c:2334
do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x441119
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffc7f008a8 EFLAGS: 00000207 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000441119
RDX: 0000000000000040 RSI: 00000000200005c0 RDI: 0000000000000003
RBP: 00000000006cc018 R08: 0000000000000100 R09: 0000000000000100
R10: 0000000000000100 R11: 0000000000000207 R12: 0000000000402080
R13: 0000000000402110 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:246 [inline]
kmsan_save_stack mm/kmsan/kmsan.c:261 [inline]
kmsan_internal_chain_origin+0x13d/0x240 mm/kmsan/kmsan.c:469
kmsan_memcpy_memmove_metadata+0x1a9/0xf70 mm/kmsan/kmsan.c:344
kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:362
__msan_memcpy+0x61/0x70 mm/kmsan/kmsan_instr.c:162
__nla_put lib/nlattr.c:744 [inline]
nla_put+0x20a/0x2d0 lib/nlattr.c:802
nlmsg_populate_fdb_fill+0x444/0x810 net/core/rtnetlink.c:3466
nlmsg_populate_fdb net/core/rtnetlink.c:3775 [inline]
ndo_dflt_fdb_dump+0x73a/0x960 net/core/rtnetlink.c:3807
rtnl_fdb_dump+0x1318/0x1cb0 net/core/rtnetlink.c:3979
netlink_dump+0xc79/0x1c90 net/netlink/af_netlink.c:2244
__netlink_dump_start+0x10c4/0x11d0 net/netlink/af_netlink.c:2352
netlink_dump_start include/linux/netlink.h:216 [inline]
rtnetlink_rcv_msg+0x141b/0x1540 net/core/rtnetlink.c:4910
netlink_rcv_skb+0x394/0x640 net/netlink/af_netlink.c:2477
rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4965
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0x1699/0x1740 net/netlink/af_netlink.c:1336
netlink_sendmsg+0x13c7/0x1440 net/netlink/af_netlink.c:1917
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg net/socket.c:631 [inline]
___sys_sendmsg+0xe3b/0x1240 net/socket.c:2116
__sys_sendmsg net/socket.c:2154 [inline]
__do_sys_sendmsg net/socket.c:2163 [inline]
__se_sys_sendmsg+0x305/0x460 net/socket.c:2161
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:246 [inline]
kmsan_internal_poison_shadow+0x6d/0x130 mm/kmsan/kmsan.c:170
kmsan_kmalloc+0xa1/0x100 mm/kmsan/kmsan_hooks.c:186
__kmalloc+0x14c/0x4d0 mm/slub.c:3825
kmalloc include/linux/slab.h:551 [inline]
__hw_addr_create_ex net/core/dev_addr_lists.c:34 [inline]
__hw_addr_add_ex net/core/dev_addr_lists.c:80 [inline]
__dev_mc_add+0x357/0x8a0 net/core/dev_addr_lists.c:670
dev_mc_add+0x6d/0x80 net/core/dev_addr_lists.c:687
ip_mc_filter_add net/ipv4/igmp.c:1128 [inline]
igmp_group_added+0x4d4/0xb80 net/ipv4/igmp.c:1311
__ip_mc_inc_group+0xea9/0xf70 net/ipv4/igmp.c:1444
ip_mc_inc_group net/ipv4/igmp.c:1453 [inline]
ip_mc_up+0x1c3/0x400 net/ipv4/igmp.c:1775
inetdev_event+0x1d03/0x1d80 net/ipv4/devinet.c:1522
notifier_call_chain kernel/notifier.c:93 [inline]
__raw_notifier_call_chain kernel/notifier.c:394 [inline]
raw_notifier_call_chain+0x13d/0x240 kernel/notifier.c:401
__dev_notify_flags+0x3da/0x860 net/core/dev.c:1733
dev_change_flags+0x1ac/0x230 net/core/dev.c:7569
do_setlink+0x165f/0x5ea0 net/core/rtnetlink.c:2492
rtnl_newlink+0x2ad7/0x35a0 net/core/rtnetlink.c:3111
rtnetlink_rcv_msg+0x1148/0x1540 net/core/rtnetlink.c:4947
netlink_rcv_skb+0x394/0x640 net/netlink/af_netlink.c:2477
rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4965
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0x1699/0x1740 net/netlink/af_netlink.c:1336
netlink_sendmsg+0x13c7/0x1440 net/netlink/af_netlink.c:1917
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg net/socket.c:631 [inline]
___sys_sendmsg+0xe3b/0x1240 net/socket.c:2116
__sys_sendmsg net/socket.c:2154 [inline]
__do_sys_sendmsg net/socket.c:2163 [inline]
__se_sys_sendmsg+0x305/0x460 net/socket.c:2161
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7

Bytes 36-37 of 105 are uninitialized
Memory access of size 105 starts at ffff88819686c000
Data copied to user address 0000000020000380

Fixes: d83b06036048 ("net: add fdb generic dump routine")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Ido Schimmel <idosch@mellanox.com>
Cc: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: avoid frame size warning in rtnl_newlink()

Standard kernel compilation produces the following warning:

net/core/rtnetlink.c: In function ‘rtnl_newlink’:
net/core/rtnetlink.c:3232:1: warning: the frame size of 1288 bytes is larger than 1024 bytes [-Wframe-larger-than=]
}
^

This should not really be an issue, as rtnl_newlink() stack is
generally quite shallow.

Fix the warning by allocating attributes with kmalloc() in a wrapper
and passing it down to rtnl_newlink(), avoiding complexities on error
paths.

Alternatively we could kmalloc() some structure within rtnl_newlink(),
slave attributes look like a good candidate. In practice it adds to
already rather high complexity and length of the function.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: remove a level of indentation in rtnl_newlink()

rtnl_newlink() used to create VLAs based on link kind. Since
commit ccf8dbcd062a ("rtnetlink: Remove VLA usage") statically
sized array is created on the stack, so there is no more use
for a separate code block that used to be the VLA's live range.

While at it christmas tree the variables. Note that there is
a goto-based retry so to be on the safe side the variables can
no longer be initialized in place. It doesn't seem to matter,
logically, but why make the code harder to read..

