net/sched: Add module alias for sch_fq_pie

The commit 2c15a5aee2f3 ("net/sched: Load modules via their alias")
starts loading modules via aliases and not canonical names. The new
aliases were added in commit 241a94abcf46 ("net/sched: Add module
aliases for cls_,sch_,act_ modules") via a Coccinele script.

sch_fq_pie.c is missing module.h header and thus Coccinele did not patch
it. Add the include and module alias manually, so that autoloading works
for sch_fq_pie too.

(Note: commit message in commit 241a94abcf46 ("net/sched: Add module
aliases for cls_,sch_,act_ modules") was mangled due to '#'
misinterpretation. The predicate haskernel is:

| @ haskernel @
| @@
|
| #include <linux/module.h>
|
.)

Fixes: 241a94abcf46 ("net/sched: Add module aliases for cls_,sch_,act_ modules")
Signed-off-by: Michal Koutný <mkoutny@suse.com>
Link: https://lore.kernel.org/r/20240315160210.8379-1-mkoutny@suse.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

netlink: make range pointers in policies const

struct nla_policy is usually constant itself, but unless
we make the ranges inside constant we won't be able to
make range structs const. The ranges are not modified
by the core.

Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20231025162204.132528-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/sched: fq_pie: avoid stalls in fq_pie_timer()

When setting a high number of flows (limit being 65536),
fq_pie_timer() is currently using too much time as syzbot reported.

Add logic to yield the cpu every 2048 flows (less than 150 usec
on debug kernels).
It should also help by not blocking qdisc fast paths for too long.
Worst case (65536 flows) would need 31 jiffies for a complete scan.

Relevant extract from syzbot report:

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-.... } 2663 jiffies s: 873 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5177 Comm: syz-executor273 Not tainted 6.5.0-syzkaller-00453-g727dbda16b83 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:write_comp_data+0x21/0x90 kernel/kcov.c:236
Code: 2e 0f 1f 84 00 00 00 00 00 65 8b 05 01 b2 7d 7e 49 89 f1 89 c6 49 89 d2 81 e6 00 01 00 00 49 89 f8 65 48 8b 14 25 80 b9 03 00 <a9> 00 01 ff 00 74 0e 85 f6 74 59 8b 82 04 16 00 00 85 c0 74 4f 8b
RSP: 0018:ffffc90000007bb8 EFLAGS: 00000206
RAX: 0000000000000101 RBX: ffffc9000dc0d140 RCX: ffffffff885893b0
RDX: ffff88807c075940 RSI: 0000000000000100 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffc9000dc0d178
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000555555d54380(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6b442f6130 CR3: 000000006fe1c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<IRQ>
pie_calculate_probability+0x480/0x850 net/sched/sch_pie.c:415
fq_pie_timer+0x1da/0x4f0 net/sched/sch_fq_pie.c:387
call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700

Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
Link: https://lore.kernel.org/lkml/00000000000017ad3f06040bf394@google.com/
Reported-by: syzbot+e46fbd5289363464bc13@syzkaller.appspotmail.com
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20230829123541.3745013-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: sched: add rcu annotations around qdisc->qdisc_sleeping

syzbot reported a race around qdisc->qdisc_sleeping [1]

It is time we add proper annotations to reads and writes to/from
qdisc->qdisc_sleeping.

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

read to 0xffff8881286fc618 of 8 bytes by task 6928 on cpu 1:
qdisc_lookup_rcu+0x192/0x2c0 net/sched/sch_api.c:331
__tcf_qdisc_find+0x74/0x3c0 net/sched/cls_api.c:1174
tc_get_tfilter+0x18f/0x990 net/sched/cls_api.c:2547
rtnetlink_rcv_msg+0x7af/0x8c0 net/core/rtnetlink.c:6386
netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2546
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6413
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x375/0x4c0 net/socket.c:2503
___sys_sendmsg net/socket.c:2557 [inline]
__sys_sendmsg+0x1e3/0x270 net/socket.c:2586
__do_sys_sendmsg net/socket.c:2595 [inline]
__se_sys_sendmsg net/socket.c:2593 [inline]
__x64_sys_sendmsg+0x46/0x50 net/socket.c:2593
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

