Revert "net: Re-use and set mono_delivery_time bit for userspace tstamp packets"

This reverts commit 885c36e59f46375c138de18ff1692f18eff67b7f.

The patch currently broke the bpf selftest test_tc_dtime because
uapi field __sk_buff->tstamp_type depends on skb->mono_delivery_time which
does not necessarily mean mono with the original fix as the bit was re-used
for userspace timestamp as well to avoid tstamp reset in the forwarding
path. To solve this we need to keep mono_delivery_time as is and
introduce another bit called user_delivery_time and fall back to the
initial proposal of setting the user_delivery_time bit based on
sk_clockid set from userspace.

Fixes: 885c36e59f46 ("net: Re-use and set mono_delivery_time bit for userspace tstamp packets")
Link: https://lore.kernel.org/netdev/bc037db4-58bb-4861-ac31-a361a93841d3@linux.dev/
Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: annotate data-races around ignore_outgoing

ignore_outgoing is read locklessly from dev_queue_xmit_nit()
and packet_getsockopt()

Add appropriate READ_ONCE()/WRITE_ONCE() annotations.

syzbot reported:

BUG: KCSAN: data-race in dev_queue_xmit_nit / packet_setsockopt

write to 0xffff888107804542 of 1 bytes by task 22618 on cpu 0:
packet_setsockopt+0xd83/0xfd0 net/packet/af_packet.c:4003
do_sock_setsockopt net/socket.c:2311 [inline]
__sys_setsockopt+0x1d8/0x250 net/socket.c:2334
__do_sys_setsockopt net/socket.c:2343 [inline]
__se_sys_setsockopt net/socket.c:2340 [inline]
__x64_sys_setsockopt+0x66/0x80 net/socket.c:2340
do_syscall_64+0xd3/0x1d0
entry_SYSCALL_64_after_hwframe+0x6d/0x75

read to 0xffff888107804542 of 1 bytes by task 27 on cpu 1:
dev_queue_xmit_nit+0x82/0x620 net/core/dev.c:2248
xmit_one net/core/dev.c:3527 [inline]
dev_hard_start_xmit+0xcc/0x3f0 net/core/dev.c:3547
__dev_queue_xmit+0xf24/0x1dd0 net/core/dev.c:4335
dev_queue_xmit include/linux/netdevice.h:3091 [inline]
batadv_send_skb_packet+0x264/0x300 net/batman-adv/send.c:108
batadv_send_broadcast_skb+0x24/0x30 net/batman-adv/send.c:127
batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:392 [inline]
batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline]
batadv_iv_send_outstanding_bat_ogm_packet+0x3f0/0x4b0 net/batman-adv/bat_iv_ogm.c:1700
process_one_work kernel/workqueue.c:3254 [inline]
process_scheduled_works+0x465/0x990 kernel/workqueue.c:3335
worker_thread+0x526/0x730 kernel/workqueue.c:3416
kthread+0x1d1/0x210 kernel/kthread.c:388
ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

value changed: 0x00 -> 0x01

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 27 Comm: kworker/u8:1 Tainted: G W 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet

Fixes: fa788d986a3a ("packet: add sockopt to ignore outgoing packets")
Reported-by: syzbot+c669c1136495a2e7c31f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/CANn89i+Z7MfbkBLOv=p7KZ7=K1rKHO4P1OL5LYDCtBiyqsa9oQ@mail.gmail.com/T/#t
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Add getsockopt support for PACKET_COPY_THRESH

Currently getsockopt does not support PACKET_COPY_THRESH,
and we are unable to get the value of PACKET_COPY_THRESH
socket option through getsockopt.

This patch adds getsockopt support for PACKET_COPY_THRESH.

In addition, this patch converts access to copy_thresh to
READ_ONCE/WRITE_ONCE.

Signed-off-by: Juntong Deng <juntong.deng@outlook.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/AM6PR03MB58487A9704FD150CF76F542899272@AM6PR03MB5848.eurprd03.prod.outlook.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: Re-use and set mono_delivery_time bit for userspace tstamp packets

Bridge driver today has no support to forward the userspace timestamp
packets and ends up resetting the timestamp. ETF qdisc checks the
packet coming from userspace and encounters to be 0 thereby dropping
time sensitive packets. These changes will allow userspace timestamps
packets to be forwarded from the bridge to NIC drivers.

Setting the same bit (mono_delivery_time) to avoid dropping of
userspace tstamp packets in the forwarding path.

Existing functionality of mono_delivery_time remains unaltered here,
instead just extended with userspace tstamp support for bridge
forwarding path.

Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20240301201348.2815102-1-quic_abchauha@quicinc.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: fill in MODULE_DESCRIPTION() for AF_PACKET

W=1 builds now warn if module is built without a MODULE_DESCRIPTION().
Add description to net/packet/af_packet.c

Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20240104144119.1319055-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

packet: add a generic drop reason for receive

Commit da37845fdce2 ("packet: uses kfree_skb() for errors.") switches
from consume_skb to kfree_skb to improve error handling. However, this
could bring a lot of noises when we monitor real packet drops in
kfree_skb[1], because in tpacket_rcv or packet_rcv only packet clones
can be freed, not actual packets.

Adding a generic drop reason to allow distinguish these "clone drops".

[1]: https://lore.kernel.org/netdev/CABWYdi00L+O30Q=Zah28QwZ_5RU-xcxLFUK2Zj08A8MrLk9jzg@mail.gmail.com/
Fixes: da37845fdce2 ("packet: uses kfree_skb() for errors.")
Suggested-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/ZW4piNbx3IenYnuw@debian.debian
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

packet: Move reference count in packet_sock to atomic_long_t

In some potential instances the reference count on struct packet_sock
could be saturated and cause overflows which gets the kernel a bit
confused. To prevent this, move to a 64-bit atomic reference count on
64-bit architectures to prevent the possibility of this type to overflow.

Because we can not handle saturation, using refcount_t is not possible
in this place. Maybe someday in the future if it changes it could be
used. Also, instead of using plain atomic64_t, use atomic_long_t instead.
32-bit machines tend to be memory-limited (i.e. anything that increases
a reference uses so much memory that you can't actually get to 2**32
references). 32-bit architectures also tend to have serious problems
with 64-bit atomics. Hence, atomic_long_t is the more natural solution.

Reported-by: "The UK's National Cyber Security Centre (NCSC)" <security@ncsc.gov.uk>
Co-developed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable@kernel.org
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231201131021.19999-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

af_packet: Fix fortified memcpy() without flex array.

Sergei Trofimovich reported a regression [0] caused by commit a0ade8404c3b
("af_packet: Fix warning of fortified memcpy() in packet_getname().").

It introduced a flex array sll_addr_flex in struct sockaddr_ll as a
union-ed member with sll_addr to work around the fortified memcpy() check.

However, a userspace program uses a struct that has struct sockaddr_ll in
the middle, where a flex array is illegal to exist.

include/linux/if_packet.h:24:17: error: flexible array member 'sockaddr_ll::<unnamed union>::<unnamed struct>::sll_addr_flex' not at end of 'struct packet_info_t'
24 | __DECLARE_FLEX_ARRAY(unsigned char, sll_addr_flex);
| ^~~~~~~~~~~~~~~~~~~~

To fix the regression, let's go back to the first attempt [1] telling
memcpy() the actual size of the array.

Reported-by: Sergei Trofimovich <slyich@gmail.com>
Closes: https://github.com/NixOS/nixpkgs/pull/252587#issuecomment-1741733002 [0]
Link: https://lore.kernel.org/netdev/20230720004410.87588-3-kuniyu@amazon.com/ [1]
Fixes: a0ade8404c3b ("af_packet: Fix warning of fortified memcpy() in packet_getname().")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20231009153151.75688-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net/packet: change packet_alloc_skb() to allow bigger paged allocations

packet_alloc_skb() is currently calling sock_alloc_send_pskb()
forcing order-0 page allocations.

Switch to PAGE_ALLOC_COSTLY_ORDER, to increase max size by 8x.

Also add logic to increase the linear part if needed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tahsin Erdogan <trdgn@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20230801205254.400094-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/packet: annotate data-races around tp->status

Another syzbot report [1] is about tp->status lockless reads
from __packet_get_status()

[1]
BUG: KCSAN: data-race in __packet_rcv_has_room / __packet_set_status

write to 0xffff888117d7c080 of 8 bytes by interrupt on cpu 0:
__packet_set_status+0x78/0xa0 net/packet/af_packet.c:407
tpacket_rcv+0x18bb/0x1a60 net/packet/af_packet.c:2483
deliver_skb net/core/dev.c:2173 [inline]
__netif_receive_skb_core+0x408/0x1e80 net/core/dev.c:5337
__netif_receive_skb_one_core net/core/dev.c:5491 [inline]
__netif_receive_skb+0x57/0x1b0 net/core/dev.c:5607
process_backlog+0x21f/0x380 net/core/dev.c:5935
__napi_poll+0x60/0x3b0 net/core/dev.c:6498
napi_poll net/core/dev.c:6565 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6698
__do_softirq+0xc1/0x265 kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x57/0xa0 kernel/softirq.c:650
sysvec_apic_timer_interrupt+0x6d/0x80 arch/x86/kernel/apic/apic.c:1106
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
smpboot_thread_fn+0x33c/0x4a0 kernel/smpboot.c:112
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffff888117d7c080 of 8 bytes by interrupt on cpu 1:
__packet_get_status net/packet/af_packet.c:436 [inline]
packet_lookup_frame net/packet/af_packet.c:524 [inline]
__tpacket_has_room net/packet/af_packet.c:1255 [inline]
__packet_rcv_has_room+0x3f9/0x450 net/packet/af_packet.c:1298
tpacket_rcv+0x275/0x1a60 net/packet/af_packet.c:2285
deliver_skb net/core/dev.c:2173 [inline]
dev_queue_xmit_nit+0x38a/0x5e0 net/core/dev.c:2243
xmit_one net/core/dev.c:3574 [inline]
dev_hard_start_xmit+0xcf/0x3f0 net/core/dev.c:3594
__dev_queue_xmit+0xefb/0x1d10 net/core/dev.c:4244
dev_queue_xmit include/linux/netdevice.h:3088 [inline]
can_send+0x4eb/0x5d0 net/can/af_can.c:276
bcm_can_tx+0x314/0x410 net/can/bcm.c:302
bcm_tx_timeout_handler+0xdb/0x260
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x217/0x700 kernel/time/hrtimer.c:1749
hrtimer_run_softirq+0xd6/0x120 kernel/time/hrtimer.c:1766
__do_softirq+0xc1/0x265 kernel/softirq.c:571
run_ksoftirqd+0x17/0x20 kernel/softirq.c:939
smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

value changed: 0x0000000000000000 -> 0x0000000020000081

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 6.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023

Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20230803145600.2937518-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: annotate data-races around sk->sk_priority

sk_getsockopt() runs locklessly. This means sk->sk_priority
can be read while other threads are changing its value.

Other reads also happen without socket lock being held.

Add missing annotations where needed.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: annotate data-races around sk->sk_mark

sk->sk_mark is often read while another thread could change the value.

Fixes: 4a19ec5800fc ("[NET]: Introducing socket mark socket option.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: Fix warning of fortified memcpy() in packet_getname().

syzkaller found a warning in packet_getname() [0], where we try to
copy 16 bytes to sockaddr_ll.sll_addr[8].

Some devices (ip6gre, vti6, ip6tnl) have 16 bytes address expressed
by struct in6_addr. Also, Infiniband has 32 bytes as MAX_ADDR_LEN.

The write seems to overflow, but actually not since we use struct
sockaddr_storage defined in __sys_getsockname() and its size is 128
(_K_SS_MAXSIZE) bytes. Thus, we have sufficient room after sll_addr[]
as __data[].

To avoid the warning, let's add a flex array member union-ed with
sll_addr.

Another option would be to use strncpy() and limit the copied length
to sizeof(sll_addr), but it will return the partial address and break
an application that passes sockaddr_storage to getsockname().

[0]:
memcpy: detected field-spanning write (size 16) of single field "sll->sll_addr" at net/packet/af_packet.c:3604 (size 8)
WARNING: CPU: 0 PID: 255 at net/packet/af_packet.c:3604 packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
Modules linked in:
CPU: 0 PID: 255 Comm: syz-executor750 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #4
Hardware name: linux,dummy-virt (DT)
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
lr : packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
sp : ffff800089887bc0
x29: ffff800089887bc0 x28: ffff000010f80f80 x27: 0000000000000003
x26: dfff800000000000 x25: ffff700011310f80 x24: ffff800087d55000
x23: dfff800000000000 x22: ffff800089887c2c x21: 0000000000000010
x20: ffff00000de08310 x19: ffff800089887c20 x18: ffff800086ab1630
x17: 20646c6569662065 x16: 6c676e697320666f x15: 0000000000000001
x14: 1fffe0000d56d7ca x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 3e60944c3da92b00
x8 : 3e60944c3da92b00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000898874f8 x4 : ffff800086ac99e0 x3 : ffff8000803f8808
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
__sys_getsockname+0x168/0x24c net/socket.c:2042
__do_sys_getsockname net/socket.c:2057 [inline]
__se_sys_getsockname net/socket.c:2054 [inline]
__arm64_sys_getsockname+0x7c/0x94 net/socket.c:2054
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x134/0x240 arch/arm64/kernel/syscall.c:139
do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:188
el0_svc+0x2c/0x7c arch/arm64/kernel/entry-common.c:647
el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591

Fixes: df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230724213425.22920-3-kuniyu@amazon.com
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)

Remove ->sendpage() and ->sendpage_locked(). sendmsg() with
MSG_SPLICE_PAGES should be used instead. This allows multiple pages and
multipage folios to be passed through.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> # for net/can
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: linux-afs@lists.infradead.org
cc: mptcp@lists.linux.dev
cc: rds-devel@oss.oracle.com
cc: tipc-discussion@lists.sourceforge.net
cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

af_packet: do not use READ_ONCE() in packet_bind()

A recent patch added READ_ONCE() in packet_bind() and packet_bind_spkt()

This is better handled by reading pkt_sk(sk)->num later
in packet_do_bind() while appropriate lock is held.

READ_ONCE() in writers are often an evidence of something being wrong.

Fixes: 822b5a1c17df ("af_packet: Fix data-races of pkt_sk(sk)->num.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230526154342.2533026-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

af_packet: Fix data-races of pkt_sk(sk)->num.

syzkaller found a data race of pkt_sk(sk)->num.

The value is changed under lock_sock() and po->bind_lock, so we
need READ_ONCE() to access pkt_sk(sk)->num without these locks in
packet_bind_spkt(), packet_bind(), and sk_diag_fill().

Note that WRITE_ONCE() is already added by commit c7d2ef5dd4b0
("net/packet: annotate accesses to po->bind").

BUG: KCSAN: data-race in packet_bind / packet_do_bind

write (marked) to 0xffff88802ffd1cee of 2 bytes by task 7322 on cpu 0:
packet_do_bind+0x446/0x640 net/packet/af_packet.c:3236
packet_bind+0x99/0xe0 net/packet/af_packet.c:3321
__sys_bind+0x19b/0x1e0 net/socket.c:1803
__do_sys_bind net/socket.c:1814 [inline]
__se_sys_bind net/socket.c:1812 [inline]
__x64_sys_bind+0x40/0x50 net/socket.c:1812
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x72/0xdc

read to 0xffff88802ffd1cee of 2 bytes by task 7318 on cpu 1:
packet_bind+0xbf/0xe0 net/packet/af_packet.c:3322
__sys_bind+0x19b/0x1e0 net/socket.c:1803
__do_sys_bind net/socket.c:1814 [inline]
__se_sys_bind net/socket.c:1812 [inline]
__x64_sys_bind+0x40/0x50 net/socket.c:1812
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x72/0xdc

value changed: 0x0300 -> 0x0000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7318 Comm: syz-executor.4 Not tainted 6.3.0-13380-g7fddb5b5300c #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 96ec6327144e ("packet: Diag core and basic socket info dumping")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20230524232934.50950-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: add vlan_get_protocol_and_depth() helper

Before blamed commit, pskb_may_pull() was used instead
of skb_header_pointer() in __vlan_get_protocol() and friends.

Few callers depended on skb->head being populated with MAC header,
syzbot caught one of them (skb_mac_gso_segment())

Add vlan_get_protocol_and_depth() to make the intent clearer
and use it where sensible.

This is a more generic fix than commit e9d3f80935b6
("net/af_packet: make sure to pull mac header") which was
dealing with a similar issue.

kernel BUG at include/linux/skbuff.h:2655 !
invalid opcode: 0000 [#1] SMP KASAN
CPU: 0 PID: 1441 Comm: syz-executor199 Not tainted 6.1.24-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
RIP: 0010:__skb_pull include/linux/skbuff.h:2655 [inline]
RIP: 0010:skb_mac_gso_segment+0x68f/0x6a0 net/core/gro.c:136
Code: fd 48 8b 5c 24 10 44 89 6b 70 48 c7 c7 c0 ae 0d 86 44 89 e6 e8 a1 91 d0 00 48 c7 c7 00 af 0d 86 48 89 de 31 d2 e8 d1 4a e9 ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41
RSP: 0018:ffffc90001bd7520 EFLAGS: 00010286
RAX: ffffffff8469736a RBX: ffff88810f31dac0 RCX: ffff888115a18b00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90001bd75e8 R08: ffffffff84697183 R09: fffff5200037adf9
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000012
R13: 000000000000fee5 R14: 0000000000005865 R15: 000000000000fed7
FS: 000055555633f300(0000) GS:ffff8881f6a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 0000000116fea000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
[<ffffffff847018dd>] __skb_gso_segment+0x32d/0x4c0 net/core/dev.c:3419
[<ffffffff8470398a>] skb_gso_segment include/linux/netdevice.h:4819 [inline]
[<ffffffff8470398a>] validate_xmit_skb+0x3aa/0xee0 net/core/dev.c:3725
[<ffffffff84707042>] __dev_queue_xmit+0x1332/0x3300 net/core/dev.c:4313
[<ffffffff851a9ec7>] dev_queue_xmit+0x17/0x20 include/linux/netdevice.h:3029
[<ffffffff851b4a82>] packet_snd net/packet/af_packet.c:3111 [inline]
[<ffffffff851b4a82>] packet_sendmsg+0x49d2/0x6470 net/packet/af_packet.c:3142
[<ffffffff84669a12>] sock_sendmsg_nosec net/socket.c:716 [inline]
[<ffffffff84669a12>] sock_sendmsg net/socket.c:736 [inline]
[<ffffffff84669a12>] __sys_sendto+0x472/0x5f0 net/socket.c:2139
[<ffffffff84669c75>] __do_sys_sendto net/socket.c:2151 [inline]
[<ffffffff84669c75>] __se_sys_sendto net/socket.c:2147 [inline]
[<ffffffff84669c75>] __x64_sys_sendto+0xe5/0x100 net/socket.c:2147
[<ffffffff8551d40f>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff8551d40f>] do_syscall_64+0x2f/0x50 arch/x86/entry/common.c:80
[<ffffffff85600087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 469aceddfa3e ("vlan: consolidate VLAN parsing code and limit max parsing depth")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Toke Høiland-Jørgensen <toke@redhat.com>
Cc: Willem de Bruijn <willemb@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: Don't send zero-byte data in packet_sendmsg_spkt().

syzkaller reported a warning below [0].

We can reproduce it by sending 0-byte data from the (AF_PACKET,
SOCK_PACKET) socket via some devices whose dev->hard_header_len
is 0.

struct sockaddr_pkt addr = {
.spkt_family = AF_PACKET,
.spkt_device = "tun0",
};
int fd;

fd = socket(AF_PACKET, SOCK_PACKET, 0);
sendto(fd, NULL, 0, 0, (struct sockaddr *)&addr, sizeof(addr));

We have a similar fix for the (AF_PACKET, SOCK_RAW) socket as
commit dc633700f00f ("net/af_packet: check len when min_header_len
equals to 0").

Let's add the same test for the SOCK_PACKET socket.