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: bridge: add support for user-controlled bool options

We have been adding many new bridge options, a big number of which are
boolean but still take up netlink attribute ids and waste space in the skb.
Recently we discussed learning from link-local packets[1] and decided
yet another new boolean option will be needed, thus introducing this API
to save some bridge nl space.
The API supports changing the value of multiple boolean options at once
via the br_boolopt_multi struct which has an optmask (which options to
set, bit per opt) and optval (options' new values). Future boolean
options will only be added to the br_boolopt_id enum and then will have
to be handled in br_boolopt_toggle/get. The API will automatically
add the ability to change and export them via netlink, sysfs can use the
single boolopt function versions to do the same. The behaviour with
failing/succeeding is the same as with normal netlink option changing.

If an option requires mapping to internal kernel flag or needs special
configuration to be enabled then it should be handled in
br_boolopt_toggle. It should also be able to retrieve an option's current
state via br_boolopt_get.

v2: WARN_ON() on unsupported option as that shouldn't be possible and
also will help catch people who add new options without handling
them for both set and get. Pass down extack so if an option desires
it could set it on error and be more user-friendly.

[1] https://www.spinics.net/lists/netdev/msg532698.html

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Add more extack messages to rtnl_newlink

Add extack arg to the nla_parse_nested calls in rtnl_newlink, and
add messages for unknown device type and link network namespace id.
In particular, it improves the failure message when the wrong link
type is used. From
$ ip li add bond1 type bonding
RTNETLINK answers: Operation not supported
to
$ ip li add bond1 type bonding
Error: Unknown device type.

(The module name is bonding but the link type is bond.)

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add extack argument to rtnl_create_link

Add extack arg to rtnl_create_link and add messages for invalid
number of Tx or Rx queues.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: restore handling of dumpit return value in rtnl_dump_all()

For non-zero return from dumpit() we should break the loop
in rtnl_dump_all() and return the result. Otherwise, e.g.,
we could get the memory leak in inet6_dump_fib() [1]. The
pointer to the allocated struct fib6_walker there (saved
in cb->args) can be lost, reset on the next iteration.

Fix it by partially restoring the previous behavior before
commit c63586dc9b3e ("net: rtnl_dump_all needs to propagate
error from dumpit function"). The returned error from
dumpit() is still passed further.

[1]:
unreferenced object 0xffff88001322a200 (size 96):
comm "sshd", pid 1484, jiffies 4296032768 (age 1432.542s)
hex dump (first 32 bytes):
00 01 00 00 00 00 ad de 00 02 00 00 00 00 ad de ................
18 09 41 36 00 88 ff ff 18 09 41 36 00 88 ff ff ..A6......A6....
backtrace:
[<0000000095846b39>] kmem_cache_alloc_trace+0x151/0x220
[<000000007d12709f>] inet6_dump_fib+0x68d/0x940
[<000000002775a316>] rtnl_dump_all+0x1d9/0x2d0
[<00000000d7cd302b>] netlink_dump+0x945/0x11a0
[<000000002f43485f>] __netlink_dump_start+0x55d/0x800
[<00000000f76bbeec>] rtnetlink_rcv_msg+0x4fa/0xa00
[<000000009b5761f3>] netlink_rcv_skb+0x29c/0x420
[<0000000087a1dae1>] rtnetlink_rcv+0x15/0x20
[<00000000691b703b>] netlink_unicast+0x4e3/0x6c0
[<00000000b5be0204>] netlink_sendmsg+0x7f2/0xba0
[<0000000096d2aa60>] sock_sendmsg+0xba/0xf0
[<000000008c1b786f>] __sys_sendto+0x1e4/0x330
[<0000000019587b3f>] __x64_sys_sendto+0xe1/0x1a0
[<00000000071f4d56>] do_syscall_64+0x9f/0x300
[<000000002737577f>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[<0000000057587684>] 0xffffffffffffffff

Fixes: c63586dc9b3e ("net: rtnl_dump_all needs to propagate error from dumpit function")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Disallow FDB configuration for non-Ethernet device

When an FDB entry is configured, the address is validated to have the
length of an Ethernet address, but the device for which the address is
configured can be of any type.

The above can result in the use of uninitialized memory when the address
is later compared against existing addresses since 'dev->addr_len' is
used and it may be greater than ETH_ALEN, as with ip6tnl devices.

Fix this by making sure that FDB entries are only configured for
Ethernet devices.

BUG: KMSAN: uninit-value in memcmp+0x11d/0x180 lib/string.c:863
CPU: 1 PID: 4318 Comm: syz-executor998 Not tainted 4.19.0-rc3+ #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x14b/0x190 lib/dump_stack.c:113
kmsan_report+0x183/0x2b0 mm/kmsan/kmsan.c:956
__msan_warning+0x70/0xc0 mm/kmsan/kmsan_instr.c:645
memcmp+0x11d/0x180 lib/string.c:863
dev_uc_add_excl+0x165/0x7b0 net/core/dev_addr_lists.c:464
ndo_dflt_fdb_add net/core/rtnetlink.c:3463 [inline]
rtnl_fdb_add+0x1081/0x1270 net/core/rtnetlink.c:3558
rtnetlink_rcv_msg+0xa0b/0x1530 net/core/rtnetlink.c:4715
netlink_rcv_skb+0x36e/0x5f0 net/netlink/af_netlink.c:2454
rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4733
netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
netlink_unicast+0x1638/0x1720 net/netlink/af_netlink.c:1343
netlink_sendmsg+0x1205/0x1290 net/netlink/af_netlink.c:1908
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg net/socket.c:631 [inline]
___sys_sendmsg+0xe70/0x1290 net/socket.c:2114
__sys_sendmsg net/socket.c:2152 [inline]
__do_sys_sendmsg net/socket.c:2161 [inline]
__se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159
do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x440ee9
Code: e8 cc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff6a93b518 EFLAGS: 00000213 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440ee9
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000213 R12: 000000000000b4b0
R13: 0000000000401ec0 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:256 [inline]
kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:181
kmsan_kmalloc+0x98/0x100 mm/kmsan/kmsan_hooks.c:91
kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan_hooks.c:100
slab_post_alloc_hook mm/slab.h:446 [inline]
slab_alloc_node mm/slub.c:2718 [inline]
__kmalloc_node_track_caller+0x9e7/0x1160 mm/slub.c:4351
__kmalloc_reserve net/core/skbuff.c:138 [inline]
__alloc_skb+0x2f5/0x9e0 net/core/skbuff.c:206
alloc_skb include/linux/skbuff.h:996 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1189 [inline]
netlink_sendmsg+0xb49/0x1290 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:621 [inline]
sock_sendmsg net/socket.c:631 [inline]
___sys_sendmsg+0xe70/0x1290 net/socket.c:2114
__sys_sendmsg net/socket.c:2152 [inline]
__do_sys_sendmsg net/socket.c:2161 [inline]
__se_sys_sendmsg+0x2a3/0x3d0 net/socket.c:2159
__x64_sys_sendmsg+0x4a/0x70 net/socket.c:2159
do_syscall_64+0xb8/0x100 arch/x86/entry/common.c:291
entry_SYSCALL_64_after_hwframe+0x63/0xe7

v2:
* Make error message more specific (David)