write to 0xffff8881286fc618 of 8 bytes by task 6912 on cpu 0:
dev_graft_qdisc+0x4f/0x80 net/sched/sch_generic.c:1115
qdisc_graft+0x7d0/0xb60 net/sched/sch_api.c:1103
tc_modify_qdisc+0x712/0xf10 net/sched/sch_api.c:1693
rtnetlink_rcv_msg+0x807/0x8c0 net/core/rtnetlink.c:6395
netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2546
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6413
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x375/0x4c0 net/socket.c:2503
___sys_sendmsg net/socket.c:2557 [inline]
__sys_sendmsg+0x1e3/0x270 net/socket.c:2586
__do_sys_sendmsg net/socket.c:2595 [inline]
__se_sys_sendmsg net/socket.c:2593 [inline]
__x64_sys_sendmsg+0x46/0x50 net/socket.c:2593
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 6912 Comm: syz-executor.5 Not tainted 6.4.0-rc3-syzkaller-00190-g0d85b27b0cc6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/16/2023

Fixes: 3a7d0d07a386 ("net: sched: extend Qdisc with rcu")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Vlad Buslov <vladbu@nvidia.com>
Acked-by: Jamal Hadi Salim<jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched: fq_pie: ensure reasonable TCA_FQ_PIE_QUANTUM values

We got multiple syzbot reports, all duplicates of the following [1]

syzbot managed to install fq_pie with a zero TCA_FQ_PIE_QUANTUM,
thus triggering infinite loops.

Use limits similar to sch_fq, with commits
3725a269815b ("pkt_sched: fq: avoid hang when quantum 0") and
d9e15a273306 ("pkt_sched: fq: do not accept silly TCA_FQ_QUANTUM")