[0]:
skb_assert_len
WARNING: CPU: 1 PID: 19945 at include/linux/skbuff.h:2552 skb_assert_len include/linux/skbuff.h:2552 [inline]
WARNING: CPU: 1 PID: 19945 at include/linux/skbuff.h:2552 __dev_queue_xmit+0x1f26/0x31d0 net/core/dev.c:4159
Modules linked in:
CPU: 1 PID: 19945 Comm: syz-executor.0 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:skb_assert_len include/linux/skbuff.h:2552 [inline]
RIP: 0010:__dev_queue_xmit+0x1f26/0x31d0 net/core/dev.c:4159
Code: 89 de e8 1d a2 85 fd 84 db 75 21 e8 64 a9 85 fd 48 c7 c6 80 2a 1f 86 48 c7 c7 c0 06 1f 86 c6 05 23 cf 27 04 01 e8 fa ee 56 fd <0f> 0b e8 43 a9 85 fd 0f b6 1d 0f cf 27 04 31 ff 89 de e8 e3 a1 85
RSP: 0018:ffff8880217af6e0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90001133000
RDX: 0000000000040000 RSI: ffffffff81186922 RDI: 0000000000000001
RBP: ffff8880217af8b0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888030045640
R13: ffff8880300456b0 R14: ffff888030045650 R15: ffff888030045718
FS: 00007fc5864da640(0000) GS:ffff88806cd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020005740 CR3: 000000003f856003 CR4: 0000000000770ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
dev_queue_xmit include/linux/netdevice.h:3085 [inline]
packet_sendmsg_spkt+0xc4b/0x1230 net/packet/af_packet.c:2066
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg+0x1b4/0x200 net/socket.c:747
____sys_sendmsg+0x331/0x970 net/socket.c:2503
___sys_sendmsg+0x11d/0x1c0 net/socket.c:2557
__sys_sendmmsg+0x18c/0x430 net/socket.c:2643
__do_sys_sendmmsg net/socket.c:2672 [inline]
__se_sys_sendmmsg net/socket.c:2669 [inline]
__x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2669
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3c/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fc58791de5d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 73 9f 1b 00 f7 d8 64 89 01 48
RSP: 002b:00007fc5864d9cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004bbf80 RCX: 00007fc58791de5d
RDX: 0000000000000001 RSI: 0000000020005740 RDI: 0000000000000004
RBP: 00000000004bbf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fc58797e530 R15: 0000000000000000
</TASK>
---[ end trace 0000000000000000 ]---
skb len=0 headroom=16 headlen=0 tailroom=304
mac=(16,0) net=(16,-1) trans=-1
shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0))
csum(0x0 ip_summed=0 complete_sw=0 valid=0 level=0)
hash(0x0 sw=0 l4=0) proto=0x0000 pkttype=0 iif=0
dev name=sit0 feat=0x00000006401d7869
sk family=17 type=10 proto=0

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: support mergeable feature of virtio

Packet sockets, like tap, can be used as the backend for kernel vhost.
In packet sockets, virtio net header size is currently hardcoded to be
the size of struct virtio_net_hdr, which is 10 bytes; however, it is not
always the case: some virtio features, such as mrg_rxbuf, need virtio
net header to be 12-byte long.

Mergeable buffers, as a virtio feature, is worthy of supporting: packets
that are larger than one-mbuf size will be dropped in vhost worker's
handle_rx if mrg_rxbuf feature is not used, but large packets
cannot be avoided and increasing mbuf's size is not economical.

With this virtio feature enabled by virtio-user, packet sockets with
hardcoded 10-byte virtio net header will parse mac head incorrectly in
packet_snd by taking the last two bytes of virtio net header as part of
mac header.
This incorrect mac header parsing will cause packet to be dropped due to
invalid ether head checking in later under-layer device packet receiving.

By adding extra field vnet_hdr_sz with utilizing holes in struct
packet_sock to record currently used virtio net header size and supporting
extra sockopt PACKET_VNET_HDR_SZ to set specified vnet_hdr_sz, packet
sockets can know the exact length of virtio net header that virtio user
gives.
In packet_snd, tpacket_snd and packet_recvmsg, instead of using
hardcoded virtio net header size, it can get the exact vnet_hdr_sz from
corresponding packet_sock, and parse mac header correctly based on this
information to avoid the packets being mistakenly dropped.

Signed-off-by: Jianfeng Tan <henry.tjf@antgroup.com>
Co-developed-by: Anqi Shen <amy.saq@antgroup.com>
Signed-off-by: Anqi Shen <amy.saq@antgroup.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: introduce a config option to tweak MAX_SKB_FRAGS

Currently, MAX_SKB_FRAGS value is 17.

For standard tcp sendmsg() traffic, no big deal because tcp_sendmsg()
attempts order-3 allocations, stuffing 32768 bytes per frag.

But with zero copy, we use order-0 pages.

For BIG TCP to show its full potential, we add a config option
to be able to fit up to 45 segments per skb.

This is also needed for BIG TCP rx zerocopy, as zerocopy currently
does not support skbs with frag list.

We have used MAX_SKB_FRAGS=45 value for years at Google before
we deployed 4K MTU, with no adverse effect, other than
a recent issue in mlx4, fixed in commit 26782aad00cc
("net/mlx4: MLX4_TX_BOUNCE_BUFFER_SIZE depends on MAX_SKB_FRAGS")

Back then, goal was to be able to receive full size (64KB) GRO
packets without the frag_list overhead.

Note that /proc/sys/net/core/max_skb_frags can also be used to limit
the number of fragments TCP can use in tx packets.

By default we keep the old/legacy value of 17 until we get
more coverage for the updated values.

Sizes of struct skb_shared_info on 64bit arches

MAX_SKB_FRAGS | sizeof(struct skb_shared_info):
==============================================
17 320
21 320+64 = 384
25 320+128 = 448
29 320+192 = 512
33 320+256 = 576
37 320+320 = 640
41 320+384 = 704
45 320+448 = 768

This inflation might cause problems for drivers assuming they could pack
both the incoming packet (for MTU=1500) and skb_shared_info in half a page,
using build_skb().

v3: fix build error when CONFIG_NET=n
v2: fix two build errors assuming MAX_SKB_FRAGS was "unsigned long"

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/20230323162842.1935061-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/packet: remove po->xmit

Use PACKET_SOCK_QDISC_BYPASS atomic bit instead of a pointer.

This removes one indirect call in fast path,
and READ_ONCE()/WRITE_ONCE() annotations as well.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Willem de Bruijn <willemb@google.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: convert po->pressure to an atomic flag

Not only this removes some READ_ONCE()/WRITE_ONCE(),
this also removes one integer.

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

net/packet: convert po->running to an atomic flag

Instead of consuming 32 bits for po->running, use
one available bit in po->flags.

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

net/packet: convert po->has_vnet_hdr to an atomic flag

po->has_vnet_hdr can be read locklessly.

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

net/packet: convert po->tp_loss to an atomic flag

tp_loss can be read locklessly.

Convert it to an atomic flag to avoid races.

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

net/packet: convert po->tp_tx_has_off to an atomic flag

This is to use existing space in po->flags, and reclaim
the storage used by the non atomic bit fields.

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

net/packet: annotate accesses to po->tp_tstamp

tp_tstamp is read locklessly.

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

net/packet: convert po->auxdata to an atomic flag

po->auxdata can be read while another thread
is changing its value, potentially raising KCSAN splat.

Convert it to PACKET_SOCK_AUXDATA flag.

Fixes: 8dc419447415 ("[PACKET]: Add optional checksum computation for recvmsg")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: convert po->origdev to an atomic flag

syzbot/KCAN reported that po->origdev can be read
while another thread is changing its value.

We can avoid this splat by converting this field
to an actual bit.

Following patches will convert remaining 1bit fields.

Fixes: 80feaacb8a64 ("[AF_PACKET]: Add option to return orig_dev to userspace.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: annotate accesses to po->xmit

po->xmit can be set from setsockopt(PACKET_QDISC_BYPASS),
while read locklessly.

Use READ_ONCE()/WRITE_ONCE() to avoid potential load/store
tearing issues.

Fixes: d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: no longer support SOCK_REFCNT_DEBUG feature

Commit e48c414ee61f ("[INET]: Generalise the TCP sock ID lookup routines")
commented out the definition of SOCK_REFCNT_DEBUG in 2005 and later another
commit 463c84b97f24 ("[NET]: Introduce inet_connection_sock") removed it.
Since we could track all of them through bpf and kprobe related tools
and the feature could print loads of information which might not be
that helpful even under a little bit pressure, the whole feature which
has been inactive for many years is no longer supported.

Link: https://lore.kernel.org/lkml/20230211065153.54116-1-kerneljasonxing@gmail.com/
Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: add TP_STATUS_GSO_TCP for tp_status

Introduce TP_STATUS_GSO_TCP tp_status flag to tell the af_packet user
that this is a TCP GSO packet. When parsing IPv4 BIG TCP packets in
tcpdump/libpcap, it can use tp_len as the IPv4 packet len when this
flag is set, as iph tot_len is set to 0 for IPv4 BIG TCP packets.

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>

treewide: use get_random_u32_below() instead of deprecated function

This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
(E)

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

net/packet: add PACKET_FANOUT_FLAG_IGNORE_OUTGOING

Extend packet socket option PACKET_IGNORE_OUTGOING to fanout groups.

The socket option sets ptype.ignore_outgoing, which makes
dev_queue_xmit_nit skip the socket.

When the socket joins a fanout group, the option is not reflected in
the struct ptype of the group. dev_queue_xmit_nit only tests the
fanout ptype, so the flag is ignored once a socket joins a
fanout group.

Inheriting the option from a socket would change established behavior.
Different sockets in the group can set different flags, and can also
change them at runtime.

Testing in packet_rcv_fanout defeats the purpose of the original
patch, which is to avoid skb_clone in dev_queue_xmit_nit (esp. for
MSG_ZEROCOPY packets).

Instead, introduce a new fanout group flag with the same behavior.

Tested with https://github.com/wdebruij/kerneltools/blob/master/tests/test_psock_fanout_ignore_outgoing.c

Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221027211014.3581513-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: dev: Convert sa_data to flexible array in struct sockaddr

One of the worst offenders of "fake flexible arrays" is struct sockaddr,
as it is the classic example of why GCC and Clang have been traditionally
forced to treat all trailing arrays as fake flexible arrays: in the
distant misty past, sa_data became too small, and code started just
treating it as a flexible array, even though it was fixed-size. The
special case by the compiler is specifically that sizeof(sa->sa_data)
and FORTIFY_SOURCE (which uses __builtin_object_size(sa->sa_data, 1))
do not agree (14 and -1 respectively), which makes FORTIFY_SOURCE treat
it as a flexible array.

However, the coming -fstrict-flex-arrays compiler flag will remove
these special cases so that FORTIFY_SOURCE can gain coverage over all
the trailing arrays in the kernel that are _not_ supposed to be treated
as a flexible array. To deal with this change, convert sa_data to a true
flexible array. To keep the structure size the same, move sa_data into
a union with a newly introduced sa_data_min with the original size. The
result is that FORTIFY_SOURCE can continue to have no idea how large
sa_data may actually be, but anything using sizeof(sa->sa_data) must
switch to sizeof(sa->sa_data_min).

Cc: Jens Axboe <axboe@kernel.dk>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: David Ahern <dsahern@kernel.org>
Cc: Dylan Yudaken <dylany@fb.com>
Cc: Yajun Deng <yajun.deng@linux.dev>
Cc: Petr Machata <petrm@nvidia.com>
Cc: Hangbin Liu <liuhangbin@gmail.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: syzbot <syzkaller@googlegroups.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221018095503.never.671-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM_COMPLETE

CHECKSUM_COMPLETE signals that skb->csum stores the sum over the
entire packet. It does not imply that an embedded l4 checksum
field has been validated.

Fixes: 682f048bd494 ("af_packet: pass checksum validation status to the user")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20221128161812.640098-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

treewide: use prandom_u32_max() when possible, part 1

Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:

@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)

@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@

- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);

// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@

((T)get_random_u32()@p & (LITERAL))

// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@

value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))

// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@

- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)

@collapse_ret@
type T;
identifier VAR;
expression E;
@@

{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}

@drop_var@
type T;
identifier VAR;
@@

{
- T VAR;
... when != VAR
}

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

net/af_packet: registration process optimization in packet_init()

Now, register_pernet_subsys() and register_netdevice_notifier() are both
after sock_register(). It can create PF_PACKET socket and process socket
once sock_register() successfully. It is possible PF_PACKET socket is
creating but register_pernet_subsys() and register_netdevice_notifier()
are not registered yet. Thus net->packet.sklist_lock and net->packet.sklist
will be accessed without initialization that is done in packet_net_init().
Although this is a low probability scenario.

Move register_pernet_subsys() and register_netdevice_notifier() to the
front in packet_init(). Correspondingly, adjust the unregister process
in packet_exit().

Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: move from strlcpy with unused retval to strscpy

Follow the advice of the below link and prefer 'strscpy' in this
subsystem. Conversion is 1:1 because the return value is not used.
Generated by a coccinelle script.

Link: https://lore.kernel.org/r/CAHk-=wgfRnXz0W3D37d01q3JFkr_i_uTL=V6A6G1oUZcprmknw@mail.gmail.com/
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20220818210227.8611-1-wsa+renesas@sang-engineering.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/af_packet: check len when min_header_len equals to 0

User can use AF_PACKET socket to send packets with the length of 0.
When min_header_len equals to 0, packet_snd will call __dev_queue_xmit
to send packets, and sock->type can be any type.

Reported-by: syzbot+5ea725c25d06fb9114c4@syzkaller.appspotmail.com
Fixes: fd1894224407 ("bpf: Don't redirect packets with invalid pkt_len")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rename reference+tracking helpers

Netdev reference helpers have a dev_ prefix for historic
reasons. Renaming the old helpers would be too much churn
but we can rename the tracking ones which are relatively
recent and should be the default for new code.

Rename:
dev_hold_track() -> netdev_hold()
dev_put_track() -> netdev_put()
dev_replace_track() -> netdev_ref_replace()

Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/af_packet: make sure to pull mac header

GSO assumes skb->head contains link layer headers.

tun device in some case can provide base 14 bytes,
regardless of VLAN being used or not.

After blamed commit, we can end up setting a network
header offset of 18+, we better pull the missing
bytes to avoid a posible crash in GSO.

syzbot report was:
kernel BUG at include/linux/skbuff.h:2699!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 3601 Comm: syz-executor210 Not tainted 5.18.0-syzkaller-11338-g2c5ca23f7414 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__skb_pull include/linux/skbuff.h:2699 [inline]
RIP: 0010:skb_mac_gso_segment+0x48f/0x530 net/core/gro.c:136
Code: 00 48 c7 c7 00 96 d4 8a c6 05 cb d3 45 06 01 e8 26 bb d0 01 e9 2f fd ff ff 49 c7 c4 ea ff ff ff e9 f1 fe ff ff e8 91 84 19 fa <0f> 0b 48 89 df e8 97 44 66 fa e9 7f fd ff ff e8 ad 44 66 fa e9 48
RSP: 0018:ffffc90002e2f4b8 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000012 RCX: 0000000000000000
RDX: ffff88805bb58000 RSI: ffffffff8760ed0f RDI: 0000000000000004
RBP: 0000000000005dbc R08: 0000000000000004 R09: 0000000000000fe0
R10: 0000000000000fe4 R11: 0000000000000000 R12: 0000000000000fe0
R13: ffff88807194d780 R14: 1ffff920005c5e9b R15: 0000000000000012
FS: 000055555730f300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000200015c0 CR3: 0000000071ff8000 CR4: 0000000000350ee0
Call Trace:
<TASK>
__skb_gso_segment+0x327/0x6e0 net/core/dev.c:3411
skb_gso_segment include/linux/netdevice.h:4749 [inline]
validate_xmit_skb+0x6bc/0xf10 net/core/dev.c:3669
validate_xmit_skb_list+0xbc/0x120 net/core/dev.c:3719
sch_direct_xmit+0x3d1/0xbe0 net/sched/sch_generic.c:327
__dev_xmit_skb net/core/dev.c:3815 [inline]
__dev_queue_xmit+0x14a1/0x3a00 net/core/dev.c:4219
packet_snd net/packet/af_packet.c:3071 [inline]
packet_sendmsg+0x21cb/0x5550 net/packet/af_packet.c:3102
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xcf/0x120 net/socket.c:734
____sys_sendmsg+0x6eb/0x810 net/socket.c:2492
___sys_sendmsg+0xf3/0x170 net/socket.c:2546
__sys_sendmsg net/socket.c:2575 [inline]
__do_sys_sendmsg net/socket.c:2584 [inline]
__se_sys_sendmsg net/socket.c:2582 [inline]
__x64_sys_sendmsg+0x132/0x220 net/socket.c:2582
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f4b95da06c9
Code: 28 c3 e8 4a 15 00 00 66 2e 0f 1f 84 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd7defc4c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ffd7defc4f0 RCX: 00007f4b95da06c9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 0000000000000003 R08: bb1414ac00000050 R09: bb1414ac00000050
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd7defc4e0 R14: 00007ffd7defc4d8 R15: 00007ffd7defc4d4
</TASK>

Fixes: dfed913e8b55 ("net/af_packet: add VLAN support for AF_PACKET SOCK_RAW GSO")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: SO_RCVMARK socket option for SO_MARK with recvmsg()

Adding a new socket option, SO_RCVMARK, to indicate that SO_MARK
should be included in the ancillary data returned by recvmsg().

Renamed the sock_recv_ts_and_drops() function to sock_recv_cmsgs().

Signed-off-by: Erin MacNeil <lnx.erin@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/r/20220427200259.2564-1-lnx.erin@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/af_packet: add VLAN support for AF_PACKET SOCK_RAW GSO

Currently, the kernel drops GSO VLAN tagged packet if it's created with
socket(AF_PACKET, SOCK_RAW, 0) plus virtio_net_hdr.

The reason is AF_PACKET doesn't adjust the skb network header if there is
a VLAN tag. Then after virtio_net_hdr_set_proto() called, the skb->protocol
will be set to ETH_P_IP/IPv6. And in later inet/ipv6_gso_segment() the skb
is dropped as network header position is invalid.

Let's handle VLAN packets by adjusting network header position in
packet_parse_headers(). The adjustment is safe and does not affect the
later xmit as tap device also did that.

In packet_snd(), packet_parse_headers() need to be moved before calling
virtio_net_hdr_set_proto(), so we can set correct skb->protocol and
network header first.

There is no need to update tpacket_snd() as it calls packet_parse_headers()
in tpacket_fill_skb(), which is already before calling virtio_net_hdr_*
functions.

skb->no_fcs setting is also moved upper to make all skb settings together
and keep consistency with function packet_sendmsg_spkt().

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20220425014502.985464-1-liuhangbin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: remove noblock parameter from skb_recv_datagram()

skb_recv_datagram() has two parameters 'flags' and 'noblock' that are
merged inside skb_recv_datagram() by 'flags | (noblock ? MSG_DONTWAIT : 0)'

As 'flags' may contain MSG_DONTWAIT as value most callers split the 'flags'
into 'flags' and 'noblock' with finally obsolete bit operations like this:

skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, flags & MSG_DONTWAIT, &rc);

And this is not even done consistently with the 'flags' parameter.

This patch removes the obsolete and costly splitting into two parameters
and only performs bit operations when really needed on the caller side.

One missing conversion thankfully reported by kernel test robot. I missed
to enable kunit tests to build the mctp code.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: fix packet_sock xmit return value checking

packet_sock xmit could be dev_queue_xmit, which also returns negative
errors. So only checking positive errors is not enough, or userspace
sendmsg may return success while packet is not send out.

Move the net_xmit_errno() assignment in the braces as checkpatch.pl said
do not use assignment in if condition.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Handle delivery_time in skb->tstamp during network tapping with af_packet

A latter patch will set the skb->mono_delivery_time to flag the skb->tstamp
is used as the mono delivery_time (EDT) instead of the (rcv) timestamp.
skb_clear_tstamp() will then keep this delivery_time during forwarding.

This patch is to make the network tapping (with af_packet) to handle
the delivery_time stored in skb->tstamp.

Regardless of tapping at the ingress or egress, the tapped skb is
received by the af_packet socket, so it is ingress to the af_packet
socket and it expects the (rcv) timestamp.

When tapping at egress, dev_queue_xmit_nit() is used. It has already
expected skb->tstamp may have delivery_time, so it does
skb_clone()+net_timestamp_set() to ensure the cloned skb has
the (rcv) timestamp before passing to the af_packet sk.
This patch only adds to clear the skb->mono_delivery_time
bit in net_timestamp_set().

When tapping at ingress, it currently expects the skb->tstamp is either 0
or the (rcv) timestamp. Meaning, the tapping at ingress path
has already expected the skb->tstamp could be 0 and it will get
the (rcv) timestamp by ktime_get_real() when needed.