Fixes: 090096bf3db1 ("net: generic fdb support for drivers without ndo_fdb_<op>")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-and-tested-by: syzbot+3a288d5f5530b901310e@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+d53ab4e92a1db04110ff@syzkaller.appspotmail.com
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnl_dump_all needs to propagate error from dumpit function

If an address, route or netconf dump request is sent for AF_UNSPEC, then
rtnl_dump_all is used to do the dump across all address families. If one
of the dumpit functions fails (e.g., invalid attributes in the dump
request) then rtnl_dump_all needs to propagate that error so the user
gets an appropriate response instead of just getting no data.

Fixes: effe67926624 ("net: Enable kernel side filtering of route dumps")
Fixes: 5fcd266a9f64 ("net/ipv4: Add support for dumping addresses for a specific device")
Fixes: 6371a71f3a3b ("net/ipv6: Add support for dumping addresses for a specific device")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: bridge: add support for per-port vlan stats

This patch adds an option to have per-port vlan stats instead of the
default global stats. The option can be set only when there are no port
vlans in the bridge since we need to allocate the stats if it is set
when vlans are being added to ports (and respectively free them
when being deleted). Also bump RTNL_MAX_TYPE as the bridge is the
largest user of options. The current stats design allows us to add
these without any changes to the fast-path, it all comes down to
the per-vlan stats pointer which, if this option is enabled, will
be allocated for each port vlan instead of using the global bridge-wide
one.

CC: bridge@lists.linux-foundation.org
CC: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Update comment in rtnl_stats_dump regarding strict data checking

The NLM_F_DUMP_PROPER_HDR netlink flag was replaced by a setsockopt.
Update the comment in rtnl_stats_dump.

Fixes: 841891ec0c65 ("rtnetlink: Update rtnl_stats_dump for strict data checking")
Reported-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Move ifm in valid_fdb_dump_legacy to closer to use

Move setting of local variable ifm to after the message parsing in
valid_fdb_dump_legacy. Avoid potential future use of unchecked variable.

Fixes: 8dfbda19a21b ("rtnetlink: Move input checking for rtnl_fdb_dump to helper")
Reported-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Update rtnl_fdb_dump for strict data checking

Update rtnl_fdb_dump for strict data checking. If the flag is set,
the dump request is expected to have an ndmsg struct as the header
potentially followed by one or more attributes. Any data passed in the
header or as an attribute is taken as a request to influence the data
returned. Only values supported by the dump handler are allowed to be
non-0 or set in the request. At the moment only the NDA_IFINDEX and
NDA_MASTER attributes are supported.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Move input checking for rtnl_fdb_dump to helper

Move the existing input checking for rtnl_fdb_dump into a helper,
valid_fdb_dump_legacy. This function will retain the current
logic that works around the 2 headers that userspace has been
allowed to send up to this point.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Update rtnl_stats_dump for strict data checking

Update rtnl_stats_dump for strict data checking. If the flag is set,
the dump request is expected to have an if_stats_msg struct as the header.
All elements of the struct are expected to be 0 except filter_mask which
must be non-0 (legacy behavior). No attributes are supported.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Update rtnl_bridge_getlink for strict data checking

Update rtnl_bridge_getlink for strict data checking. If the flag is set,
the dump request is expected to have an ifinfomsg struct as the header
potentially followed by one or more attributes. Any data passed in the
header or as an attribute is taken as a request to influence the data
returned. Only values supported by the dump handler are allowed to be
non-0 or set in the request. At the moment only the IFLA_EXT_MASK
attribute is supported.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Update rtnl_dump_ifinfo for strict data checking

Update rtnl_dump_ifinfo for strict data checking. If the flag is set,
the dump request is expected to have an ifinfomsg struct as the header
potentially followed by one or more attributes. Any data passed in the
header or as an attribute is taken as a request to influence the data
returned. Only values supported by the dump handler are allowed to be
non-0 or set in the request. At the moment only the IFA_TARGET_NETNSID,
IFLA_EXT_MASK, IFLA_MASTER, and IFLA_LINKINFO attributes are supported.

Existing code does not fail the dump if nlmsg_parse fails. That behavior
is kept for non-strict checking.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add extack to nlmsg_parse

Make sure extack is passed to nlmsg_parse where easy to do so.
Most of these are dump handlers and leveraging the extack in
the netlink_callback.

Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: fix rtnl_fdb_dump() for ndmsg header

Currently, rtnl_fdb_dump() assumes the family header is 'struct ifinfomsg',
which is not always true -- 'struct ndmsg' is used by iproute2 ('ip neigh').

The problem is, the function bails out early if nlmsg_parse() fails, which
does occur for iproute2 usage of 'struct ndmsg' because the payload length
is shorter than the family header alone (as 'struct ifinfomsg' is assumed).

This breaks backward compatibility with userspace -- nothing is sent back.

Some examples with iproute2 and netlink library for go [1]:

1) $ bridge fdb show
33:33:00:00:00:01 dev ens3 self permanent
01:00:5e:00:00:01 dev ens3 self permanent
33:33:ff:15:98:30 dev ens3 self permanent

This one works, as it uses 'struct ifinfomsg'.

fdb_show() @ iproute2/bridge/fdb.c
"""
.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifinfomsg)),
...
if (rtnl_dump_request(&rth, RTM_GETNEIGH, [...]
"""

2) $ ip --family bridge neigh
RTNETLINK answers: Invalid argument
Dump terminated

This one fails, as it uses 'struct ndmsg'.

do_show_or_flush() @ iproute2/ip/ipneigh.c
"""
.n.nlmsg_type = RTM_GETNEIGH,
.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ndmsg)),
"""

3) $ ./neighlist
< no output >

This one fails, as it uses 'struct ndmsg'-based.

neighList() @ netlink/neigh_linux.go
"""
req := h.newNetlinkRequest(unix.RTM_GETNEIGH, [...]
msg := Ndmsg{
"""

The actual breakage was introduced by commit 0ff50e83b512 ("net: rtnetlink:
bail out from rtnl_fdb_dump() on parse error"), because nlmsg_parse() fails
if the payload length (with the _actual_ family header) is less than the
family header length alone (which is assumed, in parameter 'hdrlen').
This is true in the examples above with struct ndmsg, with size and payload
length shorter than struct ifinfomsg.