[1]
watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [swapper/0:0]
Modules linked in:
irq event stamp: 172817
hardirqs last enabled at (172816): [<ffff80001242fde4>] __el1_irq arch/arm64/kernel/entry-common.c:476 [inline]
hardirqs last enabled at (172816): [<ffff80001242fde4>] el1_interrupt+0x58/0x68 arch/arm64/kernel/entry-common.c:486
hardirqs last disabled at (172817): [<ffff80001242fdb0>] __el1_irq arch/arm64/kernel/entry-common.c:468 [inline]
hardirqs last disabled at (172817): [<ffff80001242fdb0>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:486
softirqs last enabled at (167634): [<ffff800008020c1c>] softirq_handle_end kernel/softirq.c:414 [inline]
softirqs last enabled at (167634): [<ffff800008020c1c>] __do_softirq+0xac0/0xd54 kernel/softirq.c:600
softirqs last disabled at (167701): [<ffff80000802a660>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-rc3-syzkaller-geb0f1697d729 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : fq_pie_qdisc_dequeue+0x10c/0x8ac net/sched/sch_fq_pie.c:246
lr : fq_pie_qdisc_dequeue+0xe4/0x8ac net/sched/sch_fq_pie.c:240
sp : ffff800008007210
x29: ffff800008007280 x28: ffff0000c86f7890 x27: ffff0000cb20c2e8
x26: ffff0000cb20c2f0 x25: dfff800000000000 x24: ffff0000cb20c2e0
x23: ffff0000c86f7880 x22: 0000000000000040 x21: 1fffe000190def10
x20: ffff0000cb20c2e0 x19: ffff0000cb20c2e0 x18: ffff800008006e60
x17: 0000000000000000 x16: ffff80000850af6c x15: 0000000000000302
x14: 0000000000000100 x13: 0000000000000000 x12: 0000000000000001
x11: 0000000000000302 x10: 0000000000000100 x9 : 0000000000000000
x8 : 0000000000000000 x7 : ffff80000841c468 x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000001 x3 : 0000000000000000
x2 : ffff0000cb20c2e0 x1 : ffff0000cb20c2e0 x0 : 0000000000000001
Call trace:
fq_pie_qdisc_dequeue+0x10c/0x8ac net/sched/sch_fq_pie.c:246
dequeue_skb net/sched/sch_generic.c:292 [inline]
qdisc_restart net/sched/sch_generic.c:397 [inline]
__qdisc_run+0x1fc/0x231c net/sched/sch_generic.c:415
__dev_xmit_skb net/core/dev.c:3868 [inline]
__dev_queue_xmit+0xc80/0x3318 net/core/dev.c:4210
dev_queue_xmit include/linux/netdevice.h:3085 [inline]
neigh_connected_output+0x2f8/0x38c net/core/neighbour.c:1581
neigh_output include/net/neighbour.h:544 [inline]
ip6_finish_output2+0xd60/0x1a1c net/ipv6/ip6_output.c:134
__ip6_finish_output net/ipv6/ip6_output.c:195 [inline]
ip6_finish_output+0x538/0x8c8 net/ipv6/ip6_output.c:206
NF_HOOK_COND include/linux/netfilter.h:292 [inline]
ip6_output+0x270/0x594 net/ipv6/ip6_output.c:227
dst_output include/net/dst.h:458 [inline]
NF_HOOK include/linux/netfilter.h:303 [inline]
ndisc_send_skb+0xc30/0x1790 net/ipv6/ndisc.c:508
ndisc_send_rs+0x47c/0x5d4 net/ipv6/ndisc.c:718
addrconf_rs_timer+0x300/0x58c net/ipv6/addrconf.c:3936
call_timer_fn+0x19c/0x8cc kernel/time/timer.c:1700
expire_timers kernel/time/timer.c:1751 [inline]
__run_timers+0x55c/0x734 kernel/time/timer.c:2022
run_timer_softirq+0x7c/0x114 kernel/time/timer.c:2035
__do_softirq+0x2d0/0xd54 kernel/softirq.c:571
____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80
call_on_irq_stack+0x24/0x4c arch/arm64/kernel/entry.S:882
do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:85
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0x28c/0x534 kernel/softirq.c:650
irq_exit_rcu+0x14/0x84 kernel/softirq.c:662
__el1_irq arch/arm64/kernel/entry-common.c:472 [inline]
el1_interrupt+0x38/0x68 arch/arm64/kernel/entry-common.c:486
el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:491
el1h_64_irq+0x64/0x68 arch/arm64/kernel/entry.S:587
__daif_local_irq_enable arch/arm64/include/asm/irqflags.h:33 [inline]
arch_local_irq_enable+0x8/0xc arch/arm64/include/asm/irqflags.h:55
cpuidle_idle_call kernel/sched/idle.c:170 [inline]
do_idle+0x1f0/0x4e8 kernel/sched/idle.c:282
cpu_startup_entry+0x24/0x28 kernel/sched/idle.c:379
rest_init+0x2dc/0x2f4 init/main.c:735
start_kernel+0x0/0x55c init/main.c:834
start_kernel+0x3f0/0x55c init/main.c:1088
__primary_switched+0xb8/0xc0 arch/arm64/kernel/head.S:523

Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sched: remove redundant NULL check in change hook function

Currently, the change function can be called by two ways. The one way is
that qdisc_change() will call it. Before calling change function,
qdisc_change() ensures tca[TCA_OPTIONS] is not empty. The other way is
that .init() will call it. The opt parameter is also checked before
calling change function in .init(). Therefore, it's no need to check the
input parameter opt in change function.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://lore.kernel.org/r/20220829071219.208646-1-shaozhengchao@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net: sched: delete duplicate cleanup of backlog and qlen

qdisc_reset() is clearing qdisc->q.qlen and qdisc->qstats.backlog
_after_ calling qdisc->ops->reset. There is no need to clear them
again in the specific reset function.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Link: https://lore.kernel.org/r/20220824005231.345727-1-shaozhengchao@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

net/sched: fq_pie: prevent dismantle issue

For some reason, fq_pie_destroy() did not copy
working code from pie_destroy() and other qdiscs,
thus causing elusive bug.