There are two cases for tapping at ingress:

One case is af_packet queues the skb to its sk_receive_queue.
The skb is either not shared or new clone created. The newly
added skb_clear_delivery_time() is called to clear the
delivery_time (if any) and set the (rcv) timestamp if
needed before the skb is queued to the sk_receive_queue.

Another case, the ingress skb is directly copied to the rx_ring
and tpacket_get_timestamp() is used to get the (rcv) timestamp.
The newly added skb_tstamp() is used in tpacket_get_timestamp()
to check the skb->mono_delivery_time bit before returning skb->tstamp.
As mentioned earlier, the tapping@ingress has already expected
the skb may not have the (rcv) timestamp (because no sk has asked
for it) and has handled this case by directly calling ktime_get_real().

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: fix slab-out-of-bounds access in packet_recvmsg()

syzbot found that when an AF_PACKET socket is using PACKET_COPY_THRESH
and mmap operations, tpacket_rcv() is queueing skbs with
garbage in skb->cb[], triggering a too big copy [1]

Presumably, users of af_packet using mmap() already gets correct
metadata from the mapped buffer, we can simply make sure
to clear 12 bytes that might be copied to user space later.

BUG: KASAN: stack-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline]
BUG: KASAN: stack-out-of-bounds in packet_recvmsg+0x56c/0x1150 net/packet/af_packet.c:3489
Write of size 165 at addr ffffc9000385fb78 by task syz-executor233/3631

CPU: 0 PID: 3631 Comm: syz-executor233 Not tainted 5.17.0-rc7-syzkaller-02396-g0b3660695e80 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0xf/0x336 mm/kasan/report.c:255
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold+0x83/0xdf mm/kasan/report.c:459
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
memcpy+0x39/0x60 mm/kasan/shadow.c:66
memcpy include/linux/fortify-string.h:225 [inline]
packet_recvmsg+0x56c/0x1150 net/packet/af_packet.c:3489
sock_recvmsg_nosec net/socket.c:948 [inline]
sock_recvmsg net/socket.c:966 [inline]
sock_recvmsg net/socket.c:962 [inline]
____sys_recvmsg+0x2c4/0x600 net/socket.c:2632
___sys_recvmsg+0x127/0x200 net/socket.c:2674
__sys_recvmsg+0xe2/0x1a0 net/socket.c:2704
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fdfd5954c29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffcf8e71e48 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fdfd5954c29
RDX: 0000000000000000 RSI: 0000000020000500 RDI: 0000000000000005
RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcf8e71e60
R13: 00000000000f4240 R14: 000000000000c1ff R15: 00007ffcf8e71e54
</TASK>

addr ffffc9000385fb78 is located in stack of task syz-executor233/3631 at offset 32 in frame:
____sys_recvmsg+0x0/0x600 include/linux/uio.h:246

this frame has 1 object:
[32, 160) 'addr'

Memory state around the buggy address:
ffffc9000385fa80: 00 04 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00
ffffc9000385fb00: 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00
>ffffc9000385fb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f3
^
ffffc9000385fc00: f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 f1
ffffc9000385fc80: f1 f1 f1 00 f2 f2 f2 00 f2 f2 f2 00 00 00 00 00
==================================================================

Fixes: 0fb375fb9b93 ("[AF_PACKET]: Allow for > 8 byte hardware addresses.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220312232958.3535620-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

af_packet: fix data-race in packet_setsockopt / packet_setsockopt

When packet_setsockopt( PACKET_FANOUT_DATA ) reads po->fanout,
no lock is held, meaning that another thread can change po->fanout.

Given that po->fanout can only be set once during the socket lifetime
(it is only cleared from fanout_release()), we can use
READ_ONCE()/WRITE_ONCE() to document the race.

BUG: KCSAN: data-race in packet_setsockopt / packet_setsockopt

write to 0xffff88813ae8e300 of 8 bytes by task 14653 on cpu 0:
fanout_add net/packet/af_packet.c:1791 [inline]
packet_setsockopt+0x22fe/0x24a0 net/packet/af_packet.c:3931
__sys_setsockopt+0x209/0x2a0 net/socket.c:2180
__do_sys_setsockopt net/socket.c:2191 [inline]
__se_sys_setsockopt net/socket.c:2188 [inline]
__x64_sys_setsockopt+0x62/0x70 net/socket.c:2188
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 0xffff88813ae8e300 of 8 bytes by task 14654 on cpu 1:
packet_setsockopt+0x691/0x24a0 net/packet/af_packet.c:3935
__sys_setsockopt+0x209/0x2a0 net/socket.c:2180
__do_sys_setsockopt net/socket.c:2191 [inline]
__se_sys_setsockopt net/socket.c:2188 [inline]
__x64_sys_setsockopt+0x62/0x70 net/socket.c:2188
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: 0x0000000000000000 -> 0xffff888106f8c000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14654 Comm: syz-executor.3 Not tainted 5.16.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 47dceb8ecdc1 ("packet: add classic BPF fanout mode")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220201022358.330621-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: fix information leakage in /proc/net/ptype

In one net namespace, after creating a packet socket without binding
it to a device, users in other net namespaces can observe the new
`packet_type` added by this packet socket by reading `/proc/net/ptype`
file. This is minor information leakage as packet socket is
namespace aware.

Add a net pointer in `packet_type` to keep the net namespace of
of corresponding packet socket. In `ptype_seq_show`, this net pointer
must be checked when it is not NULL.

Fixes: 2feb27dbe00c ("[NETNS]: Minor information leak via /proc/net/ptype file.")
Signed-off-by: Congyu Liu <liu3101@purdue.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: fix tracking issues in packet_do_bind()

It appears that my changes in packet_do_bind() were
slightly wrong.

syzbot found that calling bind() twice would trigger
a false positive.

Remove proto_curr/dev_curr variables and rewrite things
to be less confusing (like not having to use netdev_tracker_alloc(),
and instead use the standard dev_hold_track())

Fixes: f1d9268e0618 ("net: add net device refcount tracker to struct packet_type")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Link: https://lore.kernel.org/r/20220107183953.3886647-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: Don't include filter.h from net/sock.h

sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of struct sk_filter instead.
This decreases the number of rebuilt objects when bpf.h
is touched from ~5k to ~1k.

There's a lot of missing includes this was masking. Primarily
in networking tho, this time.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org

net: add net device refcount tracker to struct packet_type

Most notable changes are in af_packet, tipc ones are trivial.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jon Maloy <jmaloy@redhat.com>
Cc: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: drop nopreempt requirement on sock_prot_inuse_add()

This is distracting really, let's make this simpler,
because many callers had to take care of this
by themselves, even if on x86 this adds more
code than really needed.

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

net/packet: rx_owner_map depends on pg_vec

Packet sockets may switch ring versions. Avoid misinterpreting state
between versions, whose fields share a union. rx_owner_map is only
allocated with a packet ring (pg_vec) and both are swapped together.
If pg_vec is NULL, meaning no packet ring was allocated, then neither
was rx_owner_map. And the field may be old state from a tpacket_v3.

Fixes: 61fad6816fc1 ("net/packet: tpacket_rcv: avoid a producer race condition")
Reported-by: Syzbot <syzbot+1ac0994a0a0c55151121@syzkaller.appspotmail.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20211215143937.106178-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

af_packet: Introduce egress hook

Add egress hook for AF_PACKET sockets that have the PACKET_QDISC_BYPASS
socket option set to on, which allows packets to escape without being
filtered in the egress path.

This patch only updates the AF_PACKET path, it does not update
dev_direct_xmit() so the XDP infrastructure has a chance to bypass
Netfilter.

[lukas: acquire rcu_read_lock, fix typos, rebase]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/packet: clarify source of pr_*() messages

Add pr_fmt macro to spell out the source of messages in prefix.

Before this patch:

packet size is too long (1543 > 1518)

With this patch:

af_packet: packet size is too long (1543 > 1518)

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Remove redundant if statements

The 'if (dev)' statement already move into dev_{put , hold}, so remove
redundant if statements.

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

net: sock: introduce sk_error_report

This patch introduces a function wrapper to call the sk_error_report
callback. That will prepare to add additional handling whenever
sk_error_report is called, for example to trace socket errors.

Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Remove redundant assignment to ret

Variable ret is set to '0' or '-EBUSY', but this value is never read
as it is not used later on, hence it is a redundant assignment and
can be removed.

Clean up the following clang-analyzer warning:

net/packet/af_packet.c:3936:4: warning: Value stored to 'ret' is never
read [clang-analyzer-deadcode.DeadStores].

net/packet/af_packet.c:3933:4: warning: Value stored to 'ret' is never
read [clang-analyzer-deadcode.DeadStores].

No functional change.

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/packet: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
by explicitly adding a break statement instead of letting the code fall
through to the next case.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

net/packet: annotate accesses to po->ifindex

Like prior patch, we need to annotate lockless accesses to po->ifindex
For instance, packet_getname() is reading po->ifindex (twice) while
another thread is able to change po->ifindex.

KCSAN reported:

BUG: KCSAN: data-race in packet_do_bind / packet_getname

write to 0xffff888143ce3cbc of 4 bytes by task 25573 on cpu 1:
packet_do_bind+0x420/0x7e0 net/packet/af_packet.c:3191
packet_bind+0xc3/0xd0 net/packet/af_packet.c:3255
__sys_bind+0x200/0x290 net/socket.c:1637
__do_sys_bind net/socket.c:1648 [inline]
__se_sys_bind net/socket.c:1646 [inline]
__x64_sys_bind+0x3d/0x50 net/socket.c:1646
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888143ce3cbc of 4 bytes by task 25578 on cpu 0:
packet_getname+0x5b/0x1a0 net/packet/af_packet.c:3525
__sys_getsockname+0x10e/0x1a0 net/socket.c:1887
__do_sys_getsockname net/socket.c:1902 [inline]
__se_sys_getsockname net/socket.c:1899 [inline]
__x64_sys_getsockname+0x3e/0x50 net/socket.c:1899
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000 -> 0x00000001

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 25578 Comm: syz-executor.5 Not tainted 5.13.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

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

net/packet: annotate accesses to po->bind

tpacket_snd(), packet_snd(), packet_getname() and packet_seq_show()
can read po->num without holding a lock. This means other threads
can change po->num at the same time.

KCSAN complained about this known fact [1]
Add READ_ONCE()/WRITE_ONCE() to address the issue.

[1] BUG: KCSAN: data-race in packet_do_bind / packet_sendmsg

write to 0xffff888131a0dcc0 of 2 bytes by task 24714 on cpu 0:
packet_do_bind+0x3ab/0x7e0 net/packet/af_packet.c:3181
packet_bind+0xc3/0xd0 net/packet/af_packet.c:3255
__sys_bind+0x200/0x290 net/socket.c:1637
__do_sys_bind net/socket.c:1648 [inline]
__se_sys_bind net/socket.c:1646 [inline]
__x64_sys_bind+0x3d/0x50 net/socket.c:1646
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888131a0dcc0 of 2 bytes by task 24719 on cpu 1:
packet_snd net/packet/af_packet.c:2899 [inline]
packet_sendmsg+0x317/0x3570 net/packet/af_packet.c:3040
sock_sendmsg_nosec net/socket.c:654 [inline]
sock_sendmsg net/socket.c:674 [inline]
____sys_sendmsg+0x360/0x4d0 net/socket.c:2350
___sys_sendmsg net/socket.c:2404 [inline]
__sys_sendmsg+0x1ed/0x270 net/socket.c:2433
__do_sys_sendmsg net/socket.c:2442 [inline]
__se_sys_sendmsg net/socket.c:2440 [inline]
__x64_sys_sendmsg+0x42/0x50 net/socket.c:2440
do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000 -> 0x1200

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 24719 Comm: syz-executor.5 Not tainted 5.13.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

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

net/packet: annotate data race in packet_sendmsg()

There is a known race in packet_sendmsg(), addressed
in commit 32d3182cd2cd ("net/packet: fix race in tpacket_snd()")

Now we have data_race(), we can use it to avoid a future KCSAN warning,
as syzbot loves stressing af_packet sockets :)

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

net: packetmmap: fix only tx timestamp on request

The packetmmap tx ring should only return timestamps if requested via
setsockopt PACKET_TIMESTAMP, as documented. This allows compatibility
with non-timestamp aware user-space code which checks
tp_status == TP_STATUS_AVAILABLE; not expecting additional timestamp
flags to be set in tp_status.

Fixes: b9c32fb27170 ("packet: if hw/sw ts enabled in rx/tx ring, report which ts we got")
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Richard Sanger <rsanger@wand.net.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: remove data races in fanout operations

af_packet fanout uses RCU rules to ensure f->arr elements
are not dismantled before RCU grace period.

However, it lacks rcu accessors to make sure KCSAN and other tools
wont detect data races. Stupid compilers could also play games.

Fixes: dc99f600698d ("packet: Add fanout support.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: "Gong, Sishuai" <sishuai@purdue.edu>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Fix a typo in af_packet.c

s/sequencially/sequentially/

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Improve the comment about LL header visibility criteria

The "dev_has_header" function, recently added in
commit d549699048b4 ("net/packet: fix packet receive on L3 devices
without visible hard header"),
is more accurate as criteria for determining whether a device exposes
the LL header to upper layers, because in addition to dev->header_ops,
it also checks for dev->header_ops->create.

When transmitting an skb on a device, dev_hard_header can be called to
generate an LL header. dev_hard_header will only generate a header if
dev->header_ops->create is present.

Signed-off-by: Xie He <xie.he.0141@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20210205224124.21345-1-xie.he.0141@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: af_packet: fix procfs header for 64-bit pointers

On 64-bit systems the packet procfs header field names following 'sk'
are not aligned correctly:

sk RefCnt Type Proto Iface R Rmem User Inode
00000000605d2c64 3 3 0003 7 1 450880 0 16643
00000000080e9b80 2 2 0000 0 0 0 0 17404
00000000b23b8a00 2 2 0000 0 0 0 0 17421
...

With this change field names are correctly aligned:

sk RefCnt Type Proto Iface R Rmem User Inode
000000005c3b1d97 3 3 0003 7 1 21568 0 16178
000000007be55bb7 3 3 fbce 8 1 0 0 16250
00000000be62127d 3 3 fbcd 8 1 0 0 16254
...

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Link: https://lore.kernel.org/r/54917251d8433735d9a24e935a6cb8eb88b4058a.1608103684.git.baruch@tkos.co.il
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: fix proc_fs init handling in af_packet and tls

proc_fs was used, in af_packet, without a surrounding #ifdef,
although there is no hard dependency on proc_fs.
That caused the initialization of the af_packet module to fail
when CONFIG_PROC_FS=n.

Specifically, proc_create_net() was used in af_packet.c,
and when it fails, packet_net_init() returns -ENOMEM.
It will always fail when the kernel is compiled without proc_fs,
because, proc_create_net() for example always returns NULL.

The calling order that starts in af_packet.c is as follows:
packet_init()
register_pernet_subsys()
register_pernet_operations()
__register_pernet_operations()
ops_init()
ops->init() (packet_net_ops.init=packet_net_init())
proc_create_net()

It worked in the past because register_pernet_subsys()'s return value
wasn't checked before this Commit 36096f2f4fa0 ("packet: Fix error path in
packet_init.").
It always returned an error, but was not checked before, so everything
was working even when CONFIG_PROC_FS=n.

The fix here is simply to add the necessary #ifdef.

This also fixes a similar error in tls_proc.c, that was found by Jakub
Kicinski.

Fixes: d26b698dd3cd ("net/tls: add skeleton of MIB statistics")
Fixes: 36096f2f4fa0 ("packet: Fix error path in packet_init")
Signed-off-by: Yonatan Linik <yonatanlinik@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/packet: fix packet receive on L3 devices without visible hard header

In the patchset merged by commit b9fcf0a0d826
("Merge branch 'support-AF_PACKET-for-layer-3-devices'") L3 devices which
did not have header_ops were given one for the purpose of protocol parsing
on af_packet transmit path.

That change made af_packet receive path regard these devices as having a
visible L3 header and therefore aligned incoming skb->data to point to the
skb's mac_header. Some devices, such as ipip, xfrmi, and others, do not
reset their mac_header prior to ingress and therefore their incoming
packets became malformed.

Ideally these devices would reset their mac headers, or af_packet would be
able to rely on dev->hard_header_len being 0 for such cases, but it seems
this is not the case.

Fix by changing af_packet RX ll visibility criteria to include the
existence of a '.create()' header operation, which is used when creating
a device hard header - via dev_hard_header() - by upper layers, and does
not exist in these L3 devices.

As this predicate may be useful in other situations, add it as a common
dev_has_header() helper in netdevice.h.

Fixes: b9fcf0a0d826 ("Merge branch 'support-AF_PACKET-for-layer-3-devices'")
Signed-off-by: Eyal Birger <eyal.birger@gmail.com>
Acked-by: Jason A. Donenfeld <Jason@zx2c4.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20201121062817.3178900-1-eyal.birger@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net: don't include ethtool.h from netdevice.h

linux/netdevice.h is included in very many places, touching any
of its dependecies causes large incremental builds.

Drop the linux/ethtool.h include, linux/netdevice.h just needs
a forward declaration of struct ethtool_ops.

Fix all the places which made use of this implicit include.

Acked-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Shannon Nelson <snelson@pensando.io>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Link: https://lore.kernel.org/r/20201120225052.1427503-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/packet: make packet_fanout.arr size configurable up to 64K

One use case of PACKET_FANOUT is lockless reception with one socket
per CPU. 256 is a practical limit on increasingly many machines.

Increase PACKET_FANOUT_MAX to 64K. Expand setsockopt PACKET_FANOUT to
take an extra argument max_num_members. Also explicitly define a
fanout_args struct, instead of implicitly casting to an integer. This
documents the API and simplifies the control flow.

If max_num_members is not specified or is set to 0, then 256 is used,
same as before.

Signed-off-by: Tanner Love <tannerlove@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/packet: Fix a comment about network_header

skb->nh.raw has been renamed as skb->network_header in 2007, in
commit b0e380b1d8a8 ("[SK_BUFF]: unions of just one member don't get
anything done, kill them")

So here we change it to the new name.

Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Fix a comment about mac_header

1. Change all "dev->hard_header" to "dev->header_ops"

2. On receiving incoming frames when header_ops == NULL:

The comment only says what is wrong, but doesn't say what is right.
This patch changes the comment to make it clear what is right.

3. On transmitting and receiving outgoing frames when header_ops == NULL:

The comment explains that the LL header will be later added by the driver.

However, I think it's better to simply say that the LL header is invisible
to us. This phrasing is better from a software engineering perspective,
because this makes it clear that what happens in the driver should be
hidden from us and we should not care about what happens internally in the
driver.

4. On resuming the LL header (for RAW frames) when header_ops == NULL:

The comment says we are "unlikely" to restore the LL header.

However, we should say that we are "unable" to restore it.
It's not possible (rather than not likely) to restore it, because:

1) There is no way for us to restore because the LL header internally
processed by the driver should be invisible to us.

2) In function packet_rcv and tpacket_rcv, the code only tries to restore
the LL header when header_ops != NULL.

Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Fix a comment about hard_header_len and headroom allocation

This comment is outdated and no longer reflects the actual implementation
of af_packet.c.

Reasons for the new comment:

1.

In af_packet.c, the function packet_snd first reserves a headroom of
length (dev->hard_header_len + dev->needed_headroom).
Then if the socket is a SOCK_DGRAM socket, it calls dev_hard_header,
which calls dev->header_ops->create, to create the link layer header.
If the socket is a SOCK_RAW socket, it "un-reserves" a headroom of
length (dev->hard_header_len), and checks if the user has provided a
header sized between (dev->min_header_len) and (dev->hard_header_len)
(in dev_validate_header).
This shows the developers of af_packet.c expect hard_header_len to
be consistent with header_ops.

2.

In af_packet.c, the function packet_sendmsg_spkt has a FIXME comment.
That comment states that prepending an LL header internally in a driver
is considered a bug. I believe this bug can be fixed by setting
hard_header_len to 0, making the internal header completely invisible
to af_packet.c (and requesting the headroom in needed_headroom instead).

3.

There is a commit for a WiFi driver:
commit 9454f7a895b8 ("mwifiex: set needed_headroom, not hard_header_len")
According to the discussion about it at:
https://patchwork.kernel.org/patch/11407493/
The author tried to set the WiFi driver's hard_header_len to the Ethernet
header length, and request additional header space internally needed by
setting needed_headroom.
This means this usage is already adopted by driver developers.

Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Brian Norris <briannorris@chromium.org>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Remove unused macro BLOCK_PRIV

BLOCK_PRIV is never used after it was introduced.
So better to remove it.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/packet: fix overflow in tpacket_rcv

Using tp_reserve to calculate netoff can overflow as
tp_reserve is unsigned int and netoff is unsigned short.

This may lead to macoff receving a smaller value then
sizeof(struct virtio_net_hdr), and if po->has_vnet_hdr
is set, an out-of-bounds write will occur when
calling virtio_net_hdr_from_skb.

The bug is fixed by converting netoff to unsigned int
and checking if it exceeds USHRT_MAX.

This addresses CVE-2020-14386

Fixes: 8913336a7e8d ("packet: add PACKET_RESERVE sockopt")
Signed-off-by: Or Cohen <orcohen@paloaltonetworks.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

af_packet: TPACKET_V3: fix fill status rwlock imbalance

After @blk_fill_in_prog_lock is acquired there is an early out vnet
situation that can occur. In that case, the rwlock needs to be
released.

Also, since @blk_fill_in_prog_lock is only acquired when @tp_version
is exactly TPACKET_V3, only release it on that exact condition as
well.

And finally, add sparse annotation so that it is clearer that
prb_fill_curr_block() and prb_clear_blk_fill_status() are acquiring
and releasing @blk_fill_in_prog_lock, respectively. sparse is still
unable to understand the balance, but the warnings are now on a
higher level that make more sense.

Fixes: 632ca50f2cbd ("af_packet: TPACKET_V3: replace busy-wait loop")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: pass a sockptr_t into ->setsockopt

Rework the remaining setsockopt code to pass a sockptr_t instead of a
plain user pointer. This removes the last remaining set_fs(KERNEL_DS)
outside of architecture specific code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154]
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: switch copy_bpf_fprog_from_user to sockptr_t

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: make ->{get,set}sockopt in proto_ops optional

Just check for a NULL method instead of wiring up
sock_no_{get,set}sockopt.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: simplify cBPF setsockopt compat handling

Add a helper that copies either a native or compat bpf_fprog from
userspace after verifying the length, and remove the compat setsockopt
handlers that now aren't required.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: TPACKET_V3: replace busy-wait loop

A busy-wait loop is used to implement waiting for bits to be copied
from the skb to the kernel buffer before retiring a block. This is
a problem on PREEMPT_RT because the copying task could be preempted
by the busy-waiting task and thus live lock in the busy-wait loop.

Replace the busy-wait logic with an rwlock_t. This provides lockdep
coverage and makes the code RT ready.

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/packet: remove redundant initialization of variable err

The variable err is being initialized 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/packet: tpacket_rcv: avoid a producer race condition

PACKET_RX_RING can cause multiple writers to access the same slot if a
fast writer wraps the ring while a slow writer is still copying. This
is particularly likely with few, large, slots (e.g., GSO packets).

Synchronize kernel thread ownership of rx ring slots with a bitmap.

Writers acquire a slot race-free by testing tp_status TP_STATUS_KERNEL
while holding the sk receive queue lock. They release this lock before
copying and set tp_status to TP_STATUS_USER to release to userspace
when done. During copying, another writer may take the lock, also see
TP_STATUS_KERNEL, and start writing to the same slot.

Introduce a new rx_owner_map bitmap with a bit per slot. To acquire a
slot, test and set with the lock held. To release race-free, update
tp_status and owner bit as a transaction, so take the lock again.

This is the one of a variety of discussed options (see Link below):

* instead of a shadow ring, embed the data in the slot itself, such as
in tp_padding. But any test for this field may match a value left by
userspace, causing deadlock.

* avoid the lock on release. This leaves a small race if releasing the
shadow slot before setting TP_STATUS_USER. The below reproducer showed
that this race is not academic. If releasing the slot after tp_status,
the race is more subtle. See the first link for details.

* add a new tp_status TP_KERNEL_OWNED to avoid the transactional store
of two fields. But, legacy applications may interpret all non-zero
tp_status as owned by the user. As libpcap does. So this is possible
only opt-in by newer processes. It can be added as an optional mode.

* embed the struct at the tail of pg_vec to avoid extra allocation.
The implementation proved no less complex than a separate field.

The additional locking cost on release adds contention, no different
than scaling on multicore or multiqueue h/w. In practice, below
reproducer nor small packet tcpdump showed a noticeable change in
perf report in cycles spent in spinlock. Where contention is
problematic, packet sockets support mitigation through PACKET_FANOUT.
And we can consider adding opt-in state TP_KERNEL_OWNED.

Easy to reproduce by running multiple netperf or similar TCP_STREAM
flows concurrently with `tcpdump -B 129 -n greater 60000`.

Based on an earlier patchset by Jon Rosen. See links below.

I believe this issue goes back to the introduction of tpacket_rcv,
which predates git history.

Link: https://www.mail-archive.com/netdev@vger.kernel.org/msg237222.html
Suggested-by: Jon Rosen <jrosen@cisco.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jon Rosen <jrosen@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: tpacket_rcv: do not increment ring index on drop

In one error case, tpacket_rcv drops packets after incrementing the
ring producer index.

If this happens, it does not update tp_status to TP_STATUS_USER and
thus the reader is stalled for an iteration of the ring, causing out
of order arrival.

The only such error path is when virtio_net_hdr_from_skb fails due
to encountering an unknown GSO type.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: refactoring code for prb_calc_retire_blk_tmo

If __ethtool_get_link_ksettings() is failed and with
non-zero value, prb_calc_retire_blk_tmo() should return
DEFAULT_PRB_RETIRE_TOV firstly.

This patch is to refactory code and make it more readable.

Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: clarify timestamp overflow

The memory mapped packet socket data structure in version 1 through 3
all contain 32-bit second values for the packet time stamps, which makes
them suffer from the overflow of time_t in y2038 or y2106 (depending
on whether user space interprets the value as signed or unsigned).

The implementation uses the deprecated getnstimeofday() function.

In order to get rid of that, this changes the code to use
ktime_get_real_ts64() as a replacement, documenting the nature of the
overflow. As long as the user applications treat the timestamps as
unsigned, or only use the difference between timestamps, they are
fine, and changing the timestamps to 64-bit wouldn't require a more
invasive user space API change.

Note: a lot of other APIs suffer from incompatible structures when
time_t gets redefined to 64-bit in 32-bit user space, but this one
does not.

Acked-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/lkml/CAF=yD-Jomr-gWSR-EBNKnSpFL46UeG564FLfqTCMNEm-prEaXA@mail.gmail.com/T/#u
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

af_packet: set defaule value for tmo

There is softlockup when using TPACKET_V3:
...
NMI watchdog: BUG: soft lockup - CPU#2 stuck for 60010ms!
(__irq_svc) from [<c0558a0c>] (_raw_spin_unlock_irqrestore+0x44/0x54)
(_raw_spin_unlock_irqrestore) from [<c027b7e8>] (mod_timer+0x210/0x25c)
(mod_timer) from [<c0549c30>]
(prb_retire_rx_blk_timer_expired+0x68/0x11c)
(prb_retire_rx_blk_timer_expired) from [<c027a7ac>]
(call_timer_fn+0x90/0x17c)
(call_timer_fn) from [<c027ab6c>] (run_timer_softirq+0x2d4/0x2fc)
(run_timer_softirq) from [<c021eaf4>] (__do_softirq+0x218/0x318)
(__do_softirq) from [<c021eea0>] (irq_exit+0x88/0xac)
(irq_exit) from [<c0240130>] (msa_irq_exit+0x11c/0x1d4)
(msa_irq_exit) from [<c0209cf0>] (handle_IPI+0x650/0x7f4)
(handle_IPI) from [<c02015bc>] (gic_handle_irq+0x108/0x118)
(gic_handle_irq) from [<c0558ee4>] (__irq_usr+0x44/0x5c)
...

If __ethtool_get_link_ksettings() is failed in
prb_calc_retire_blk_tmo(), msec and tmo will be zero, so tov_in_jiffies
is zero and the timer expire for retire_blk_timer is turn to
mod_timer(&pkc->retire_blk_timer, jiffies + 0),
which will trigger cpu usage of softirq is 100%.

Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.")
Tested-by: Xiao Jiangfeng <xiaojiangfeng@huawei.com>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: fix data-race in fanout_flow_is_huge()

KCSAN reported the following data-race [1]

Adding a couple of READ_ONCE()/WRITE_ONCE() should silence it.

Since the report hinted about multiple cpus using the history
concurrently, I added a test avoiding writing on it if the
victim slot already contains the desired value.

[1]

BUG: KCSAN: data-race in fanout_demux_rollover / fanout_demux_rollover

read to 0xffff8880b01786cc of 4 bytes by task 18921 on cpu 1:
fanout_flow_is_huge net/packet/af_packet.c:1303 [inline]
fanout_demux_rollover+0x33e/0x3f0 net/packet/af_packet.c:1353
packet_rcv_fanout+0x34e/0x490 net/packet/af_packet.c:1453
deliver_skb net/core/dev.c:1888 [inline]
dev_queue_xmit_nit+0x15b/0x540 net/core/dev.c:1958
xmit_one net/core/dev.c:3195 [inline]
dev_hard_start_xmit+0x3f5/0x430 net/core/dev.c:3215
__dev_queue_xmit+0x14ab/0x1b40 net/core/dev.c:3792
dev_queue_xmit+0x21/0x30 net/core/dev.c:3825
neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530
neigh_output include/net/neighbour.h:511 [inline]
ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
__ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
__ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
NF_HOOK_COND include/linux/netfilter.h:294 [inline]
ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
dst_output include/net/dst.h:436 [inline]
ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179
ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795
udp_v6_send_skb.isra.0+0x3ec/0xa70 net/ipv6/udp.c:1173
udpv6_sendmsg+0x1906/0x1c20 net/ipv6/udp.c:1471
inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg+0x9f/0xc0 net/socket.c:657
___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311
__sys_sendmmsg+0x123/0x350 net/socket.c:2413
__do_sys_sendmmsg net/socket.c:2442 [inline]
__se_sys_sendmmsg net/socket.c:2439 [inline]
__x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439
do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880b01786cc of 4 bytes by task 18922 on cpu 0:
fanout_flow_is_huge net/packet/af_packet.c:1306 [inline]
fanout_demux_rollover+0x3a4/0x3f0 net/packet/af_packet.c:1353
packet_rcv_fanout+0x34e/0x490 net/packet/af_packet.c:1453
deliver_skb net/core/dev.c:1888 [inline]
dev_queue_xmit_nit+0x15b/0x540 net/core/dev.c:1958
xmit_one net/core/dev.c:3195 [inline]
dev_hard_start_xmit+0x3f5/0x430 net/core/dev.c:3215
__dev_queue_xmit+0x14ab/0x1b40 net/core/dev.c:3792
dev_queue_xmit+0x21/0x30 net/core/dev.c:3825
neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530
neigh_output include/net/neighbour.h:511 [inline]
ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
__ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
__ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
NF_HOOK_COND include/linux/netfilter.h:294 [inline]
ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
dst_output include/net/dst.h:436 [inline]
ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179
ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795
udp_v6_send_skb.isra.0+0x3ec/0xa70 net/ipv6/udp.c:1173
udpv6_sendmsg+0x1906/0x1c20 net/ipv6/udp.c:1471
inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg+0x9f/0xc0 net/socket.c:657
___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311
__sys_sendmmsg+0x123/0x350 net/socket.c:2413
__do_sys_sendmmsg net/socket.c:2442 [inline]
__se_sys_sendmmsg net/socket.c:2439 [inline]
__x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439
do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18922 Comm: syz-executor.3 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 3b3a5b0aab5b ("packet: rollover huge flows before small flows")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

netfilter: drop bridge nf reset from nf_reset

commit 174e23810cd31
("sk_buff: drop all skb extensions on free and skb scrubbing") made napi
recycle always drop skb extensions. The additional skb_ext_del() that is
performed via nf_reset on napi skb recycle is not needed anymore.

Most nf_reset() calls in the stack are there so queued skb won't block
'rmmod nf_conntrack' indefinitely.

This removes the skb_ext_del from nf_reset, and renames it to a more
fitting nf_reset_ct().

In a few selected places, add a call to skb_ext_reset to make sure that
no active extensions remain.

I am submitting this for "net", because we're still early in the release
cycle. The patch applies to net-next too, but I think the rename causes
needless divergence between those trees.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

net/packet: fix race in tpacket_snd()

packet_sendmsg() checks tx_ring.pg_vec to decide
if it must call tpacket_snd().

Problem is that the check is lockless, meaning another thread
can issue a concurrent setsockopt(PACKET_TX_RING ) to flip
tx_ring.pg_vec back to NULL.

Given that tpacket_snd() grabs pg_vec_lock mutex, we can
perform the check again to solve the race.

syzbot reported :

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 11429 Comm: syz-executor394 Not tainted 5.3.0-rc4+ #101
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:packet_lookup_frame+0x8d/0x270 net/packet/af_packet.c:474
Code: c1 ee 03 f7 73 0c 80 3c 0e 00 0f 85 cb 01 00 00 48 8b 0b 89 c0 4c 8d 24 c1 48 b8 00 00 00 00 00 fc ff df 4c 89 e1 48 c1 e9 03 <80> 3c 01 00 0f 85 94 01 00 00 48 8d 7b 10 4d 8b 3c 24 48 b8 00 00
RSP: 0018:ffff88809f82f7b8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff8880a45c7030 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 1ffff110148b8e06 RDI: ffff8880a45c703c
RBP: ffff88809f82f7e8 R08: ffff888087aea200 R09: fffffbfff134ae50
R10: fffffbfff134ae4f R11: ffffffff89a5727f R12: 0000000000000000
R13: 0000000000000001 R14: ffff8880a45c6ac0 R15: 0000000000000000
FS: 00007fa04716f700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa04716edb8 CR3: 0000000091eb4000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
packet_current_frame net/packet/af_packet.c:487 [inline]
tpacket_snd net/packet/af_packet.c:2667 [inline]
packet_sendmsg+0x590/0x6250 net/packet/af_packet.c:2975
sock_sendmsg_nosec net/socket.c:637 [inline]
sock_sendmsg+0xd7/0x130 net/socket.c:657
___sys_sendmsg+0x3e2/0x920 net/socket.c:2311
__sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413
__do_sys_sendmmsg net/socket.c:2442 [inline]
__se_sys_sendmmsg net/socket.c:2439 [inline]
__x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439
do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: Block execution of tasks waiting for transmit to complete in AF_PACKET

When an application is run that:
a) Sets its scheduler to be SCHED_FIFO
and
b) Opens a memory mapped AF_PACKET socket, and sends frames with the
MSG_DONTWAIT flag cleared, its possible for the application to hang
forever in the kernel. This occurs because when waiting, the code in
tpacket_snd calls schedule, which under normal circumstances allows
other tasks to run, including ksoftirqd, which in some cases is
responsible for freeing the transmitted skb (which in AF_PACKET calls a
destructor that flips the status bit of the transmitted frame back to
available, allowing the transmitting task to complete).

However, when the calling application is SCHED_FIFO, its priority is
such that the schedule call immediately places the task back on the cpu,
preventing ksoftirqd from freeing the skb, which in turn prevents the
transmitting task from detecting that the transmission is complete.

We can fix this by converting the schedule call to a completion
mechanism. By using a completion queue, we force the calling task, when
it detects there are no more frames to send, to schedule itself off the
cpu until such time as the last transmitted skb is freed, allowing
forward progress to be made.

Tested by myself and the reporter, with good results

Change Notes:

V1->V2:
Enhance the sleep logic to support being interruptible and
allowing for honoring to SK_SNDTIMEO (Willem de Bruijn)

V2->V3:
Rearrage the point at which we wait for the completion queue, to
avoid needing to check for ph/skb being null at the end of the loop.
Also move the complete call to the skb destructor to avoid needing to
modify __packet_set_status. Also gate calling complete on
packet_read_pending returning zero to avoid multiple calls to complete.
(Willem de Bruijn)

Move timeo computation within loop, to re-fetch the socket
timeout since we also use the timeo variable to record the return code
from the wait_for_complete call (Neil Horman)

V3->V4:
Willem has requested that the control flow be restored to the
previous state. Doing so lets us eliminate the need for the
po->wait_on_complete flag variable, and lets us get rid of the
packet_next_frame function, but introduces another complexity.
Specifically, but using the packet pending count, we can, if an
applications calls sendmsg multiple times with MSG_DONTWAIT set, each
set of transmitted frames, when complete, will cause
tpacket_destruct_skb to issue a complete call, for which there will
never be a wait_on_completion call. This imbalance will lead to any
future call to wait_for_completion here to return early, when the frames
they sent may not have completed. To correct this, we need to re-init
the completion queue on every call to tpacket_snd before we enter the
loop so as to ensure we wait properly for the frames we send in this
iteration.

Change the timeout and interrupted gotos to out_put rather than
out_status so that we don't try to free a non-existant skb
Clean up some extra newlines (Willem de Bruijn)

Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: fix memory leak in packet_set_ring()

syzbot found we can leak memory in packet_set_ring(), if user application
provides buggy parameters.

Fixes: 7f953ab2ba46 ("af_packet: TX_RING support for TPACKET_V3")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: introduce packet_rcv_try_clear_pressure() helper

There are two places where we want to clear the pressure
if possible, add a helper to make it more obvious.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Willem de Bruijn <willemb@google.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: remove locking from packet_rcv_has_room()

__packet_rcv_has_room() can now be run without lock being held.

po->pressure is only a non persistent hint, we can mark
all read/write accesses with READ_ONCE()/WRITE_ONCE()
to document the fact that the field could be written
without any synchronization.

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

net/packet: implement shortcut in tpacket_rcv()

tpacket_rcv() can be hit under DDOS quite hard, since
it will always grab a socket spinlock, to eventually find
there is no room for an additional packet.

Using tcpdump [1] on a busy host can lead to catastrophic consequences,
because of all cpus spinning on a contended spinlock.

This replicates a similar strategy used in packet_rcv()

[1] Also some applications mistakenly use af_packet socket
bound to ETH_P_ALL only to send packets.
Receive queue is never drained and immediately full.

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

net/packet: make tp_drops atomic

Under DDOS, we want to be able to increment tp_drops without
touching the spinlock. This will help readers to drain
the receive queue slightly faster :/

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

net/packet: constify __packet_rcv_has_room()

Goal is use the helper without lock being held.

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

net/packet: constify prb_lookup_block() and __tpacket_v3_has_room()

Goal is to be able to use __tpacket_v3_has_room() without holding
a lock.

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

net/packet: constify packet_lookup_frame() and __tpacket_has_room()

Goal is to be able to use __tpacket_has_room() without holding a lock.

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

net/packet: constify __packet_get_status() argument

struct packet_sock is only read.

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

packet: remove unused variable 'status' in __packet_lookup_frame_in_block

The variable 'status' in __packet_lookup_frame_in_block() is never used since
introduction in commit f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer
implementation."), we can remove it.

Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: unconditionally free po->rollover

Rollover used to use a complex RCU mechanism for assignment, which had
a race condition. The below patch fixed the bug and greatly simplified
the logic.

The feature depends on fanout, but the state is private to the socket.
Fanout_release returns f only when the last member leaves and the
fanout struct is to be freed.

Destroy rollover unconditionally, regardless of fanout state.