However, that commit just intends to fix something under the assumption the
family header is indeed an 'struct ifinfomsg' - by preventing access to the
payload as such (via 'ifm' pointer) if the payload length is not sufficient
to actually contain it.

The assumption was introduced by commit 5e6d24358799 ("bridge: netlink dump
interface at par with brctl"), to support iproute2's 'bridge fdb' command
(not 'ip neigh') which indeed uses 'struct ifinfomsg', thus is not broken.

So, in order to unbreak the 'struct ndmsg' family headers and still allow
'struct ifinfomsg' to continue to work, check for the known message sizes
used with 'struct ndmsg' in iproute2 (with zero or one attribute which is
not used in this function anyway) then do not parse the data as ifinfomsg.

Same examples with this patch applied (or revert/before the original fix):

$ bridge fdb show
33:33:00:00:00:01 dev ens3 self permanent
01:00:5e:00:00:01 dev ens3 self permanent
33:33:ff:15:98:30 dev ens3 self permanent

$ ip --family bridge neigh
dev ens3 lladdr 33:33:00:00:00:01 PERMANENT
dev ens3 lladdr 01:00:5e:00:00:01 PERMANENT
dev ens3 lladdr 33:33:ff:15:98:30 PERMANENT

$ ./neighlist
netlink.Neigh{LinkIndex:2, Family:7, State:128, Type:0, Flags:2, IP:net.IP(nil), HardwareAddr:net.HardwareAddr{0x33, 0x33, 0x0, 0x0, 0x0, 0x1}, LLIPAddr:net.IP(nil), Vlan:0, VNI:0}
netlink.Neigh{LinkIndex:2, Family:7, State:128, Type:0, Flags:2, IP:net.IP(nil), HardwareAddr:net.HardwareAddr{0x1, 0x0, 0x5e, 0x0, 0x0, 0x1}, LLIPAddr:net.IP(nil), Vlan:0, VNI:0}
netlink.Neigh{LinkIndex:2, Family:7, State:128, Type:0, Flags:2, IP:net.IP(nil), HardwareAddr:net.HardwareAddr{0x33, 0x33, 0xff, 0x15, 0x98, 0x30}, LLIPAddr:net.IP(nil), Vlan:0, VNI:0}

Tested on mainline (v4.19-rc6) and net-next (3bd09b05b068).

References:

[1] netlink library for go (test-case)
https://github.com/vishvananda/netlink

$ cat ~/go/src/neighlist/main.go
package main
import ("fmt"; "syscall"; "github.com/vishvananda/netlink")
func main() {
neighs, _ := netlink.NeighList(0, syscall.AF_BRIDGE)
for _, neigh := range neighs { fmt.Printf("%#v\n", neigh) }
}

$ export GOPATH=~/go
$ go get github.com/vishvananda/netlink
$ go build neighlist
$ ~/go/src/neighlist/neighlist

Thanks to David Ahern for suggestions to improve this patch.

Fixes: 0ff50e83b512 ("net: rtnetlink: bail out from rtnl_fdb_dump() on parse error")
Fixes: 5e6d24358799 ("bridge: netlink dump interface at par with brctl")
Reported-by: Aidan Obley <aobley@pivotal.io>
Signed-off-by: Mauricio Faria de Oliveira <mfo@canonical.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnl: limit IFLA_NUM_TX_QUEUES and IFLA_NUM_RX_QUEUES to 4096

We have an impressive number of syzkaller bugs that are linked
to the fact that syzbot was able to create a networking device
with millions of TX (or RX) queues.

Let's limit the number of RX/TX queues to 4096, this really should
cover all known cases.

A separate patch will add various cond_resched() in the loops
handling sysfs entries at device creation and dismantle.

Tested:

lpaa6:~# ip link add gre-4097 numtxqueues 4097 numrxqueues 4097 type ip6gretap
RTNETLINK answers: Invalid argument

lpaa6:~# time ip link add gre-4096 numtxqueues 4096 numrxqueues 4096 type ip6gretap

real 0m0.180s
user 0m0.000s
sys 0m0.107s

Fixes: 76ff5cc91935 ("rtnl: allow to specify number of rx and tx queues on device creation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Fail dump if target netnsid is invalid

Link dumps can return results from a target namespace. If the namespace id
is invalid, then the dump request should fail if get_target_net fails
rather than continuing with a dump of the current namespace.

Fixes: 79e1ad148c844 ("rtnetlink: use netnsid to query interface")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: netlink: add helper refcount dec and lock function

Rtnl lock is encapsulated in netlink and cannot be accessed by other
modules directly. This means that reference counted objects that rely on
rtnl lock cannot use it with refcounter helper function that atomically
releases decrements reference and obtains mutex.

This patch implements simple wrapper function around refcount_dec_and_lock
that obtains rtnl lock if reference counter value reached 0.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnl_configure_link: fix dev flags changes arg to __dev_notify_flags

This fix addresses https://bugzilla.kernel.org/show_bug.cgi?id=201071

Commit 5025f7f7d506 wrongly relied on __dev_change_flags to notify users of
dev flag changes in the case when dev->rtnl_link_state = RTNL_LINK_INITIALIZED.
Fix it by indicating flag changes explicitly to __dev_notify_flags.

Fixes: 5025f7f7d506 ("rtnetlink: add rtnl_link_state check in rtnl_configure_link")
Reported-By: Liam mcbirnie <liam.mcbirnie@boeing.com>
Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: s/IFLA_IF_NETNSID/IFLA_TARGET_NETNSID/g

IFLA_TARGET_NETNSID is the new alias for IFLA_IF_NETNSID. This commit
replaces all occurrences of IFLA_IF_NETNSID with the new alias to
indicate that this identifier is the preferred one.