Before calling del_timer_sync(&q->adapt_timer),
we need to ensure timer will not rearm itself.

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (4416 ticks this GP) idle=60d/1/0x4000000000000000 softirq=10433/10434 fqs=2579
(t=10501 jiffies g=13085 q=3989)
NMI backtrace for cpu 0
CPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343
print_cpu_stall kernel/rcu/tree_stall.h:627 [inline]
check_cpu_stall kernel/rcu/tree_stall.h:711 [inline]
rcu_pending kernel/rcu/tree.c:3878 [inline]
rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597
update_process_times+0x16d/0x200 kernel/time/timer.c:1785
tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
__sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:write_comp_data kernel/kcov.c:221 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x1d/0x80 kernel/kcov.c:273
Code: 54 c8 20 48 89 10 c3 66 0f 1f 44 00 00 53 41 89 fb 41 89 f1 bf 03 00 00 00 65 48 8b 0c 25 40 70 02 00 48 89 ce 4c 8b 54 24 08 <e8> 4e f7 ff ff 84 c0 74 51 48 8b 81 88 15 00 00 44 8b 81 84 15 00
RSP: 0018:ffffc90000d27b28 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888064bf1bf0 RCX: ffff888011928000
RDX: ffff888011928000 RSI: ffff888011928000 RDI: 0000000000000003
RBP: ffff888064bf1c28 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff875d8295 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880783dd300 R14: 0000000000000000 R15: 0000000000000000
pie_calculate_probability+0x405/0x7c0 net/sched/sch_pie.c:418
fq_pie_timer+0x170/0x2a0 net/sched/sch_fq_pie.c:383
call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
expire_timers kernel/time/timer.c:1466 [inline]
__run_timers.part.0+0x675/0xa20 kernel/time/timer.c:1734
__run_timers kernel/time/timer.c:1715 [inline]
run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1747
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558
run_ksoftirqd kernel/softirq.c:921 [inline]
run_ksoftirqd+0x2d/0x60 kernel/softirq.c:913
smpboot_thread_fn+0x645/0x9c0 kernel/smpboot.c:164
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>

Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Mohit P. Tahiliani <tahiliani@nitk.edu.in>
Cc: Sachin D. Patil <sdp.sachin@gmail.com>
Cc: V. Saicharan <vsaicharan1998@gmail.com>
Cc: Mohit Bhasi <mohitbhasi1998@gmail.com>
Cc: Leslie Monis <lesliemonis@gmail.com>
Cc: Gautam Ramakrishnan <gautamramk@gmail.com>
Link: https://lore.kernel.org/r/20211209084937.3500020-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

net/sched: store the last executed chain also for clsact egress

currently, only 'ingress' and 'clsact ingress' qdiscs store the tc 'chain
id' in the skb extension. However, userspace programs (like ovs) are able
to setup egress rules, and datapath gets confused in case it doesn't find
the 'chain id' for a packet that's "recirculated" by tc.
Change tcf_classify() to have the same semantic as tcf_classify_ingress()
so that a single function can be called in ingress / egress, using the tc
ingress / egress block respectively.