Fixes: 57f015f5eccf2 ("packet: fix crash in fanout_demux_rollover()")
Reported-by: syzbot <syzkaller@googlegroups.com>
Diagnosed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.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>

packet: Fix error path in packet_init

kernel BUG at lib/list_debug.c:47!
invalid opcode: 0000 [#1
CPU: 0 PID: 12914 Comm: rmmod Tainted: G W 5.1.0+ #47
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:__list_del_entry_valid+0x53/0x90
Code: 48 8b 32 48 39 fe 75 35 48 8b 50 08 48 39 f2 75 40 b8 01 00 00 00 5d c3 48
89 fe 48 89 c2 48 c7 c7 18 75 fe 82 e8 cb 34 78 ff <0f> 0b 48 89 fe 48 c7 c7 50 75 fe 82 e8 ba 34 78 ff 0f 0b 48 89 f2
RSP: 0018:ffffc90001c2fe40 EFLAGS: 00010286
RAX: 000000000000004e RBX: ffffffffa0184000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff888237a17788 RDI: 00000000ffffffff
RBP: ffffc90001c2fe40 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90001c2fe10 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc90001c2fe50 R14: ffffffffa0184000 R15: 0000000000000000
FS: 00007f3d83634540(0000) GS:ffff888237a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555c350ea818 CR3: 0000000231677000 CR4: 00000000000006f0
Call Trace:
unregister_pernet_operations+0x34/0x120
unregister_pernet_subsys+0x1c/0x30
packet_exit+0x1c/0x369 [af_packet
__x64_sys_delete_module+0x156/0x260
? lockdep_hardirqs_on+0x133/0x1b0
? do_syscall_64+0x12/0x1f0
do_syscall_64+0x6e/0x1f0
entry_SYSCALL_64_after_hwframe+0x49/0xbe

When modprobe af_packet, register_pernet_subsys
fails and does a cleanup, ops->list is set to LIST_POISON1,
but the module init is considered to success, then while rmmod it,
BUG() is triggered in __list_del_entry_valid which is called from
unregister_pernet_subsys. This patch fix error handing path in
packet_init to avoid possilbe issue if some error occur.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: validate msg_namelen in send directly

Packet sockets in datagram mode take a destination address. Verify its
length before passing to dev_hard_header.

Prior to 2.6.14-rc3, the send code ignored sll_halen. This is
established behavior. Directly compare msg_namelen to dev->addr_len.

Change v1->v2: initialize addr in all paths

Fixes: 6b8d95f1795c4 ("packet: validate address length if non-zero")
Suggested-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: in recvmsg msg_name return at least sizeof sockaddr_ll

Packet send checks that msg_name is at least sizeof sockaddr_ll.
Packet recv must return at least this length, so that its output
can be passed unmodified to packet send.

This ceased to be true since adding support for lladdr longer than
sll_addr. Since, the return value uses true address length.

Always return at least sizeof sockaddr_ll, even if address length
is shorter. Zero the padding bytes.

Change v1->v2: do not overwrite zeroed padding again. use copy_len.

Fixes: 0fb375fb9b93 ("[AF_PACKET]: Allow for > 8 byte hardware addresses.")
Suggested-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: rework SIOCGSTAMP ioctl handling

The SIOCGSTAMP/SIOCGSTAMPNS ioctl commands are implemented by many
socket protocol handlers, and all of those end up calling the same
sock_get_timestamp()/sock_get_timestampns() helper functions, which
results in a lot of duplicate code.

With the introduction of 64-bit time_t on 32-bit architectures, this
gets worse, as we then need four different ioctl commands in each
socket protocol implementation.

To simplify that, let's add a new .gettstamp() operation in
struct proto_ops, and move ioctl implementation into the common
sock_ioctl()/compat_sock_ioctl_trans() functions that these all go
through.

We can reuse the sock_get_timestamp() implementation, but generalize
it so it can deal with both native and compat mode, as well as
timeval and timespec structures.

Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/lkml/CAK8P3a038aDQQotzua_QtKGhq8O9n+rdiz2=WDCp82ys8eUT+A@mail.gmail.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: remove 'fallback' argument from dev->ndo_select_queue()

After the previous patch, all the callers of ndo_select_queue()
provide as a 'fallback' argument netdev_pick_tx.
The only exceptions are nested calls to ndo_select_queue(),
which pass down the 'fallback' available in the current scope
- still netdev_pick_tx.

We can drop such argument and replace fallback() invocation with
netdev_pick_tx(). This avoids an indirect call per xmit packet
in some scenarios (TCP syn, UDP unconnected, XDP generic, pktgen)
with device drivers implementing such ndo. It also clean the code
a bit.

Tested with ixgbe and CONFIG_FCOE=m

With pktgen using queue xmit:
threads vanilla patched
(kpps) (kpps)
1 2334 2428
2 4166 4278
4 7895 8100

v1 -> v2:
- rebased after helper's name change

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: rework packet_pick_tx_queue() to use common code selection

Currently packet_pick_tx_queue() is the only caller of
ndo_select_queue() using a fallback argument other than
netdev_pick_tx.

Leveraging rx queue, we can obtain a similar queue selection
behavior using core helpers. After this change, ndo_select_queue()
is always invoked with netdev_pick_tx() as fallback.
We can change ndo_select_queue() signature in a followup patch,
dropping an indirect call per transmitted packet in some scenarios
(e.g. TCP syn and XDP generic xmit)

This changes slightly how af packet queue selection happens when
PACKET_QDISC_BYPASS is set. It's now more similar to plan dev_queue_xmit()
tacking in account both XPS and TC mapping.

v1 -> v2:
- rebased after helper name change
RFC -> v1:
- initialize sender_cpu to the expected value

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Set __GFP_NOWARN upon allocation in alloc_pg_vec

Since commit fc62814d690c ("net/packet: fix 4gb buffer limit due to overflow check")
one can now allocate packet ring buffers >= UINT_MAX. However, syzkaller
found that that triggers a warning:

[ 21.100000] WARNING: CPU: 2 PID: 2075 at mm/page_alloc.c:4584 __alloc_pages_nod0
[ 21.101490] Modules linked in:
[ 21.101921] CPU: 2 PID: 2075 Comm: syz-executor.0 Not tainted 5.0.0 #146
[ 21.102784] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.5.1 01/01/2011
[ 21.103887] RIP: 0010:__alloc_pages_nodemask+0x2a0/0x630
[ 21.104640] Code: fe ff ff 65 48 8b 04 25 c0 de 01 00 48 05 90 0f 00 00 41 bd 01 00 00 00 48 89 44 24 48 e9 9c fe 3
[ 21.107121] RSP: 0018:ffff88805e1cf920 EFLAGS: 00010246
[ 21.107819] RAX: 0000000000000000 RBX: ffffffff85a488a0 RCX: 0000000000000000
[ 21.108753] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000000
[ 21.109699] RBP: 1ffff1100bc39f28 R08: ffffed100bcefb67 R09: ffffed100bcefb67
[ 21.110646] R10: 0000000000000001 R11: ffffed100bcefb66 R12: 000000000000000d
[ 21.111623] R13: 0000000000000000 R14: ffff88805e77d888 R15: 000000000000000d
[ 21.112552] FS: 00007f7c7de05700(0000) GS:ffff88806d100000(0000) knlGS:0000000000000000
[ 21.113612] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 21.114405] CR2: 000000000065c000 CR3: 000000005e58e006 CR4: 00000000001606e0
[ 21.115367] Call Trace:
[ 21.115705] ? __alloc_pages_slowpath+0x21c0/0x21c0
[ 21.116362] alloc_pages_current+0xac/0x1e0
[ 21.116923] kmalloc_order+0x18/0x70
[ 21.117393] kmalloc_order_trace+0x18/0x110
[ 21.117949] packet_set_ring+0x9d5/0x1770
[ 21.118524] ? packet_rcv_spkt+0x440/0x440
[ 21.119094] ? lock_downgrade+0x620/0x620
[ 21.119646] ? __might_fault+0x177/0x1b0
[ 21.120177] packet_setsockopt+0x981/0x2940
[ 21.120753] ? __fget+0x2fb/0x4b0
[ 21.121209] ? packet_release+0xab0/0xab0
[ 21.121740] ? sock_has_perm+0x1cd/0x260
[ 21.122297] ? selinux_secmark_relabel_packet+0xd0/0xd0
[ 21.123013] ? __fget+0x324/0x4b0
[ 21.123451] ? selinux_netlbl_socket_setsockopt+0x101/0x320
[ 21.124186] ? selinux_netlbl_sock_rcv_skb+0x3a0/0x3a0
[ 21.124908] ? __lock_acquire+0x529/0x3200
[ 21.125453] ? selinux_socket_setsockopt+0x5d/0x70
[ 21.126075] ? __sys_setsockopt+0x131/0x210
[ 21.126533] ? packet_release+0xab0/0xab0
[ 21.127004] __sys_setsockopt+0x131/0x210
[ 21.127449] ? kernel_accept+0x2f0/0x2f0
[ 21.127911] ? ret_from_fork+0x8/0x50
[ 21.128313] ? do_raw_spin_lock+0x11b/0x280
[ 21.128800] __x64_sys_setsockopt+0xba/0x150
[ 21.129271] ? lockdep_hardirqs_on+0x37f/0x560
[ 21.129769] do_syscall_64+0x9f/0x450
[ 21.130182] entry_SYSCALL_64_after_hwframe+0x49/0xbe

We should allocate with __GFP_NOWARN to handle this.

Cc: Kal Conley <kal.conley@dectris.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Fixes: fc62814d690c ("net/packet: fix 4gb buffer limit due to overflow check")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: fix the tx skb protocol in raw sockets with ETH_P_ALL

I am using "protocol ip" filters in TC to manipulate TC flower
classifiers, which are only available with "protocol ip". However,
I faced an issue that packets sent via raw sockets with ETH_P_ALL
did not match the ip filters even if they did satisfy the condition
(e.g., DHCP offer from dhcpd).

I have determined that the behavior was caused by an unexpected
value stored in skb->protocol, namely, ETH_P_ALL instead of ETH_P_IP,
when packets were sent via raw sockets with ETH_P_ALL set.

IMHO, storing ETH_P_ALL in skb->protocol is not appropriate for
packets sent via raw sockets because ETH_P_ALL is not a real ether
type used on wire, but a virtual one.

This patch fixes the tx protocol selection in cases of transmission
via raw sockets created with ETH_P_ALL so that it asks the driver to
extract protocol from the Ethernet header.

Fixes: 75c65772c3 ("net/packet: Ask driver for protocol if not provided by user")
Signed-off-by: Yoshiki Komachi <komachi.yoshiki@lab.ntt.co.jp>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packets: Always register packet sk in the same order

When using fanouts with AF_PACKET, the demux functions such as
fanout_demux_cpu will return an index in the fanout socket array, which
corresponds to the selected socket.

The ordering of this array depends on the order the sockets were added
to a given fanout group, so for FANOUT_CPU this means sockets are bound
to cpus in the order they are configured, which is OK.

However, when stopping then restarting the interface these sockets are
bound to, the sockets are reassigned to the fanout group in the reverse
order, due to the fact that they were inserted at the head of the
interface's AF_PACKET socket list.

This means that traffic that was directed to the first socket in the
fanout group is now directed to the last one after an interface restart.

In the case of FANOUT_CPU, traffic from CPU0 will be directed to the
socket that used to receive traffic from the last CPU after an interface
restart.

This commit introduces a helper to add a socket at the tail of a list,
then uses it to register AF_PACKET sockets.

Note that this changes the order in which sockets are listed in /proc and
with sock_diag.

Fixes: dc99f600698d ("packet: Add fanout support")
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Remove redundant skb->protocol set

c72219b75f introduced tpacket_set_protocol that parses the Ethernet L2
header and sets skb->protocol if it's unset. It is no longer needed
since the introduction of packet_parse_headers. In case of SOCK_RAW and
unset skb->protocol, packet_parse_headers asks the driver to tell the
protocol number, and it's implemented for all Ethernet devices. As the
old function supported only Ethernet, no functionality is lost.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Ask driver for protocol if not provided by user

If a socket was created with socket(AF_PACKET, SOCK_RAW, 0), the
protocol number is unavailable. Try to ask the driver to extract it from
the L2 header in order for skb_try_probe_transport_header to succeed.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Don't set transport offset to invalid value

If the socket was created with socket(AF_PACKET, SOCK_RAW, 0),
skb->protocol will be unset, __skb_flow_dissect() will fail, and
skb_probe_transport_header() will fall back to the offset_hint, making
the resulting skb_transport_offset incorrect.

If, however, there is no transport header in the packet,
transport_header shouldn't be set to an arbitrary value.

Fix it by leaving the transport offset unset if it couldn't be found, to
be explicit rather than to fill it with some wrong value. It changes the
behavior, but if some code relied on the old behavior, it would be
broken anyway, as the old one is incorrect.

Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: fix 4gb buffer limit due to overflow check

When calculating rb->frames_per_block * req->tp_block_nr the result
can overflow. Check it for overflow without limiting the total buffer
size to UINT_MAX.

This change fixes support for packet ring buffers >= UINT_MAX.

Fixes: 8f8d28e4d6d8 ("net/packet: fix overflow in check for tp_frame_nr")
Signed-off-by: Kal Conley <kal.conley@dectris.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: fix raw sockets over 6in4 tunnel

Since commit cb9f1b783850, scapy (which uses an AF_PACKET socket in
SOCK_RAW mode) is unable to send a basic icmp packet over a sit tunnel:

Here is a example of the setup:
$ ip link set ntfp2 up
$ ip addr add 10.125.0.1/24 dev ntfp2
$ ip tunnel add tun1 mode sit ttl 64 local 10.125.0.1 remote 10.125.0.2 dev ntfp2
$ ip addr add fd00:cafe:cafe::1/128 dev tun1
$ ip link set dev tun1 up
$ ip route add fd00:200::/64 dev tun1
$ scapy
>>> p = []
>>> p += IPv6(src='fd00:100::1', dst='fd00:200::1')/ICMPv6EchoRequest()
>>> send(p, count=1, inter=0.1)
>>> quit()
$ ip -s link ls dev tun1 | grep -A1 "TX.*errors"
TX: bytes packets errors dropped carrier collsns
0 0 1 0 0 0

The problem is that the network offset is set to the hard_header_len of the
output device (tun1, ie 14 + 20) and in our case, because the packet is
small (48 bytes) the pskb_inet_may_pull() fails (it tries to pull 40 bytes
(ipv6 header) starting from the network offset).

This problem is more generally related to device with variable hard header
length. To avoid a too intrusive patch in the current release, a (ugly)
workaround is proposed in this patch. It has to be cleaned up in net-next.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=993675a3100b1
Link: http://patchwork.ozlabs.org/patch/1024489/
Fixes: cb9f1b783850 ("ip: validate header length on virtual device xmit")
CC: Willem de Bruijn <willemb@google.com>
CC: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: Do not leak dev refcounts on error exit

'dev' is non NULL when the addr_len check triggers so it must goto a label
that does the dev_put otherwise dev will have a leaked refcount.

This bug causes the ib_ipoib module to become unloadable when using
systemd-network as it triggers this check on InfiniBand links.

Fixes: 99137b7888f4 ("packet: validate address length")
Reported-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: validate address length if non-zero

Validate packet socket address length if a length is given. Zero
length is equivalent to not setting an address.

Fixes: 99137b7888f4 ("packet: validate address length")
Reported-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: validate address length

Packet sockets with SOCK_DGRAM may pass an address for use in
dev_hard_header. Ensure that it is of sufficient length.

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: add missing SOF_TIMESTAMPING_OPT_ID support

SOF_TIMESTAMPING_OPT_ID is supported on TCP, UDP and RAW sockets.
But it was missing on RAW with IPPROTO_IP, PF_PACKET and CAN.

Add skb_setup_tx_timestamp that configures both tx_flags and tskey
for these paths that do not need corking or use bytestream keys.

Fixes: 09c2d251b707 ("net-timestamp: add key to disambiguate concurrent datagrams")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: copy user buffers before orphan or clone

tpacket_snd sends packets with user pages linked into skb frags. It
notifies that pages can be reused when the skb is released by setting
skb->destructor to tpacket_destruct_skb.

This can cause data corruption if the skb is orphaned (e.g., on
transmit through veth) or cloned (e.g., on mirror to another psock).

Create a kernel-private copy of data in these cases, same as tun/tap
zerocopy transmission. Reuse that infrastructure: mark the skb as
SKBTX_ZEROCOPY_FRAG, which will trigger copy in skb_orphan_frags(_rx).

Unlike other zerocopy packets, do not set shinfo destructor_arg to
struct ubuf_info. tpacket_destruct_skb already uses that ptr to notify
when the original skb is released and a timestamp is recorded. Do not
change this timestamp behavior. The ubuf_info->callback is not needed
anyway, as no zerocopy notification is expected.

Mark destructor_arg as not-a-uarg by setting the lower bit to 1. The
resulting value is not a valid ubuf_info pointer, nor a valid
tpacket_snd frame address. Add skb_zcopy_.._nouarg helpers for this.

The fix relies on features introduced in commit 52267790ef52 ("sock:
add MSG_ZEROCOPY"), so can be backported as is only to 4.14.

Tested with from `./in_netns.sh ./txring_overwrite` from
http://github.com/wdebruij/kerneltools/tests

Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap")
Reported-by: Anand H. Krishnan <anandhkrishnan@gmail.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: fix packet drop as of virtio gso

When we use raw socket as the vhost backend, a packet from virito with
gso offloading information, cannot be sent out in later validaton at
xmit path, as we did not set correct skb->protocol which is further used
for looking up the gso function.

To fix this, we set this field according to virito hdr information.

Fixes: e858fae2b0b8f4 ("virtio_net: use common code for virtio_net_hdr and skb GSO conversion")
Signed-off-by: Jianfeng Tan <jianfeng.tan@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: add sockopt to ignore outgoing packets

Currently, the only way to ignore outgoing packets on a packet socket is
via the BPF filter. With MSG_ZEROCOPY, packets that are looped into
AF_PACKET are copied in dev_queue_xmit_nit(), and this copy happens even
if the filter run from packet_rcv() would reject them. So the presence
of a packet socket on the interface takes away the benefits of
MSG_ZEROCOPY, even if the packet socket is not interested in outgoing
packets. (Even when MSG_ZEROCOPY is not used, the skb is unnecessarily
cloned, but the cost for that is much lower.)

Add a socket option to allow AF_PACKET sockets to ignore outgoing
packets to solve this. Note that the *BSDs already have something
similar: BIOCSSEESENT/BIOCSDIRECTION and BIOCSDIRFILT.

The first intended user is lldpd.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Revert "packet: switch kvzalloc to allocate memory"

This reverts commit 71e41286203c017d24f041a7cd71abea7ca7b1e0.

mmap()/munmap() can not be backed by kmalloced pages :

We fault in :

VM_BUG_ON_PAGE(PageSlab(page), page);

unmap_single_vma+0x8a/0x110
unmap_vmas+0x4b/0x90
unmap_region+0xc9/0x140
do_munmap+0x274/0x360
vm_munmap+0x81/0xc0
SyS_munmap+0x2b/0x40
do_syscall_64+0x13e/0x1c0
entry_SYSCALL_64_after_hwframe+0x42/0xb7

Fixes: 71e41286203c ("packet: switch kvzalloc to allocate memory")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: John Sperbeck <jsperbeck@google.com>
Bisected-by: John Sperbeck <jsperbeck@google.com>
Cc: Zhang Yu <zhangyu31@baidu.com>
Cc: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: switch kvzalloc to allocate memory

The patches includes following change:

*Use modern kvzalloc()/kvfree() instead of custom allocations.

*Remove order argument for alloc_pg_vec, it can get from req.

*Remove order argument for free_pg_vec, free_pg_vec now uses
kvfree which does not need order argument.

*Remove pg_vec_order from struct packet_ring_buffer, no longer
need to save/restore 'order'

*Remove variable 'order' for packet_set_ring, it is now unused

Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: refine ring v3 block size test to hold one frame

TPACKET_V3 stores variable length frames in fixed length blocks.
Blocks must be able to store a block header, optional private space
and at least one minimum sized frame.

Frames, even for a zero snaplen packet, store metadata headers and
optional reserved space.

In the block size bounds check, ensure that the frame of the
chosen configuration fits. This includes sockaddr_ll and optional
tp_reserve.

Syzbot was able to construct a ring with insuffient room for the
sockaddr_ll in the header of a zero-length frame, triggering an
out-of-bounds write in dev_parse_header.

Convert the comparison to less than, as zero is a valid snap len.
This matches the test for minimum tp_frame_size immediately below.

Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.")
Fixes: eb73190f4fbe ("net/packet: refine check for priv area size")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Remove some unneeded semicolon

These semicolons are not needed. Just remove them.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: reset network header if packet shorter than ll reserved space

If variable length link layer headers result in a packet shorter
than dev->hard_header_len, reset the network header offset. Else
skb->mac_len may exceed skb->len after skb_mac_reset_len.

packet_sendmsg_spkt already has similar logic.

Fixes: b84bbaf7a6c8 ("packet: in packet_snd start writing at link layer allocation")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: allow fallback function to pass netdev

For most of these calls we can just pass NULL through to the fallback
function as the sb_dev. The only cases where we cannot are the cases where
we might be dealing with either an upper device or a driver that would
have configured things to support an sb_dev itself.