Signed-off-by: Christian Brauner <christian@brauner.io>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Cc: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: move type calculation out of loop

I don't see how the type - which is one of
RTM_{GETADDR,GETROUTE,GETNETCONF} - can change. So do the message type
calculation once before entering the for loop.

Signed-off-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: add rtnl_get_net_ns_capable()

get_target_net() will be used in follow-up patches in ipv{4,6} codepaths to
retrieve network namespaces based on network namespace identifiers. So
remove the static declaration and export in the rtnetlink header. Also,
rename it to rtnl_get_net_ns_capable() to make it obvious what this
function is doing.
Export rtnl_get_net_ns_capable() so it can be used when ipv6 is built as
a module.

Signed-off-by: Christian Brauner <christian@brauner.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rtnl: return early from rtnl_unregister_all when protocol isn't registered

rtnl_unregister_all(PF_INET6) gets called from inet6_init in cases when
no handler has been registered for PF_INET6 yet, for example if
ip6_mr_init() fails. Abort and avoid a NULL pointer deref in that case.

Example of panic (triggered by faking a failure of
register_pernet_subsys):

general protection fault: 0000 [#1] PREEMPT SMP KASAN PTI
[...]
RIP: 0010:rtnl_unregister_all+0x17e/0x2a0
[...]
Call Trace:
? rtnetlink_net_init+0x250/0x250
? sock_unregister+0x103/0x160
? kernel_getsockopt+0x200/0x200
inet6_init+0x197/0x20d

Fixes: e2fddf5e96df ("[IPV6]: Make af_inet6 to check ip6_route_init return value.")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: report invalid mtu value via netlink extack

If an invalid MTU value is set through rtnetlink return extra error
information instead of putting message in kernel log. For other cases
where there is no visible API, keep the error report in the log.

Example:
# ip li set dev enp12s0 mtu 10000
Error: mtu greater than device maximum.

# ifconfig enp12s0 mtu 10000
SIOCSIFMTU: Invalid argument
# dmesg | tail -1
[ 2047.795467] enp12s0: mtu greater than device maximum

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: report min and max mtu network device settings

Report the minimum and maximum MTU allowed on a device
via netlink so that it can be displayed by tools like
ip link.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: add rtnl_link_state check in rtnl_configure_link

rtnl_configure_link sets dev->rtnl_link_state to
RTNL_LINK_INITIALIZED and unconditionally calls
__dev_notify_flags to notify user-space of dev flags.

current call sequence for rtnl_configure_link
rtnetlink_newlink
rtnl_link_ops->newlink
rtnl_configure_link (unconditionally notifies userspace of
default and new dev flags)

If a newlink handler wants to call rtnl_configure_link
early, we will end up with duplicate notifications to
user-space.

This patch fixes rtnl_configure_link to check rtnl_link_state
and call __dev_notify_flags with gchanges = 0 if already
RTNL_LINK_INITIALIZED.

Later in the series, this patch will help the following sequence
where a driver implementing newlink can call rtnl_configure_link
to initialize the link early.

makes the following call sequence work:
rtnetlink_newlink
rtnl_link_ops->newlink (vxlan) -> rtnl_configure_link (initializes
link and notifies
user-space of default
dev flags)
rtnl_configure_link (updates dev flags if requested by user ifm
and notifies user-space of new dev flags)

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

xdp: fix uninitialized 'err' variable

Smatch caught an uninitialized variable error which GCC seems
to miss.

Fixes: a25717d2b604 ("xdp: support simultaneous driver and hw XDP attachment")
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

xdp: support simultaneous driver and hw XDP attachment

Split the query of HW-attached program from the software one.
Introduce new .ndo_bpf command to query HW-attached program.
This will allow drivers to install different programs in HW
and SW at the same time. Netlink can now also carry multiple
programs on dump (in which case mode will be set to
XDP_ATTACHED_MULTI and user has to check per-attachment point
attributes, IFLA_XDP_PROG_ID will not be present). We reuse
IFLA_XDP_PROG_ID skb space for second mode, so rtnl_xdp_size()
doesn't need to be updated.

Note that the installation side is still not there, since all
drivers currently reject installing more than one program at
the time.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

xdp: don't make drivers report attachment mode

prog_attached of struct netdev_bpf should have been superseded
by simply setting prog_id long time ago, but we kept it around
to allow offloading drivers to communicate attachment mode (drv
vs hw). Subsequently drivers were also allowed to report back
attachment flags (prog_flags), and since nowadays only programs
attached will XDP_FLAGS_HW_MODE can get offloaded, we can tell
the attachment mode from the flags driver reports. Remove
prog_attached member.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

xdp: add per mode attributes for attached programs

In preparation for support of simultaneous driver and hardware XDP
support add per-mode attributes. The catch-all IFLA_XDP_PROG_ID
will still be reported, but user space can now also access the
program ID in a new IFLA_XDP_<mode>_PROG_ID attribute.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

rtnetlink: add rtnl_link_state check in rtnl_configure_link

rtnl_configure_link sets dev->rtnl_link_state to
RTNL_LINK_INITIALIZED and unconditionally calls
__dev_notify_flags to notify user-space of dev flags.

current call sequence for rtnl_configure_link
rtnetlink_newlink
rtnl_link_ops->newlink
rtnl_configure_link (unconditionally notifies userspace of
default and new dev flags)

If a newlink handler wants to call rtnl_configure_link
early, we will end up with duplicate notifications to
user-space.

This patch fixes rtnl_configure_link to check rtnl_link_state
and call __dev_notify_flags with gchanges = 0 if already
RTNL_LINK_INITIALIZED.

Later in the series, this patch will help the following sequence
where a driver implementing newlink can call rtnl_configure_link
to initialize the link early.

makes the following call sequence work:
rtnetlink_newlink
rtnl_link_ops->newlink (vxlan) -> rtnl_configure_link (initializes
link and notifies
user-space of default
dev flags)
rtnl_configure_link (updates dev flags if requested by user ifm
and notifies user-space of new dev flags)

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: validate attributes in do_setlink()

It seems that rtnl_group_changelink() can call do_setlink
while a prior call to validate_linkmsg(dev = NULL, ...) could
not validate IFLA_ADDRESS / IFLA_BROADCAST

Make sure do_setlink() calls validate_linkmsg() instead
of letting its callers having this responsibility.

With help from Dmitry Vyukov, thanks a lot !

BUG: KMSAN: uninit-value in is_valid_ether_addr include/linux/etherdevice.h:199 [inline]
BUG: KMSAN: uninit-value in eth_prepare_mac_addr_change net/ethernet/eth.c:275 [inline]
BUG: KMSAN: uninit-value in eth_mac_addr+0x203/0x2b0 net/ethernet/eth.c:308
CPU: 1 PID: 8695 Comm: syz-executor3 Not tainted 4.17.0-rc5+ #103
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:113
kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084
__msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:686
is_valid_ether_addr include/linux/etherdevice.h:199 [inline]
eth_prepare_mac_addr_change net/ethernet/eth.c:275 [inline]
eth_mac_addr+0x203/0x2b0 net/ethernet/eth.c:308
dev_set_mac_address+0x261/0x530 net/core/dev.c:7157
do_setlink+0xbc3/0x5fc0 net/core/rtnetlink.c:2317
rtnl_group_changelink net/core/rtnetlink.c:2824 [inline]
rtnl_newlink+0x1fe9/0x37a0 net/core/rtnetlink.c:2976
rtnetlink_rcv_msg+0xa32/0x1560 net/core/rtnetlink.c:4646
netlink_rcv_skb+0x378/0x600 net/netlink/af_netlink.c:2448
rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4664
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0x1678/0x1750 net/netlink/af_netlink.c:1336
netlink_sendmsg+0x104f/0x1350 net/netlink/af_netlink.c:1901
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg net/socket.c:639 [inline]
___sys_sendmsg+0xec0/0x1310 net/socket.c:2117
__sys_sendmsg net/socket.c:2155 [inline]
__do_sys_sendmsg net/socket.c:2164 [inline]
__se_sys_sendmsg net/socket.c:2162 [inline]
__x64_sys_sendmsg+0x331/0x460 net/socket.c:2162
do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455a09
RSP: 002b:00007fc07480ec68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc07480f6d4 RCX: 0000000000455a09
RDX: 0000000000000000 RSI: 00000000200003c0 RDI: 0000000000000014
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000005d0 R14: 00000000006fdc20 R15: 0000000000000000

Uninit was stored to memory at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
kmsan_save_stack mm/kmsan/kmsan.c:294 [inline]
kmsan_internal_chain_origin+0x12b/0x210 mm/kmsan/kmsan.c:685
kmsan_memcpy_origins+0x11d/0x170 mm/kmsan/kmsan.c:527
__msan_memcpy+0x109/0x160 mm/kmsan/kmsan_instr.c:478
do_setlink+0xb84/0x5fc0 net/core/rtnetlink.c:2315
rtnl_group_changelink net/core/rtnetlink.c:2824 [inline]
rtnl_newlink+0x1fe9/0x37a0 net/core/rtnetlink.c:2976
rtnetlink_rcv_msg+0xa32/0x1560 net/core/rtnetlink.c:4646
netlink_rcv_skb+0x378/0x600 net/netlink/af_netlink.c:2448
rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4664
netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
netlink_unicast+0x1678/0x1750 net/netlink/af_netlink.c:1336
netlink_sendmsg+0x104f/0x1350 net/netlink/af_netlink.c:1901
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg net/socket.c:639 [inline]
___sys_sendmsg+0xec0/0x1310 net/socket.c:2117
__sys_sendmsg net/socket.c:2155 [inline]
__do_sys_sendmsg net/socket.c:2164 [inline]
__se_sys_sendmsg net/socket.c:2162 [inline]
__x64_sys_sendmsg+0x331/0x460 net/socket.c:2162
do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189
kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315
kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:322
slab_post_alloc_hook mm/slab.h:446 [inline]
slab_alloc_node mm/slub.c:2753 [inline]
__kmalloc_node_track_caller+0xb32/0x11b0 mm/slub.c:4395
__kmalloc_reserve net/core/skbuff.c:138 [inline]
__alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
alloc_skb include/linux/skbuff.h:988 [inline]
netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
netlink_sendmsg+0x76e/0x1350 net/netlink/af_netlink.c:1876
sock_sendmsg_nosec net/socket.c:629 [inline]
sock_sendmsg net/socket.c:639 [inline]
___sys_sendmsg+0xec0/0x1310 net/socket.c:2117
__sys_sendmsg net/socket.c:2155 [inline]
__do_sys_sendmsg net/socket.c:2164 [inline]
__se_sys_sendmsg net/socket.c:2162 [inline]
__x64_sys_sendmsg+0x331/0x460 net/socket.c:2162
do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: e7ed828f10bd ("netlink: support setting devgroup parameters")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Fix null-ptr-deref in rtnl_newlink

In rtnl_newlink(), NULL check is performed on m_ops however member of
ops is accessed. Fixed by accessing member of m_ops instead of ops.

[ 345.432629] BUG: KASAN: null-ptr-deref in rtnl_newlink+0x400/0x1110
[ 345.432629] Read of size 4 at addr 0000000000000088 by task ip/986
[ 345.432629]
[ 345.432629] CPU: 1 PID: 986 Comm: ip Not tainted 4.17.0-rc6+ #9
[ 345.432629] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[ 345.432629] Call Trace:
[ 345.432629] dump_stack+0xc6/0x150
[ 345.432629] ? dump_stack_print_info.cold.0+0x1b/0x1b
[ 345.432629] ? kasan_report+0xb4/0x410
[ 345.432629] kasan_report.cold.4+0x8f/0x91
[ 345.432629] ? rtnl_newlink+0x400/0x1110
[ 345.432629] rtnl_newlink+0x400/0x1110
[...]