The only driver that has any significant change in this patch set should be
ixgbe as we can drop the redundant functionality that existed in both the
ndo_select_queue function and the fallback function that was passed through
to us.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

net: Add generic ndo_select_queue functions

This patch adds a generic version of the ndo_select_queue functions for
either returning 0 or selecting a queue based on the processor ID. This is
generally meant to just reduce the number of functions we have to change
in the future when we have to deal with ndo_select_queue changes.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

sock: sockc cookie initializer

Initialize the cookie in one location to reduce code duplication and
avoid bugs from inconsistent initialization, such as that fixed in
commit 9887cba19978 ("ip: limit use of gso_size to udp").

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: packet: Hook into time based transmission.

For raw layer-2 packets, copy the desired future transmit time from
the CMSG cookie into the skb.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL

The poll() changes were not well thought out, and completely
unexplained. They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.

Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead. That gets rid of one of the new indirections.

But that doesn't fix the new complexity that is completely unwarranted
for the regular case. The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.

[ This revert is a revert of about 30 different commits, not reverted
individually because that would just be unnecessarily messy - Linus ]

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net/packet: fix use-after-free

We should put copy_skb in receive_queue only after
a successful call to virtio_net_hdr_from_skb().

syzbot report :

BUG: KASAN: use-after-free in __skb_unlink include/linux/skbuff.h:1843 [inline]
BUG: KASAN: use-after-free in __skb_dequeue include/linux/skbuff.h:1863 [inline]
BUG: KASAN: use-after-free in skb_dequeue+0x16a/0x180 net/core/skbuff.c:2815
Read of size 8 at addr ffff8801b044ecc0 by task syz-executor217/4553

CPU: 0 PID: 4553 Comm: syz-executor217 Not tainted 4.18.0-rc1+ #111
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+0x1c9/0x2b4 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
__skb_unlink include/linux/skbuff.h:1843 [inline]
__skb_dequeue include/linux/skbuff.h:1863 [inline]
skb_dequeue+0x16a/0x180 net/core/skbuff.c:2815
skb_queue_purge+0x26/0x40 net/core/skbuff.c:2852
packet_set_ring+0x675/0x1da0 net/packet/af_packet.c:4331
packet_release+0x630/0xd90 net/packet/af_packet.c:2991
__sock_release+0xd7/0x260 net/socket.c:603
sock_close+0x19/0x20 net/socket.c:1186
__fput+0x35b/0x8b0 fs/file_table.c:209
____fput+0x15/0x20 fs/file_table.c:243
task_work_run+0x1ec/0x2a0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x1b08/0x2750 kernel/exit.c:865
do_group_exit+0x177/0x440 kernel/exit.c:968
__do_sys_exit_group kernel/exit.c:979 [inline]
__se_sys_exit_group kernel/exit.c:977 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:977
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4448e9
Code: Bad RIP value.
RSP: 002b:00007ffd5f777ca8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00000000004448e9
RDX: 00000000004448e9 RSI: 000000000000fcfb RDI: 0000000000000001
RBP: 00000000006cf018 R08: 00007ffd0000a45b R09: 0000000000000000
R10: 00007ffd5f777e48 R11: 0000000000000202 R12: 00000000004021f0
R13: 0000000000402280 R14: 0000000000000000 R15: 0000000000000000

Allocated by task 4553:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
skb_clone+0x1f5/0x500 net/core/skbuff.c:1282
tpacket_rcv+0x28f7/0x3200 net/packet/af_packet.c:2221
deliver_skb net/core/dev.c:1925 [inline]
deliver_ptype_list_skb net/core/dev.c:1940 [inline]
__netif_receive_skb_core+0x1bfb/0x3680 net/core/dev.c:4611
__netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4693
netif_receive_skb_internal+0x12e/0x7d0 net/core/dev.c:4767
netif_receive_skb+0xbf/0x420 net/core/dev.c:4791
tun_rx_batched.isra.55+0x4ba/0x8c0 drivers/net/tun.c:1571
tun_get_user+0x2af1/0x42f0 drivers/net/tun.c:1981
tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:2009
call_write_iter include/linux/fs.h:1795 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x6c6/0x9f0 fs/read_write.c:487
vfs_write+0x1f8/0x560 fs/read_write.c:549
ksys_write+0x101/0x260 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 4553:
save_stack+0x43/0xd0 mm/kasan/kasan.c:448
set_track mm/kasan/kasan.c:460 [inline]
__kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
__cache_free mm/slab.c:3498 [inline]
kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
kfree_skbmem+0x154/0x230 net/core/skbuff.c:582
__kfree_skb net/core/skbuff.c:642 [inline]
kfree_skb+0x1a5/0x580 net/core/skbuff.c:659
tpacket_rcv+0x189e/0x3200 net/packet/af_packet.c:2385
deliver_skb net/core/dev.c:1925 [inline]
deliver_ptype_list_skb net/core/dev.c:1940 [inline]
__netif_receive_skb_core+0x1bfb/0x3680 net/core/dev.c:4611
__netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4693
netif_receive_skb_internal+0x12e/0x7d0 net/core/dev.c:4767
netif_receive_skb+0xbf/0x420 net/core/dev.c:4791
tun_rx_batched.isra.55+0x4ba/0x8c0 drivers/net/tun.c:1571
tun_get_user+0x2af1/0x42f0 drivers/net/tun.c:1981
tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:2009
call_write_iter include/linux/fs.h:1795 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x6c6/0x9f0 fs/read_write.c:487
vfs_write+0x1f8/0x560 fs/read_write.c:549
ksys_write+0x101/0x260 fs/read_write.c:598
__do_sys_write fs/read_write.c:610 [inline]
__se_sys_write fs/read_write.c:607 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:607
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801b044ecc0
which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 0 bytes inside of
232-byte region [ffff8801b044ecc0, ffff8801b044eda8)
The buggy address belongs to the page:
page:ffffea0006c11380 count:1 mapcount:0 mapping:ffff8801d9be96c0 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea0006c17988 ffff8801d9bec248 ffff8801d9be96c0
raw: 0000000000000000 ffff8801b044e040 000000010000000c 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8801b044eb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8801b044ec00: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
>ffff8801b044ec80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
^
ffff8801b044ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8801b044ed80: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc

Fixes: 58d19b19cd99 ("packet: vnet_hdr support for tpacket_rcv")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

treewide: Use array_size() in vzalloc()

The vzalloc() function has no 2-factor argument form, so multiplication
factors need to be wrapped in array_size(). This patch replaces cases of:

vzalloc(a * b)

with:
vzalloc(array_size(a, b))

as well as handling cases of:

vzalloc(a * b * c)

with:

vzalloc(array3_size(a, b, c))

This does, however, attempt to ignore constant size factors like:

vzalloc(4 * 1024)

though any constants defined via macros get caught up in the conversion.

Any factors with a sizeof() of "unsigned char", "char", and "u8" were
dropped, since they're redundant.

The Coccinelle script used for this was:

// Fix redundant parens around sizeof().
@@
type TYPE;
expression THING, E;
@@

(
vzalloc(
- (sizeof(TYPE)) * E
+ sizeof(TYPE) * E
, ...)
|
vzalloc(
- (sizeof(THING)) * E
+ sizeof(THING) * E
, ...)
)

// Drop single-byte sizes and redundant parens.
@@
expression COUNT;
typedef u8;
typedef __u8;
@@

(
vzalloc(
- sizeof(u8) * (COUNT)
+ COUNT
, ...)
|
vzalloc(
- sizeof(__u8) * (COUNT)
+ COUNT
, ...)
|
vzalloc(
- sizeof(char) * (COUNT)
+ COUNT
, ...)
|
vzalloc(
- sizeof(unsigned char) * (COUNT)
+ COUNT
, ...)
|
vzalloc(
- sizeof(u8) * COUNT
+ COUNT
, ...)
|
vzalloc(
- sizeof(__u8) * COUNT
+ COUNT
, ...)
|
vzalloc(
- sizeof(char) * COUNT
+ COUNT
, ...)
|
vzalloc(
- sizeof(unsigned char) * COUNT
+ COUNT
, ...)
)

// 2-factor product with sizeof(type/expression) and identifier or constant.
@@
type TYPE;
expression THING;
identifier COUNT_ID;
constant COUNT_CONST;
@@

(
vzalloc(
- sizeof(TYPE) * (COUNT_ID)
+ array_size(COUNT_ID, sizeof(TYPE))
, ...)
|
vzalloc(
- sizeof(TYPE) * COUNT_ID
+ array_size(COUNT_ID, sizeof(TYPE))
, ...)
|
vzalloc(
- sizeof(TYPE) * (COUNT_CONST)
+ array_size(COUNT_CONST, sizeof(TYPE))
, ...)
|
vzalloc(
- sizeof(TYPE) * COUNT_CONST
+ array_size(COUNT_CONST, sizeof(TYPE))
, ...)
|
vzalloc(
- sizeof(THING) * (COUNT_ID)
+ array_size(COUNT_ID, sizeof(THING))
, ...)
|
vzalloc(
- sizeof(THING) * COUNT_ID
+ array_size(COUNT_ID, sizeof(THING))
, ...)
|
vzalloc(
- sizeof(THING) * (COUNT_CONST)
+ array_size(COUNT_CONST, sizeof(THING))
, ...)
|
vzalloc(
- sizeof(THING) * COUNT_CONST
+ array_size(COUNT_CONST, sizeof(THING))
, ...)
)

// 2-factor product, only identifiers.
@@
identifier SIZE, COUNT;
@@

vzalloc(
- SIZE * COUNT
+ array_size(COUNT, SIZE)
, ...)

// 3-factor product with 1 sizeof(type) or sizeof(expression), with
// redundant parens removed.
@@
expression THING;
identifier STRIDE, COUNT;
type TYPE;
@@

(
vzalloc(
- sizeof(TYPE) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
vzalloc(
- sizeof(TYPE) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
vzalloc(
- sizeof(TYPE) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
vzalloc(
- sizeof(TYPE) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(TYPE))
, ...)
|
vzalloc(
- sizeof(THING) * (COUNT) * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
vzalloc(
- sizeof(THING) * (COUNT) * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
vzalloc(
- sizeof(THING) * COUNT * (STRIDE)
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
|
vzalloc(
- sizeof(THING) * COUNT * STRIDE
+ array3_size(COUNT, STRIDE, sizeof(THING))
, ...)
)

// 3-factor product with 2 sizeof(variable), with redundant parens removed.
@@
expression THING1, THING2;
identifier COUNT;
type TYPE1, TYPE2;
@@

(
vzalloc(
- sizeof(TYPE1) * sizeof(TYPE2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
vzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2))
, ...)
|
vzalloc(
- sizeof(THING1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
vzalloc(
- sizeof(THING1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(THING1), sizeof(THING2))
, ...)
|
vzalloc(
- sizeof(TYPE1) * sizeof(THING2) * COUNT
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
|
vzalloc(
- sizeof(TYPE1) * sizeof(THING2) * (COUNT)
+ array3_size(COUNT, sizeof(TYPE1), sizeof(THING2))
, ...)
)

// 3-factor product, only identifiers, with redundant parens removed.
@@
identifier STRIDE, SIZE, COUNT;
@@

(
vzalloc(
- (COUNT) * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
vzalloc(
- COUNT * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
vzalloc(
- COUNT * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
vzalloc(
- (COUNT) * (STRIDE) * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
vzalloc(
- COUNT * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
vzalloc(
- (COUNT) * STRIDE * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
vzalloc(
- (COUNT) * (STRIDE) * (SIZE)
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
|
vzalloc(
- COUNT * STRIDE * SIZE
+ array3_size(COUNT, STRIDE, SIZE)
, ...)
)

// Any remaining multi-factor products, first at least 3-factor products
// when they're not all constants...
@@
expression E1, E2, E3;
constant C1, C2, C3;
@@

(
vzalloc(C1 * C2 * C3, ...)
|
vzalloc(
- E1 * E2 * E3
+ array3_size(E1, E2, E3)
, ...)
)

// And then all remaining 2 factors products when they're not all constants.
@@
expression E1, E2;
constant C1, C2;
@@

(
vzalloc(C1 * C2, ...)
|
vzalloc(
- E1 * E2
+ array_size(E1, E2)
, ...)
)

Signed-off-by: Kees Cook <keescook@chromium.org>

net: in virtio_net_hdr only add VLAN_HLEN to csum_start if payload holds vlan

Tun, tap, virtio, packet and uml vector all use struct virtio_net_hdr
to communicate packet metadata to userspace.

For skbuffs with vlan, the first two return the packet as it may have
existed on the wire, inserting the VLAN tag in the user buffer. Then
virtio_net_hdr.csum_start needs to be adjusted by VLAN_HLEN bytes.

Commit f09e2249c4f5 ("macvtap: restore vlan header on user read")
added this feature to macvtap. Commit 3ce9b20f1971 ("macvtap: Fix
csum_start when VLAN tags are present") then fixed up csum_start.

Virtio, packet and uml do not insert the vlan header in the user
buffer.

When introducing virtio_net_hdr_from_skb to deduplicate filling in
the virtio_net_hdr, the variant from macvtap which adds VLAN_HLEN was
applied uniformly, breaking csum offset for packets with vlan on
virtio and packet.

Make insertion of VLAN_HLEN optional. Convert the callers to pass it
when needed.

Fixes: e858fae2b0b8f4 ("virtio_net: use common code for virtio_net_hdr and skb GSO conversion")
Fixes: 1276f24eeef2 ("packet: use common code for virtio_net_hdr and skb GSO conversion")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: refine check for priv area size

syzbot was able to trick af_packet again [1]

Various commits tried to address the problem in the past,
but failed to take into account V3 header size.

[1]

tpacket_rcv: packet too big, clamped from 72 to 4294967224. macoff=96
BUG: KASAN: use-after-free in prb_run_all_ft_ops net/packet/af_packet.c:1016 [inline]
BUG: KASAN: use-after-free in prb_fill_curr_block.isra.59+0x4e5/0x5c0 net/packet/af_packet.c:1039
Write of size 2 at addr ffff8801cb62000e by task kworker/1:2/2106

CPU: 1 PID: 2106 Comm: kworker/1:2 Not tainted 4.17.0-rc7+ #77
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b9/0x294 lib/dump_stack.c:113
print_address_description+0x6c/0x20b mm/kasan/report.c:256
kasan_report_error mm/kasan/report.c:354 [inline]
kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
__asan_report_store2_noabort+0x17/0x20 mm/kasan/report.c:436
prb_run_all_ft_ops net/packet/af_packet.c:1016 [inline]
prb_fill_curr_block.isra.59+0x4e5/0x5c0 net/packet/af_packet.c:1039
__packet_lookup_frame_in_block net/packet/af_packet.c:1094 [inline]
packet_current_rx_frame net/packet/af_packet.c:1117 [inline]
tpacket_rcv+0x1866/0x3340 net/packet/af_packet.c:2282
dev_queue_xmit_nit+0x891/0xb90 net/core/dev.c:2018
xmit_one net/core/dev.c:3049 [inline]
dev_hard_start_xmit+0x16b/0xc10 net/core/dev.c:3069
__dev_queue_xmit+0x2724/0x34c0 net/core/dev.c:3584
dev_queue_xmit+0x17/0x20 net/core/dev.c:3617
neigh_resolve_output+0x679/0xad0 net/core/neighbour.c:1358
neigh_output include/net/neighbour.h:482 [inline]
ip6_finish_output2+0xc9c/0x2810 net/ipv6/ip6_output.c:120
ip6_finish_output+0x5fe/0xbc0 net/ipv6/ip6_output.c:154
NF_HOOK_COND include/linux/netfilter.h:277 [inline]
ip6_output+0x227/0x9b0 net/ipv6/ip6_output.c:171
dst_output include/net/dst.h:444 [inline]
NF_HOOK include/linux/netfilter.h:288 [inline]
ndisc_send_skb+0x100d/0x1570 net/ipv6/ndisc.c:491
ndisc_send_ns+0x3c1/0x8d0 net/ipv6/ndisc.c:633
addrconf_dad_work+0xbef/0x1340 net/ipv6/addrconf.c:4033
process_one_work+0xc1e/0x1b50 kernel/workqueue.c:2145
worker_thread+0x1cc/0x1440 kernel/workqueue.c:2279
kthread+0x345/0x410 kernel/kthread.c:240
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412

The buggy address belongs to the page:
page:ffffea00072d8800 count:0 mapcount:-127 mapping:0000000000000000 index:0xffff8801cb620e80
flags: 0x2fffc0000000000()
raw: 02fffc0000000000 0000000000000000 ffff8801cb620e80 00000000ffffff80
raw: ffffea00072e3820 ffffea0007132d20 0000000000000002 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8801cb61ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8801cb61ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801cb620000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff8801cb620080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8801cb620100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

Fixes: 2b6867c2ce76 ("net/packet: fix overflow in check for priv area size")
Fixes: dc808110bb62 ("packet: handle too big packets for PACKET_V3")
Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: convert datagram_poll users tp ->poll_mask

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

packet: fix reserve calculation

Commit b84bbaf7a6c8 ("packet: in packet_snd start writing at link
layer allocation") ensures that packet_snd always starts writing
the link layer header in reserved headroom allocated for this
purpose.

This is needed because packets may be shorter than hard_header_len,
in which case the space up to hard_header_len may be zeroed. But
that necessary padding is not accounted for in skb->len.

The fix, however, is buggy. It calls skb_push, which grows skb->len
when moving skb->data back. But in this case packet length should not
change.

Instead, call skb_reserve, which moves both skb->data and skb->tail
back, without changing length.

Fixes: b84bbaf7a6c8 ("packet: in packet_snd start writing at link layer allocation")
Reported-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

proc: introduce proc_create_net{,_data}

Variants of proc_create{,_data} that directly take a struct seq_operations
and deal with network namespaces in ->open and ->release. All callers of
proc_create + seq_open_net converted over, and seq_{open,release}_net are
removed entirely.

Signed-off-by: Christoph Hellwig <hch@lst.de>

packet: in packet_snd start writing at link layer allocation

Packet sockets allow construction of packets shorter than
dev->hard_header_len to accommodate protocols with variable length
link layer headers. These packets are padded to dev->hard_header_len,
because some device drivers interpret that as a minimum packet size.

packet_snd reserves dev->hard_header_len bytes on allocation.
SOCK_DGRAM sockets call skb_push in dev_hard_header() to ensure that
link layer headers are stored in the reserved range. SOCK_RAW sockets
do the same in tpacket_snd, but not in packet_snd.

Syzbot was able to send a zero byte packet to a device with massive
116B link layer header, causing padding to cross over into skb_shinfo.
Fix this by writing from the start of the llheader reserved range also
in the case of packet_snd/SOCK_RAW.

Update skb_set_network_header to the new offset. This also corrects
it for SOCK_DGRAM, where it incorrectly double counted reserve due to
the skb_push in dev_hard_header.

Fixes: 9ed988cd5915 ("packet: validate variable length ll headers")
Reported-by: syzbot+71d74a5406d02057d559@syzkaller.appspotmail.com
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

dev: packet: make packet_direct_xmit a common function

The new dev_direct_xmit will be used by AF_XDP in later commits.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

packet: fix bitfield update race

Updates to the bitfields in struct packet_sock are not atomic.
Serialize these read-modify-write cycles.

Move po->running into a separate variable. Its writes are protected by
po->bind_lock (except for one startup case at packet_create). Also
replace a textual precondition warning with lockdep annotation.

All others are set only in packet_setsockopt. Serialize these
updates by holding the socket lock. Analogous to other field updates,
also hold the lock when testing whether a ring is active (pg_vec).

Fixes: 8dc419447415 ("[PACKET]: Add optional checksum computation for recvmsg")
Reported-by: DaeRyong Jeong <threeearcat@gmail.com>
Reported-by: Byoungyoung Lee <byoungyoung@purdue.edu>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: af_packet: fix race in PACKET_{R|T}X_RING

In order to remove the race caught by syzbot [1], we need
to lock the socket before using po->tp_version as this could
change under us otherwise.

This means lock_sock() and release_sock() must be done by
packet_set_ring() callers.