Fixes: ccf8dbcd062a ("rtnetlink: Remove VLA usage")
Signed-off-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Tested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: Remove VLA usage

In the quest to remove all stack VLA usage from the kernel[1], this
allocates the maximum size expected for all possible types and adds
sanity-checks at both registration and usage to make sure nothing gets
out of sync. This matches the proposed VLA solution for nfnetlink[2]. The
values chosen here were based on finding assignments for .maxtype and
.slave_maxtype and manually counting the enums:

slave_maxtype (max 33):
IFLA_BRPORT_MAX 33
IFLA_BOND_SLAVE_MAX 9

maxtype (max 45):
IFLA_BOND_MAX 28
IFLA_BR_MAX 45
__IFLA_CAIF_HSI_MAX 8
IFLA_CAIF_MAX 4
IFLA_CAN_MAX 16
IFLA_GENEVE_MAX 12
IFLA_GRE_MAX 25
IFLA_GTP_MAX 5
IFLA_HSR_MAX 7
IFLA_IPOIB_MAX 4
IFLA_IPTUN_MAX 21
IFLA_IPVLAN_MAX 3
IFLA_MACSEC_MAX 15
IFLA_MACVLAN_MAX 7
IFLA_PPP_MAX 2
__IFLA_RMNET_MAX 4
IFLA_VLAN_MAX 6
IFLA_VRF_MAX 2
IFLA_VTI_MAX 7
IFLA_VXLAN_MAX 28
VETH_INFO_MAX 2
VXCAN_INFO_MAX 2

This additionally changes maxtype and slave_maxtype fields to unsigned,
since they're only ever using positive values.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com
[2] https://patchwork.kernel.org/patch/10439647/

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Handle null dst in rtnl_put_cacheinfo

Need to keep expires time for IPv6 routes in a dump of FIB entries.
Update rtnl_put_cacheinfo to allow dst to be NULL in which case
rta_cacheinfo will only contain non-dst data.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Do not take net_rwsem in __rtnl_link_unregister()

This function calls call_netdevice_notifier(), which also
may take net_rwsem. So, we can't use net_rwsem here.

This patch makes callers of this functions take pernet_ops_rwsem,
like register_netdevice_notifier() does. This will protect
the modifications of net_namespace_list, and allows notifiers
to take it (they won't have to care about context).

Since __rtnl_link_unregister() is used on module load
and unload (which are not frequent operations), this looks
for me better, than make all call_netdevice_notifier()
always executing in "protected net_namespace_list" context.

Also, this fixes the problem we had a deal in 328fbe747ad4
"Close race between {un, }register_netdevice_notifier and ...",
and guarantees __rtnl_link_unregister() does not skip
exitting net.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Introduce net_rwsem to protect net_namespace_list

rtnl_lock() is used everywhere, and contention is very high.
When someone wants to iterate over alive net namespaces,
he/she has no a possibility to do that without exclusive lock.
But the exclusive rtnl_lock() in such places is overkill,
and it just increases the contention. Yes, there is already
for_each_net_rcu() in kernel, but it requires rcu_read_lock(),
and this can't be sleepable. Also, sometimes it may be need
really prevent net_namespace_list growth, so for_each_net_rcu()
is not fit there.

This patch introduces new rw_semaphore, which will be used
instead of rtnl_mutex to protect net_namespace_list. It is
sleepable and allows not-exclusive iterations over net
namespaces list. It allows to stop using rtnl_lock()
in several places (what is made in next patches) and makes
less the time, we keep rtnl_mutex. Here we just add new lock,
while the explanation of we can remove rtnl_lock() there are
in next patches.

Fine grained locks generally are better, then one big lock,
so let's do that with net_namespace_list, while the situation
allows that.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add more comments

This adds comments to different places to improve
readability.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Rename net_sem to pernet_ops_rwsem

net_sem is some undefined area name, so it will be better
to make the area more defined.

Rename it to pernet_ops_rwsem for better readability and
better intelligibility.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Drop pernet_operations::async

Synchronous pernet_operations are not allowed anymore.
All are asynchronous. So, drop the structure member.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add rtnl_lock_killable()

rtnl_lock() is widely used mutex in kernel. Some of kernel code
does memory allocations under it. In case of memory deficit this
may invoke OOM killer, but the problem is a killed task can't
exit if it's waiting for the mutex. This may be a reason of deadlock
and panic.

This patch adds a new primitive, which responds on SIGKILL, and
it allows to use it in the places, where we don't want to sleep
forever.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Convert rtnetlink_net_ops

rtnetlink_net_init() and rtnetlink_net_exit()
create and destroy netlink socket net::rtnl.

The socket is used to send rtnl notification via
rtnl_net_notifyid(). There is no a problem
to create and destroy it in parallel with other
pernet operations, as we link net in setup_net()
after the socket is created, and destroy
in cleanup_net() after net is unhashed from all
the lists and there is no RCU references on it.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Introduce net_sem for protection of pernet_list

Currently, the mutex is mostly used to protect pernet operations
list. It orders setup_net() and cleanup_net() with parallel
{un,}register_pernet_operations() calls, so ->exit{,batch} methods
of the same pernet operations are executed for a dying net, as
were used to call ->init methods, even after the net namespace
is unlinked from net_namespace_list in cleanup_net().

But there are several problems with scalability. The first one
is that more than one net can't be created or destroyed
at the same moment on the node. For big machines with many cpus
running many containers it's very sensitive.

The second one is that it's need to synchronize_rcu() after net
is removed from net_namespace_list():

Destroy net_ns:
cleanup_net()
mutex_lock(&net_mutex)
list_del_rcu(&net->list)
synchronize_rcu() <--- Sleep there for ages
list_for_each_entry_reverse(ops, &pernet_list, list)
ops_exit_list(ops, &net_exit_list)
list_for_each_entry_reverse(ops, &pernet_list, list)
ops_free_list(ops, &net_exit_list)
mutex_unlock(&net_mutex)

This primitive is not fast, especially on the systems with many processors
and/or when preemptible RCU is enabled in config. So, all the time, while
cleanup_net() is waiting for RCU grace period, creation of new net namespaces
is not possible, the tasks, who makes it, are sleeping on the same mutex:

Create net_ns:
copy_net_ns()
mutex_lock_killable(&net_mutex) <--- Sleep there for ages

I observed 20-30 seconds hangs of "unshare -n" on ordinary 8-cpu laptop
with preemptible RCU enabled after CRIU tests round is finished.

The solution is to convert net_mutex to the rw_semaphore and add fine grain
locks to really small number of pernet_operations, what really need them.

Then, pernet_operations::init/::exit methods, modifying the net-related data,
will require down_read() locking only, while down_write() will be used
for changing pernet_list (i.e., when modules are being loaded and unloaded).

This gives signify performance increase, after all patch set is applied,
like you may see here:

%for i in {1..10000}; do unshare -n bash -c exit; done

*before*
real 1m40,377s
user 0m9,672s
sys 0m19,928s

*after*
real 0m17,007s
user 0m5,311s
sys 0m11,779

(5.8 times faster)

This patch starts replacing net_mutex to net_sem. It adds rw_semaphore,
describes the variables it protects, and makes to use, where appropriate.
net_mutex is still present, and next patches will kick it out step-by-step.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Acked-by: Andrei Vagin <avagin@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: require unique netns identifier

Since we've added support for IFLA_IF_NETNSID for RTM_{DEL,GET,SET,NEW}LINK
it is possible for userspace to send us requests with three different
properties to identify a target network namespace. This affects at least
RTM_{NEW,SET}LINK. Each of them could potentially refer to a different
network namespace which is confusing. For legacy reasons the kernel will
pick the IFLA_NET_NS_PID property first and then look for the
IFLA_NET_NS_FD property but there is no reason to extend this type of
behavior to network namespace ids. The regression potential is quite
minimal since the rtnetlink requests in question either won't allow
IFLA_IF_NETNSID requests before 4.16 is out (RTM_{NEW,SET}LINK) or don't
support IFLA_NET_NS_{PID,FD} (RTM_{DEL,GET}LINK) in the first place.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: remove check for IFLA_IF_NETNSID

RTM_NEWLINK supports the IFLA_IF_NETNSID property since
5bb8ed075428b71492734af66230aa0c07fcc515 so we should not error out
when it is passed.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK

- Backwards Compatibility:
If userspace wants to determine whether RTM_NEWLINK supports the
IFLA_IF_NETNSID property they should first send an RTM_GETLINK request
with IFLA_IF_NETNSID on lo. If either EACCESS is returned or the reply
does not include IFLA_IF_NETNSID userspace should assume that
IFLA_IF_NETNSID is not supported on this kernel.
If the reply does contain an IFLA_IF_NETNSID property userspace
can send an RTM_NEWLINK with a IFLA_IF_NETNSID property. If they receive
EOPNOTSUPP then the kernel does not support the IFLA_IF_NETNSID property
with RTM_NEWLINK. Userpace should then fallback to other means.

- Security:
Callers must have CAP_NET_ADMIN in the owning user namespace of the
target network namespace.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: introduce helper dev_change_tx_queue_len()

This patch promotes the local change_tx_queue_len() to a core
helper function, dev_change_tx_queue_len(), so that rtnetlink
and net-sysfs could share the code. This also prepares for the
following patch.

Note, the -EFAULT in the original code doesn't make sense,
we should propagate the errno from notifiers.

Cc: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

dev: advertise the new ifindex when the netns iface changes

The goal is to let the user follow an interface that moves to another
netns.

CC: Jiri Benc <jbenc@redhat.com>
CC: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: enable IFLA_IF_NETNSID for RTM_DELLINK

- Backwards Compatibility:
If userspace wants to determine whether RTM_DELLINK supports the
IFLA_IF_NETNSID property they should first send an RTM_GETLINK request
with IFLA_IF_NETNSID on lo. If either EACCESS is returned or the reply
does not include IFLA_IF_NETNSID userspace should assume that
IFLA_IF_NETNSID is not supported on this kernel.
If the reply does contain an IFLA_IF_NETNSID property userspace
can send an RTM_DELLINK with a IFLA_IF_NETNSID property. If they receive
EOPNOTSUPP then the kernel does not support the IFLA_IF_NETNSID property
with RTM_DELLINK. Userpace should then fallback to other means.

- Security:
Callers must have CAP_NET_ADMIN in the owning user namespace of the
target network namespace.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: enable IFLA_IF_NETNSID for RTM_SETLINK

- Backwards Compatibility:
If userspace wants to determine whether RTM_SETLINK supports the
IFLA_IF_NETNSID property they should first send an RTM_GETLINK request
with IFLA_IF_NETNSID on lo. If either EACCESS is returned or the reply
does not include IFLA_IF_NETNSID userspace should assume that
IFLA_IF_NETNSID is not supported on this kernel.
If the reply does contain an IFLA_IF_NETNSID property userspace
can send an RTM_SETLINK with a IFLA_IF_NETNSID property. If they receive
EOPNOTSUPP then the kernel does not support the IFLA_IF_NETNSID property
with RTM_SETLINK. Userpace should then fallback to other means.

To retain backwards compatibility the kernel will first check whether a
IFLA_NET_NS_PID or IFLA_NET_NS_FD property has been passed. If either
one is found it will be used to identify the target network namespace.
This implies that users who do not care whether their running kernel
supports IFLA_IF_NETNSID with RTM_SETLINK can pass both
IFLA_NET_NS_{FD,PID} and IFLA_IF_NETNSID referring to the same network
namespace.

- Security:
Callers must have CAP_NET_ADMIN in the owning user namespace of the
target network namespace.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtnetlink: enable IFLA_IF_NETNSID in do_setlink()

RTM_{NEW,SET}LINK already allow operations on other network namespaces
by identifying the target network namespace through IFLA_NET_NS_{FD,PID}
properties. This is done by looking for the corresponding properties in
do_setlink(). Extend do_setlink() to also look for the IFLA_IF_NETNSID
property. This introduces no functional changes since all callers of
do_setlink() currently block IFLA_IF_NETNSID by reporting an error before
they reach do_setlink().

This introduces the helpers:

static struct net *rtnl_link_get_net_by_nlattr(struct net *src_net, struct
nlattr *tb[])

static struct net *rtnl_link_get_net_capable(const struct sk_buff *skb,
struct net *src_net,
struct nlattr *tb[], int cap)

to simplify permission checks and target network namespace retrieval for
RTM_* requests that already support IFLA_NET_NS_{FD,PID} but get extended
to IFLA_IF_NETNSID. To perserve backwards compatibility the helpers look
for IFLA_NET_NS_{FD,PID} properties first before checking for
IFLA_IF_NETNSID.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: Expose number of link up/down transitions

Expose the number of times the link has been going UP or DOWN, and
update the "carrier_changes" counter to be the sum of these two events.
While at it, also update the sysfs-class-net documentation to cover:
carrier_changes (3.15), carrier_up_count (4.16) and carrier_down_count
(4.16)

Signed-off-by: David Decotigny <decot@googlers.com>
[Florian:
* rebase
* add documentation
* merge carrier_changes with up/down counters]
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/core: Add drop counters to VF statistics

Modern hardware can decide to drop packets going to/from a VF.
Add receive and transmit drop counters to be displayed at hypervisor
layer in iproute2 per VF statistics.

Signed-off-by: Eugenia Emantayev <eugenia@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>