[1] :
BUG: KMSAN: uninit-value in packet_set_ring+0x1254/0x3870 net/packet/af_packet.c:4249
CPU: 0 PID: 20195 Comm: syzkaller707632 Not tainted 4.16.0+ #83
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x185/0x1d0 lib/dump_stack.c:53
kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067
__msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676
packet_set_ring+0x1254/0x3870 net/packet/af_packet.c:4249
packet_setsockopt+0x12c6/0x5a90 net/packet/af_packet.c:3662
SYSC_setsockopt+0x4b8/0x570 net/socket.c:1849
SyS_setsockopt+0x76/0xa0 net/socket.c:1828
do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x449099
RSP: 002b:00007f42b5307ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 000000000070003c RCX: 0000000000449099
RDX: 0000000000000005 RSI: 0000000000000107 RDI: 0000000000000003
RBP: 0000000000700038 R08: 000000000000001c R09: 0000000000000000
R10: 00000000200000c0 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000080eecf R14: 00007f42b53089c0 R15: 0000000000000001

Local variable description: ----req_u@packet_setsockopt
Variable was created at:
packet_setsockopt+0x13f/0x5a90 net/packet/af_packet.c:3612
SYSC_setsockopt+0x4b8/0x570 net/socket.c:1849

Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.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: Convert packet_net_ops

These pernet_operations just create and destroy /proc entry,
and another operations do not touch it.

Also, nobody else are interested in foreign net::packet::sklist.

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: make getname() functions return length rather than use int* parameter

Changes since v1:
Added changes in these files:
drivers/infiniband/hw/usnic/usnic_transport.c
drivers/staging/lustre/lnet/lnet/lib-socket.c
drivers/target/iscsi/iscsi_target_login.c
drivers/vhost/net.c
fs/dlm/lowcomms.c
fs/ocfs2/cluster/tcp.c
security/tomoyo/network.c

Before:
All these functions either return a negative error indicator,
or store length of sockaddr into "int *socklen" parameter
and return zero on success.

"int *socklen" parameter is awkward. For example, if caller does not
care, it still needs to provide on-stack storage for the value
it does not need.

None of the many FOO_getname() functions of various protocols
ever used old value of *socklen. They always just overwrite it.

This change drops this parameter, and makes all these functions, on success,
return length of sockaddr. It's always >= 0 and can be differentiated
from an error.

Tests in callers are changed from "if (err)" to "if (err < 0)", where needed.

rpc_sockname() lost "int buflen" parameter, since its only use was
to be passed to kernel_getsockname() as &buflen and subsequently
not used in any way.

Userspace API is not changed.

text data bss dec hex filename
30108430 2633624 873672 33615726 200ef6e vmlinux.before.o
30108109 2633612 873672 33615393 200ee21 vmlinux.o

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: David S. Miller <davem@davemloft.net>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
CC: linux-bluetooth@vger.kernel.org
CC: linux-decnet-user@lists.sourceforge.net
CC: linux-wireless@vger.kernel.org
CC: linux-rdma@vger.kernel.org
CC: linux-sctp@vger.kernel.org
CC: linux-nfs@vger.kernel.org
CC: linux-x25@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

vfs: do bulk POLL* -> EPOLL* replacement

This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do. But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

net: delete /proc THIS_MODULE references

/proc has been ignoring struct file_operations::owner field for 10 years.
Specifically, it started with commit 786d7e1612f0b0adb6046f19b906609e4fe8b1ba
("Fix rmmod/read/write races in /proc entries"). Notice the chunk where
inode->i_fop is initialized with proxy struct file_operations for
regular files:

- if (de->proc_fops)
- inode->i_fop = de->proc_fops;
+ if (de->proc_fops) {
+ if (S_ISREG(inode->i_mode))
+ inode->i_fop = &proc_reg_file_ops;
+ else
+ inode->i_fop = de->proc_fops;
+ }

VFS stopped pinning module at this point.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: Add asynchronous callbacks for xfrm on layer 2.

This patch implements asynchronous crypto callbacks
and a backlog handler that can be used when IPsec
is done at layer 2 in the TX path. It also extends
the skb validate functions so that we can update
the driver transmit return codes based on async
crypto operation or to indicate that we queued the
packet in a backlog queue.

Joint work with: Aviv Heller <avivh@mellanox.com>

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

net/packet: fix a race in packet_bind() and packet_notifier()

syzbot reported crashes [1] and provided a C repro easing bug hunting.

When/if packet_do_bind() calls __unregister_prot_hook() and releases
po->bind_lock, another thread can run packet_notifier() and process an
NETDEV_UP event.

This calls register_prot_hook() and hooks again the socket right before
first thread is able to grab again po->bind_lock.

Fixes this issue by temporarily setting po->num to 0, as suggested by
David Miller.

[1]
dev_remove_pack: ffff8801bf16fa80 not found
------------[ cut here ]------------
kernel BUG at net/core/dev.c:7945! ( BUG_ON(!list_empty(&dev->ptype_all)); )
invalid opcode: 0000 [#1] SMP KASAN
Dumping ftrace buffer:
(ftrace buffer empty)
Modules linked in:
device syz0 entered promiscuous mode
CPU: 0 PID: 3161 Comm: syzkaller404108 Not tainted 4.14.0+ #190
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cc57a500 task.stack: ffff8801cc588000
RIP: 0010:netdev_run_todo+0x772/0xae0 net/core/dev.c:7945
RSP: 0018:ffff8801cc58f598 EFLAGS: 00010293
RAX: ffff8801cc57a500 RBX: dffffc0000000000 RCX: ffffffff841f75b2
RDX: 0000000000000000 RSI: 1ffff100398b1ede RDI: ffff8801bf1f8810
device syz0 entered promiscuous mode
RBP: ffff8801cc58f898 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801bf1f8cd8
R13: ffff8801cc58f870 R14: ffff8801bf1f8780 R15: ffff8801cc58f7f0
FS: 0000000001716880(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020b13000 CR3: 0000000005e25000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:106
tun_detach drivers/net/tun.c:670 [inline]
tun_chr_close+0x49/0x60 drivers/net/tun.c:2845
__fput+0x333/0x7f0 fs/file_table.c:210
____fput+0x15/0x20 fs/file_table.c:244
task_work_run+0x199/0x270 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0x9bb/0x1ae0 kernel/exit.c:865
do_group_exit+0x149/0x400 kernel/exit.c:968
SYSC_exit_group kernel/exit.c:979 [inline]
SyS_exit_group+0x1d/0x20 kernel/exit.c:977
entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x44ad19

Fixes: 30f7ea1c2b5f ("packet: race condition in packet_bind")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Francesco Ruggeri <fruggeri@aristanetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: fix crash in fanout_demux_rollover()

syzkaller found a race condition fanout_demux_rollover() while removing
a packet socket from a fanout group.

po->rollover is read and operated on during packet_rcv_fanout(), via
fanout_demux_rollover(), but the pointer is currently cleared before the
synchronization in packet_release(). It is safer to delay the cleanup
until after synchronize_net() has been called, ensuring all calls to
packet_rcv_fanout() for this socket have finished.

To further simplify synchronization around the rollover structure, set
po->rollover in fanout_add() only if there are no errors. This removes
the need for rcu in the struct and in the call to
packet_getsockopt(..., PACKET_ROLLOVER_STATS, ...).

Crashing stack trace:
fanout_demux_rollover+0xb6/0x4d0 net/packet/af_packet.c:1392
packet_rcv_fanout+0x649/0x7c8 net/packet/af_packet.c:1487
dev_queue_xmit_nit+0x835/0xc10 net/core/dev.c:1953
xmit_one net/core/dev.c:2975 [inline]
dev_hard_start_xmit+0x16b/0xac0 net/core/dev.c:2995
__dev_queue_xmit+0x17a4/0x2050 net/core/dev.c:3476
dev_queue_xmit+0x17/0x20 net/core/dev.c:3509
neigh_connected_output+0x489/0x720 net/core/neighbour.c:1379
neigh_output include/net/neighbour.h:482 [inline]
ip6_finish_output2+0xad1/0x22a0 net/ipv6/ip6_output.c:120
ip6_finish_output+0x2f9/0x920 net/ipv6/ip6_output.c:146
NF_HOOK_COND include/linux/netfilter.h:239 [inline]
ip6_output+0x1f4/0x850 net/ipv6/ip6_output.c:163
dst_output include/net/dst.h:459 [inline]
NF_HOOK.constprop.35+0xff/0x630 include/linux/netfilter.h:250
mld_sendpack+0x6a8/0xcc0 net/ipv6/mcast.c:1660
mld_send_initial_cr.part.24+0x103/0x150 net/ipv6/mcast.c:2072
mld_send_initial_cr net/ipv6/mcast.c:2056 [inline]
ipv6_mc_dad_complete+0x99/0x130 net/ipv6/mcast.c:2079
addrconf_dad_completed+0x595/0x970 net/ipv6/addrconf.c:4039
addrconf_dad_work+0xac9/0x1160 net/ipv6/addrconf.c:3971
process_one_work+0xbf0/0x1bc0 kernel/workqueue.c:2113
worker_thread+0x223/0x1990 kernel/workqueue.c:2247
kthread+0x35e/0x430 kernel/kthread.c:231
ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:432

Fixes: 0648ab70afe6 ("packet: rollover prepare: per-socket state")
Fixes: 509c7a1ecc860 ("packet: avoid panic in packet_getsockopt()")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Mike Maloney <maloney@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: annotate ->poll() instances

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

packet: exit_net cleanup check added

Be sure that packet.sklist initialized in net_init hook was return
to initial state.

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: af_packet: Convert timers to use timer_setup()

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Mike Maloney <maloney@google.com>
Cc: Jarno Rajahalme <jarno@ovn.org>
Cc: netdev@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: avoid panic in packet_getsockopt()

syzkaller got crashes in packet_getsockopt() processing
PACKET_ROLLOVER_STATS command while another thread was managing
to change po->rollover

Using RCU will fix this bug. We might later add proper RCU annotations
for sparse sake.

In v2: I replaced kfree(rollover) in fanout_add() to kfree_rcu()
variant, as spotted by John.

Fixes: a9b6391814d5 ("packet: rollover statistics")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: John Sperbeck <jsperbeck@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: only test po->has_vnet_hdr once in packet_snd

Packet socket option po->has_vnet_hdr can be updated concurrently with
other operations if no ring is attached.

Do not test the option twice in packet_snd, as the value may change in
between calls. A race on setsockopt disable may cause a packet > mtu
to be sent without having GSO options set.

Fixes: bfd5f4a3d605 ("packet: Add GSO/csum offload support.")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: in packet_do_bind, test fanout with bind_lock held

Once a socket has po->fanout set, it remains a member of the group
until it is destroyed. The prot_hook must be constant and identical
across sockets in the group.

If fanout_add races with packet_do_bind between the test of po->fanout
and taking the lock, the bind call may make type or dev inconsistent
with that of the fanout group.

Hold po->bind_lock when testing po->fanout to avoid this race.

I had to introduce artificial delay (local_bh_enable) to actually
observe the race.

Fixes: dc99f600698d ("packet: Add fanout support.")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: af_packet: use setup_timer() helper.

Use setup_timer function instead of initializing timer with the
function and data fields.

Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: hold bind lock when rebinding to fanout hook

Packet socket bind operations must hold the po->bind_lock. This keeps
po->running consistent with whether the socket is actually on a ptype
list to receive packets.

fanout_add unbinds a socket and its packet_rcv/tpacket_rcv call, then
binds the fanout object to receive through packet_rcv_fanout.

Make it hold the po->bind_lock when testing po->running and rebinding.
Else, it can race with other rebind operations, such as that in
packet_set_ring from packet_rcv to tpacket_rcv. Concurrent updates
can result in a socket being added to a fanout group twice, causing
use-after-free KASAN bug reports, among others.

Reported independently by both trinity and syzkaller.
Verified that the syzkaller reproducer passes after this patch.

Fixes: dc99f600698d ("packet: Add fanout support.")
Reported-by: nixioaming <nixiaoming@huawei.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: Don't write vnet header beyond end of buffer

... which may happen with certain values of tp_reserve and maclen.

Fixes: 58d19b19cd99 ("packet: vnet_hdr support for tpacket_rcv")
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: fix tp_reserve race in packet_set_ring

Updates to tp_reserve can race with reads of the field in
packet_set_ring. Avoid this by holding the socket lock during
updates in setsockopt PACKET_RESERVE.

This bug was discovered by syzkaller.

Fixes: 8913336a7e8d ("packet: add PACKET_RESERVE sockopt")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: fix use-after-free in prb_retire_rx_blk_timer_expired()

There are multiple reports showing we have a use-after-free in
the timer prb_retire_rx_blk_timer_expired(), where we use struct
tpacket_kbdq_core::pkbdq, a pg_vec, after it gets freed by
free_pg_vec().

The interesting part is it is not freed via packet_release() but
via packet_setsockopt(), which means we are not closing the socket.
Looking into the big and fat function packet_set_ring(), this could
happen if we satisfy the following conditions:

1. closing == 0, not on packet_release() path
2. req->tp_block_nr == 0, we don't allocate a new pg_vec
3. rx_ring->pg_vec is already set as V3, which means we already called
packet_set_ring() wtih req->tp_block_nr > 0 previously
4. req->tp_frame_nr == 0, pass sanity check
5. po->mapped == 0, never called mmap()

In this scenario we are clearing the old rx_ring->pg_vec, so we need
to free this pg_vec, but we don't stop the timer on this path because
of closing==0.

The timer has to be stopped as long as we need to free pg_vec, therefore
the check on closing!=0 is wrong, we should check pg_vec!=NULL instead.

Thanks to liujian for testing different fixes.

Reported-by: alexander.levin@verizon.com
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Reported-by: liujian (CE) <liujian56@huawei.com>
Tested-by: liujian (CE) <liujian56@huawei.com>
Cc: Ding Tianhong <dingtianhong@huawei.com>
Cc: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: remove unused PGV_FROM_VMALLOC definition.

This patch removes the definition of PGV_FROM_VMALLOC from af_packet.c.
The PGV_FROM_VMALLOC definition was already removed by
commit 441c793a5650 ("net: cleanup unused macros in net directory"),
and its usage was removed even before by commit c56b4d90123b
("af_packet: remove pgv.flags"); but it was added back by mistake later on,
in commit f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation").

Signed-off-by: Rami Rosen <rami.rosen@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: Fix Tx queue selection for AF_PACKET

When PACKET_QDISC_BYPASS is not used, Tx queue selection will be done
before the packet is enqueued, taking into account any mappings set by
a queuing discipline such as mqprio without hardware offloading. This
selection may be affected by a previously saved queue_mapping, either on
the Rx path, or done before the packet reaches the device, as it's
currently the case for AF_PACKET.

In order for queue selection to work as expected when using traffic
control, there can't be another selection done before that point is
reached, so move the call to packet_pick_tx_queue to
packet_direct_xmit, leaving the default xmit path as it was before
PACKET_QDISC_BYPASS was introduced.

A forward declaration of packet_pick_tx_queue() is introduced to avoid
the need to reorder the functions within the file.

Fixes: d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option")
Signed-off-by: Iván Briano <ivan.briano@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: convert packet_fanout.sk_ref from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: convert sock.sk_refcnt from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: convert sock.sk_wmem_alloc from atomic_t to refcount_t

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: remove unneeded declaraion of tpacket_snd().

This patch removes unneeded forward declaration of tpacket_snd()
in net/packet/af_packet.c.

Signed-off-by: Rami Rosen <rami.rosen@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: remove unused parameter in prb_curr_blk_in_use().

This patch removes unused parameter from prb_curr_blk_in_use() method
in net/packet/af_packet.c.

Signed-off-by: Rami Rosen <rami.rosen@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: fix missing net_device reference release

When using a TX ring buffer, if an error occurs processing a control
message (e.g. invalid message), the net_device reference is not
released.

Fixes c14ac9451c348 ("sock: enable timestamping using control messages")
Signed-off-by: Douglas Caetano dos Santos <douglascs@taghos.com.br>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: check length in getsockopt() called with PACKET_HDRLEN

In the case getsockopt() is called with PACKET_HDRLEN and optlen < 4
|val| remains uninitialized and the syscall may behave differently
depending on its value, and even copy garbage to userspace on certain
architectures. To fix this we now return -EINVAL if optlen is too small.

This bug has been detected with KMSAN.

Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: add PACKET_FANOUT_FLAG_UNIQUEID to assign new fanout group id.

Fanout uses a per net global namespace. A process that intends to create
a new fanout group can accidentally join an existing group. It is not
possible to detect this.

Add socket option PACKET_FANOUT_FLAG_UNIQUEID. When specified the
supplied fanout group id must be set to 0, and the kernel chooses an id
that is not already in use. This is an ephemeral flag so that
other sockets can be added to this group using setsockopt, but NOT
specifying this flag. The current getsockopt(..., PACKET_FANOUT, ...)
can be used to retrieve the new group id.

We assume that there are not a lot of fanout groups and that this is not
a high frequency call.

The method assigns ids starting at zero and increases until it finds an
unused id. It keeps track of the last assigned id, and uses it as a
starting point to find new ids.

Signed-off-by: Mike Maloney <maloney@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/packet: fix overflow in check for tp_reserve

When calculating po->tp_hdrlen + po->tp_reserve the result can overflow.

Fix by checking that tp_reserve <= INT_MAX on assign.

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

net/packet: fix overflow in check for tp_frame_nr

When calculating rb->frames_per_block * req->tp_block_nr the result
can overflow.

Add a check that tp_block_size * tp_block_nr <= UINT_MAX.

Since frames_per_block <= tp_block_size, the expression would
never overflow.

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

net/packet: fix overflow in check for priv area size

Subtracting tp_sizeof_priv from tp_block_size and casting to int
to check whether one is less then the other doesn't always work
(both of them are unsigned ints).

Compare them as is instead.

Also cast tp_sizeof_priv to u64 before using BLK_PLUS_PRIV, as
it can overflow inside BLK_PLUS_PRIV otherwise.

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

net: don't call strlen() on the user buffer in packet_bind_spkt()

KMSAN (KernelMemorySanitizer, a new error detection tool) reports use of
uninitialized memory in packet_bind_spkt():
Acked-by: Eric Dumazet <edumazet@google.com>

==================================================================
BUG: KMSAN: use of unitialized memory
CPU: 0 PID: 1074 Comm: packet Not tainted 4.8.0-rc6+ #1891
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
01/01/2011
0000000000000000 ffff88006b6dfc08 ffffffff82559ae8 ffff88006b6dfb48
ffffffff818a7c91 ffffffff85b9c870 0000000000000092 ffffffff85b9c550
0000000000000000 0000000000000092 00000000ec400911 0000000000000002
Call Trace:
[< inline >] __dump_stack lib/dump_stack.c:15
[<ffffffff82559ae8>] dump_stack+0x238/0x290 lib/dump_stack.c:51
[<ffffffff818a6626>] kmsan_report+0x276/0x2e0 mm/kmsan/kmsan.c:1003
[<ffffffff818a783b>] __msan_warning+0x5b/0xb0
mm/kmsan/kmsan_instr.c:424
[< inline >] strlen lib/string.c:484
[<ffffffff8259b58d>] strlcpy+0x9d/0x200 lib/string.c:144
[<ffffffff84b2eca4>] packet_bind_spkt+0x144/0x230
net/packet/af_packet.c:3132
[<ffffffff84242e4d>] SYSC_bind+0x40d/0x5f0 net/socket.c:1370
[<ffffffff84242a22>] SyS_bind+0x82/0xa0 net/socket.c:1356
[<ffffffff8515991b>] entry_SYSCALL_64_fastpath+0x13/0x8f
arch/x86/entry/entry_64.o:?
chained origin: 00000000eba00911
[<ffffffff810bb787>] save_stack_trace+0x27/0x50
arch/x86/kernel/stacktrace.c:67
[< inline >] kmsan_save_stack_with_flags mm/kmsan/kmsan.c:322
[< inline >] kmsan_save_stack mm/kmsan/kmsan.c:334
[<ffffffff818a59f8>] kmsan_internal_chain_origin+0x118/0x1e0
mm/kmsan/kmsan.c:527
[<ffffffff818a7773>] __msan_set_alloca_origin4+0xc3/0x130
mm/kmsan/kmsan_instr.c:380
[<ffffffff84242b69>] SYSC_bind+0x129/0x5f0 net/socket.c:1356
[<ffffffff84242a22>] SyS_bind+0x82/0xa0 net/socket.c:1356
[<ffffffff8515991b>] entry_SYSCALL_64_fastpath+0x13/0x8f
arch/x86/entry/entry_64.o:?
origin description: ----address@SYSC_bind (origin=00000000eb400911)
==================================================================
(the line numbers are relative to 4.8-rc6, but the bug persists
upstream)

, when I run the following program as root:

=====================================
#include <string.h>
#include <sys/socket.h>
#include <netpacket/packet.h>
#include <net/ethernet.h>

int main() {
struct sockaddr addr;
memset(&addr, 0xff, sizeof(addr));
addr.sa_family = AF_PACKET;
int fd = socket(PF_PACKET, SOCK_PACKET, htons(ETH_P_ALL));
bind(fd, &addr, sizeof(addr));
return 0;
}
=====================================

This happens because addr.sa_data copied from the userspace is not
zero-terminated, and copying it with strlcpy() in packet_bind_spkt()
results in calling strlen() on the kernel copy of that non-terminated
buffer.

Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: Do not call fanout_release from atomic contexts

Commit 6664498280cf ("packet: call fanout_release, while UNREGISTERING a
netdev"), unfortunately, introduced the following issues.

1. calling mutex_lock(&fanout_mutex) (fanout_release()) from inside
rcu_read-side critical section. rcu_read_lock disables preemption, most often,
which prohibits calling sleeping functions.

[ ] include/linux/rcupdate.h:560 Illegal context switch in RCU read-side critical section!
[ ]
[ ] rcu_scheduler_active = 1, debug_locks = 0
[ ] 4 locks held by ovs-vswitchd/1969:
[ ] #0: (cb_lock){++++++}, at: [<ffffffff8158a6c9>] genl_rcv+0x19/0x40
[ ] #1: (ovs_mutex){+.+.+.}, at: [<ffffffffa04878ca>] ovs_vport_cmd_del+0x4a/0x100 [openvswitch]
[ ] #2: (rtnl_mutex){+.+.+.}, at: [<ffffffff81564157>] rtnl_lock+0x17/0x20
[ ] #3: (rcu_read_lock){......}, at: [<ffffffff81614165>] packet_notifier+0x5/0x3f0
[ ]
[ ] Call Trace:
[ ] [<ffffffff813770c1>] dump_stack+0x85/0xc4
[ ] [<ffffffff810c9077>] lockdep_rcu_suspicious+0x107/0x110
[ ] [<ffffffff810a2da7>] ___might_sleep+0x57/0x210
[ ] [<ffffffff810a2fd0>] __might_sleep+0x70/0x90
[ ] [<ffffffff8162e80c>] mutex_lock_nested+0x3c/0x3a0
[ ] [<ffffffff810de93f>] ? vprintk_default+0x1f/0x30
[ ] [<ffffffff81186e88>] ? printk+0x4d/0x4f
[ ] [<ffffffff816106dd>] fanout_release+0x1d/0xe0
[ ] [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0

2. calling mutex_lock(&fanout_mutex) inside spin_lock(&po->bind_lock).
"sleeping function called from invalid context"

[ ] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[ ] in_atomic(): 1, irqs_disabled(): 0, pid: 1969, name: ovs-vswitchd
[ ] INFO: lockdep is turned off.
[ ] Call Trace:
[ ] [<ffffffff813770c1>] dump_stack+0x85/0xc4
[ ] [<ffffffff810a2f52>] ___might_sleep+0x202/0x210
[ ] [<ffffffff810a2fd0>] __might_sleep+0x70/0x90
[ ] [<ffffffff8162e80c>] mutex_lock_nested+0x3c/0x3a0
[ ] [<ffffffff816106dd>] fanout_release+0x1d/0xe0
[ ] [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0

3. calling dev_remove_pack(&fanout->prot_hook), from inside
spin_lock(&po->bind_lock) or rcu_read-side critical-section. dev_remove_pack()
-> synchronize_net(), which might sleep.

[ ] BUG: scheduling while atomic: ovs-vswitchd/1969/0x00000002
[ ] INFO: lockdep is turned off.
[ ] Call Trace:
[ ] [<ffffffff813770c1>] dump_stack+0x85/0xc4
[ ] [<ffffffff81186274>] __schedule_bug+0x64/0x73
[ ] [<ffffffff8162b8cb>] __schedule+0x6b/0xd10
[ ] [<ffffffff8162c5db>] schedule+0x6b/0x80
[ ] [<ffffffff81630b1d>] schedule_timeout+0x38d/0x410
[ ] [<ffffffff810ea3fd>] synchronize_sched_expedited+0x53d/0x810
[ ] [<ffffffff810ea6de>] synchronize_rcu_expedited+0xe/0x10
[ ] [<ffffffff8154eab5>] synchronize_net+0x35/0x50
[ ] [<ffffffff8154eae3>] dev_remove_pack+0x13/0x20
[ ] [<ffffffff8161077e>] fanout_release+0xbe/0xe0
[ ] [<ffffffff81614459>] packet_notifier+0x2f9/0x3f0

4. fanout_release() races with calls from different CPU.

To fix the above problems, remove the call to fanout_release() under
rcu_read_lock(). Instead, call __dev_remove_pack(&fanout->prot_hook) and
netdev_run_todo will be happy that &dev->ptype_specific list is empty. In order
to achieve this, I moved dev_{add,remove}_pack() out of fanout_{add,release} to
__fanout_{link,unlink}. So, call to {,__}unregister_prot_hook() will make sure
fanout->prot_hook is removed as well.

Fixes: 6664498280cf ("packet: call fanout_release, while UNREGISTERING a netdev")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Anoob Soman <anoob.soman@citrix.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: fix races in fanout_add()

Multiple threads can call fanout_add() at the same time.

We need to grab fanout_mutex earlier to avoid races that could
lead to one thread freeing po->rollover that was set by another thread.

Do the same in fanout_release(), for peace of mind, and to help us
finding lockdep issues earlier.

Fixes: dc99f600698d ("packet: Add fanout support.")
Fixes: 0648ab70afe6 ("packet: rollover prepare: per-socket state")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: round up linear to header len

Link layer protocols may unconditionally pull headers, as Ethernet
does in eth_type_trans. Ensure that the entire link layer header
always lies in the skb linear segment. tpacket_snd has such a check.
Extend this to packet_snd.

Variable length link layer headers complicate the computation
somewhat. Here skb->len may be smaller than dev->hard_header_len.

Round up the linear length to be at least as long as the smallest of
the two.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

virtio-net: restore VIRTIO_HDR_F_DATA_VALID on receiving

Commit 501db511397f ("virtio: don't set VIRTIO_NET_HDR_F_DATA_VALID on
xmit") in fact disables VIRTIO_HDR_F_DATA_VALID on receiving path too,
fixing this by adding a hint (has_data_valid) and set it only on the
receiving path.

Cc: Rolf Neugebauer <rolf.neugebauer@docker.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Rolf Neugebauer <rolf.neugebauer@docker.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: fix panic in __packet_set_timestamp on tpacket_v3 in tx mode

When TX timestamping is in use with TPACKET_V3's TX ring, then we'll
hit the BUG() in __packet_set_timestamp() when ring buffer slot is
returned to user space via tpacket_destruct_skb(). This is due to v3
being assumed as unreachable here, but since 7f953ab2ba46 ("af_packet:
TX_RING support for TPACKET_V3") it's not anymore. Fix it by filling
the timestamp back into the ring slot.

Fixes: 7f953ab2ba46 ("af_packet: TX_RING support for TPACKET_V3")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: TX_RING support for TPACKET_V3

Although TPACKET_V3 Rx has some benefits over TPACKET_V2 Rx, *_v3
does not currently have TX_RING support. As a result an application
that wants the best perf for Tx and Rx (e.g. to handle request/response
transacations) ends up needing 2 sockets, one with *_v2 for Tx and
another with *_v3 for Rx.

This patch enables TPACKET_V2 compatible Tx features in TPACKET_V3
so that an application can use a single descriptor to get the benefits
of _v3 RX_RING and _v2 TX_RING. An application may do a block-send by
first filling up multiple frames in the Tx ring and then triggering a
transmit. This patch only support fixed size Tx frames for TPACKET_V3,
and requires that tp_next_offset must be zero.

Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Replace <asm/uaccess.h> with <linux/uaccess.h> globally

This was entirely automated, using the script by Al:

PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
$(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[iov_iter] new primitives - copy_from_iter_full() and friends

copy_from_iter_full(), copy_from_iter_full_nocache() and
csum_and_copy_from_iter_full() - counterparts of copy_from_iter()
et.al., advancing iterator only in case of successful full copy
and returning whether it had been successful or not.

Convert some obvious users. *NOTE* - do not blindly assume that
something is a good candidate for those unless you are sure that
not advancing iov_iter in failure case is the right thing in
this case. Anything that does short read/short write kind of
stuff (or is in a loop, etc.) is unlikely to be a good one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

packet: fix race condition in packet_set_ring

When packet_set_ring creates a ring buffer it will initialize a
struct timer_list if the packet version is TPACKET_V3. This value
can then be raced by a different thread calling setsockopt to
set the version to TPACKET_V1 before packet_set_ring has finished.

This leads to a use-after-free on a function pointer in the
struct timer_list when the socket is closed as the previously
initialized timer will not be deleted.

The bug is fixed by taking lock_sock(sk) in packet_setsockopt when
changing the packet version while also taking the lock at the start
of packet_set_ring.

Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.")
Signed-off-by: Philip Pettersson <philip.pettersson@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: Use virtio_net_hdr_from_skb() directly.

Remove static function __packet_rcv_vnet(), which only called
virtio_net_hdr_from_skb() and BUG()ged out if an error code was
returned. Instead, call virtio_net_hdr_from_skb() from the former
call sites of __packet_rcv_vnet() and actually use the error handling
code that is already there.

Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: Use virtio_net_hdr_to_skb().

Use the common virtio_net_hdr_to_skb() instead of open coding it.
Other call sites were changed by commit fd2a0437dc, but this one was
missed, maybe because it is split in two parts of the source code.

Interim comparisons of 'vnet_hdr->gso_type' still work as both the
vnet_hdr and skb notion of gso_type is zero when there is no gso.

Fixes: fd2a0437dc ("virtio_net: introduce virtio_net_hdr_{from,to}_skb")
Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

virtio_net: Do not clear memory for struct virtio_net_hdr twice.

virtio_net_hdr_from_skb() clears the memory for the header, so there
is no point for the callers to do the same.

Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: on direct_xmit, limit tso and csum to supported devices

When transmitting on a packet socket with PACKET_VNET_HDR and
PACKET_QDISC_BYPASS, validate device support for features requested
in vnet_hdr.

Drop TSO packets sent to devices that do not support TSO or have the
feature disabled. Note that the latter currently do process those
packets correctly, regardless of not advertising the feature.

Because of SKB_GSO_DODGY, it is not sufficient to test device features
with netif_needs_gso. Full validate_xmit_skb is needed.

Switch to software checksum for non-TSO packets that request checksum
offload if that device feature is unsupported or disabled. Note that
similar to the TSO case, device drivers may perform checksum offload
correctly even when not advertising it.

When switching to software checksum, packets hit skb_checksum_help,
which has two BUG_ON checksum not in linear segment. Packet sockets
always allocate at least up to csum_start + csum_off + 2 as linear.

Tested by running github.com/wdebruij/kerneltools/psock_txring_vnet.c

ethtool -K eth0 tso off tx on
psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v
psock_txring_vnet -d $dst -s $src -i eth0 -l 2000 -n 1 -q -v -N

ethtool -K eth0 tx off
psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G
psock_txring_vnet -d $dst -s $src -i eth0 -l 1000 -n 1 -q -v -G -N

v2:
- add EXPORT_SYMBOL_GPL(validate_xmit_skb_list)

Fixes: d346a3fae3ff ("packet: introduce PACKET_QDISC_BYPASS socket option")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: call fanout_release, while UNREGISTERING a netdev

If a socket has FANOUT sockopt set, a new proto_hook is registered
as part of fanout_add(). When processing a NETDEV_UNREGISTER event in
af_packet, __fanout_unlink is called for all sockets, but prot_hook which was
registered as part of fanout_add is not removed. Call fanout_release, on a
NETDEV_UNREGISTER, which removes prot_hook and removes fanout from the
fanout_list.

This fixes BUG_ON(!list_empty(&dev->ptype_specific)) in netdev_run_todo()

Signed-off-by: Anoob Soman <anoob.soman@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: propagate sock_cmsg_send() error

sock_cmsg_send() can return different error codes and not only
-EINVAL, and we should properly propagate them.

Fixes: c14ac9451c34 ("sock: enable timestamping using control messages")
Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: fix second argument of sock_tx_timestamp()

This patch fixes an issue that a syscall (e.g. sendto syscall) cannot
work correctly. Since the sendto syscall doesn't have msg_control buffer,
the sock_tx_timestamp() in packet_snd() cannot work correctly because
the socks.tsflags is set to 0.
So, this patch sets the socks.tsflags to sk->sk_tsflags as default.

Fixes: c14ac9451c34 ("sock: enable timestamping using control messages")
Reported-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
Reported-by: Keita Kobayashi <keita.kobayashi.ym@renesas.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: Use symmetric hash for PACKET_FANOUT_HASH.

People who use PACKET_FANOUT_HASH want a symmetric hash, meaning that
they want packets going in both directions on a flow to hash to the
same bucket.

The core kernel SKB hash became non-symmetric when the ipv6 flow label
and other entities were incorporated into the standard flow hash order
to increase entropy.

But there are no users of PACKET_FANOUT_HASH who want an assymetric
hash, they all want a symmetric one.

Therefore, use the flow dissector to compute a flat symmetric hash
over only the protocol, addresses and ports. This hash does not get
installed into and override the normal skb hash, so this change has
no effect whatsoever on the rest of the stack.

Reported-by: Eric Leblond <eric@regit.org>
Tested-by: Eric Leblond <eric@regit.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

bpf: refactor bpf_prog_get and type check into helper

Since bpf_prog_get() and program type check is used in a couple of places,
refactor this into a small helper function that we can make use of. Since
the non RO prog->aux part is not used in performance critical paths and a
program destruction via RCU is rather very unlikley when doing the put, we
shouldn't have an issue just doing the bpf_prog_get() + prog->type != type
check, but actually not taking the ref at all (due to being in fdget() /
fdput() section of the bpf fd) is even cleaner and makes the diff smaller
as well, so just go for that. Callsites are changed to make use of the new
helper where possible.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: use common code for virtio_net_hdr and skb GSO conversion

Replace open coded conversion between virtio_net_hdr to skb GSO info with
virtio_net_hdr_from_skb

Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: compat support for sock_fprog

Socket option PACKET_FANOUT_DATA takes a struct sock_fprog as argument
if PACKET_FANOUT has mode PACKET_FANOUT_CBPF. This structure contains
a pointer into user memory. If userland is 32-bit and kernel is 64-bit
the two disagree about the layout of struct sock_fprog.

Add compat setsockopt support to convert a 32-bit compat_sock_fprog to
a 64-bit sock_fprog. This is analogous to compat_sock_fprog support for
SO_REUSEPORT added in commit 1957598840f4 ("soreuseport: add compat
case for setsockopt SO_ATTACH_REUSEPORT_CBPF").

Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: uses kfree_skb() for errors.

consume_skb() isn't for error cases that kfree_skb() is more proper
one. At this patch, it fixed tpacket_rcv() and packet_rcv() to be
consistent for error or non-error cases letting perf trace its event
properly.

Signed-off-by: Weongyo Jeong <weongyo.linux@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: fix heap info leak in PACKET_DIAG_MCLIST sock_diag interface

Because we miss to wipe the remainder of i->addr[] in packet_mc_add(),
pdiag_put_mclist() leaks uninitialized heap bytes via the
PACKET_DIAG_MCLIST netlink attribute.

Fix this by explicitly memset(0)ing the remaining bytes in i->addr[].

Fixes: eea68e2f1a00 ("packet: Report socket mclist info via diag module")
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

af_packet: tone down the Tx-ring unsupported spew.

Trinity and other fuzzers can hit this WARN on far too easily,
resulting in a tainted kernel that hinders automated fuzzing.

Replace it with a rate-limited printk.

Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

sock: enable timestamping using control messages

Currently, SOL_TIMESTAMPING can only be enabled using setsockopt.
This is very costly when users want to sample writes to gather
tx timestamps.

Add support for enabling SO_TIMESTAMPING via control messages by
using tsflags added in `struct sockcm_cookie` (added in the previous
patches in this series) to set the tx_flags of the last skb created in
a sendmsg. With this patch, the timestamp recording bits in tx_flags
of the skbuff is overridden if SO_TIMESTAMPING is passed in a cmsg.

Please note that this is only effective for overriding the recording
timestamps flags. Users should enable timestamp reporting (e.g.,
SOF_TIMESTAMPING_SOFTWARE | SOF_TIMESTAMPING_OPT_ID) using
socket options and then should ask for SOF_TIMESTAMPING_TX_*
using control messages per sendmsg to sample timestamps for each
write.

Signed-off-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: validate variable length ll headers

Replace link layer header validation check ll_header_truncate with
more generic dev_validate_header.

Validation based on hard_header_len incorrectly drops valid packets
in variable length protocols, such as AX25. dev_validate_header
calls header_ops.validate for such protocols to ensure correctness
below hard_header_len.

See also http://comments.gmane.org/gmane.linux.network/401064

Fixes 9c7077622dd9 ("packet: make packet_snd fail on len smaller than l2 header")
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: core: use __ethtool_get_ksettings

Signed-off-by: David Decotigny <decot@googlers.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: tpacket_snd gso and checksum offload

Support socket option PACKET_VNET_HDR together with PACKET_TX_RING.

When enabled, a struct virtio_net_hdr is expected to precede the data
in the ring. The vnet option must be set before the ring is created.

The implementation reuses the existing skb_copy_bits code that is used
when dev->hard_header_len is non-zero. Move this ll_header check to
before the skb alloc and combine it with a test for vnet_hdr->hdr_len.
Allocate and copy the max of the two.

Verified with test program at
github.com/wdebruij/kerneltools/blob/master/tests/psock_txring_vnet.c

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: parse tpacket header before skb alloc

GSO packet headers must be stored in the linear skb segment.
Move tpacket header parsing before sock_alloc_send_skb. The GSO
follow-on patch will later increase the skb linear argument to
sock_alloc_send_skb if needed for large packets.

The header parsing code does not require an allocated skb, so is
safe to move. Later pass to tpacket_fill_skb the computed data
start and length.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: vnet_hdr support for tpacket_rcv

Support socket option PACKET_VNET_HDR together with PACKET_RX_RING.
When enabled, a struct virtio_net_hdr will precede the data in the
packet ring slots.

Verified with test program at
github.com/wdebruij/kerneltools/blob/master/tests/psock_rxring_vnet.c

pkt: 1454269209.798420 len=5066
vnet: gso_type=tcpv4 gso_size=1448 hlen=66 ecn=off
csum: start=34 off=16
eth: proto=0x800
ip: src=<masked> dst=<masked> proto=6 len=5052

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: move vnet_hdr code to helper functions

packet_snd and packet_rcv support virtio net headers for GSO.
Move this logic into helper functions to be able to reuse it in
tpacket_snd and tpacket_rcv.

This is a straighforward code move with one exception. Instead of
creating and passing a separate gso_type variable, reuse
vnet_hdr.gso_type after conversion from virtio to kernel gso type.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: Allow packets with only a header (but no payload)

Commit 9c7077622dd91 ("packet: make packet_snd fail on len smaller
than l2 header") added validation for the packet size in packet_snd.
This change enforces that every packet needs a header (with at least
hard_header_len bytes) plus a payload with at least one byte. Before
this change the payload was optional.

This fixes PPPoE connections which do not have a "Service" or
"Host-Uniq" configured (which is violating the spec, but is still
widely used in real-world setups). Those are currently failing with the
following message: "pppd: packet size is too short (24 <= 24)"

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: Use PAGE_ALIGNED macro

Use PAGE_ALIGNED(...) instead of open-coding it.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: Don't check frames_per_block against negative values

rb->frames_per_block is an unsigned int, thus can never be negative.

Also fix spacing in the calculation of frames_per_block.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

packet: fix tpacket_snd max frame len

Since it's introduction in commit 69e3c75f4d54 ("net: TX_RING and
packet mmap"), TX_RING could be used from SOCK_DGRAM and SOCK_RAW
side. When used with SOCK_DGRAM only, the size_max > dev->mtu +
reserve check should have reserve as 0, but currently, this is
unconditionally set (in it's original form as dev->hard_header_len).

I think this is not correct since tpacket_fill_skb() would then
take dev->mtu and dev->hard_header_len into account for SOCK_DGRAM,
the extra VLAN_HLEN could be possible in both cases. Presumably, the
reserve code was copied from packet_snd(), but later on missed the
check. Make it similar as we have it in packet_snd().

Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>