Suggested-by: Alaa Hleilel <alaa@nvidia.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched: fq_pie: fix OOB access in the traffic path

the following script:

# tc qdisc add dev eth0 handle 0x1 root fq_pie flows 2
# tc qdisc add dev eth0 clsact
# tc filter add dev eth0 egress matchall action skbedit priority 0x10002
# ping 192.0.2.2 -I eth0 -c2 -w1 -q

produces the following splat:

BUG: KASAN: slab-out-of-bounds in fq_pie_qdisc_enqueue+0x1314/0x19d0 [sch_fq_pie]
Read of size 4 at addr ffff888171306924 by task ping/942

CPU: 3 PID: 942 Comm: ping Not tainted 5.12.0+ #441
Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014
Call Trace:
dump_stack+0x92/0xc1
print_address_description.constprop.7+0x1a/0x150
kasan_report.cold.13+0x7f/0x111
fq_pie_qdisc_enqueue+0x1314/0x19d0 [sch_fq_pie]
__dev_queue_xmit+0x1034/0x2b10
ip_finish_output2+0xc62/0x2120
__ip_finish_output+0x553/0xea0
ip_output+0x1ca/0x4d0
ip_send_skb+0x37/0xa0
raw_sendmsg+0x1c4b/0x2d00
sock_sendmsg+0xdb/0x110
__sys_sendto+0x1d7/0x2b0
__x64_sys_sendto+0xdd/0x1b0
do_syscall_64+0x3c/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe69735c3eb
Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 f3 0f 1e fa 48 8d 05 75 42 2c 00 41 89 ca 8b 00 85 c0 75 14 b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 75 c3 0f 1f 40 00 41 57 4d 89 c7 41 56 41 89
RSP: 002b:00007fff06d7fb38 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000055e961413700 RCX: 00007fe69735c3eb
RDX: 0000000000000040 RSI: 000055e961413700 RDI: 0000000000000003
RBP: 0000000000000040 R08: 000055e961410500 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff06d81260
R13: 00007fff06d7fb40 R14: 00007fff06d7fc30 R15: 000055e96140f0a0

Allocated by task 917:
kasan_save_stack+0x19/0x40
__kasan_kmalloc+0x7f/0xa0
__kmalloc_node+0x139/0x280
fq_pie_init+0x555/0x8e8 [sch_fq_pie]
qdisc_create+0x407/0x11b0
tc_modify_qdisc+0x3c2/0x17e0
rtnetlink_rcv_msg+0x346/0x8e0
netlink_rcv_skb+0x120/0x380
netlink_unicast+0x439/0x630
netlink_sendmsg+0x719/0xbf0
sock_sendmsg+0xe2/0x110
____sys_sendmsg+0x5ba/0x890
___sys_sendmsg+0xe9/0x160
__sys_sendmsg+0xd3/0x170
do_syscall_64+0x3c/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff888171306800
which belongs to the cache kmalloc-256 of size 256
The buggy address is located 36 bytes to the right of
256-byte region [ffff888171306800, ffff888171306900)
The buggy address belongs to the page:
page:00000000bcfb624e refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x171306
head:00000000bcfb624e order:1 compound_mapcount:0
flags: 0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
raw: 0017ffffc0010200 dead000000000100 dead000000000122 ffff888100042b40
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff888171306800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888171306880: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
>ffff888171306900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
^
ffff888171306980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888171306a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

fix fq_pie traffic path to avoid selecting 'q->flows + q->flows_cnt' as a
valid flow: it's an address beyond the allocated memory.

Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
CC: stable@vger.kernel.org
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched: fq_pie: re-factor fix for fq_pie endless loop

the patch that fixed an endless loop in_fq_pie_init() was not considering
that 65535 is a valid class id. The correct bugfix for this infinite loop
is to change 'idx' to become an u32, like Colin proposed in the past [1].

Fix this as follows:
- restore 65536 as maximum possible values of 'flows_cnt'
- use u32 'idx' when iterating on 'q->flows'
- fix the TDC selftest

This reverts commit bb2f930d6dd708469a587dc9ed1efe1ef969c0bf.

[1] https://lore.kernel.org/netdev/20210407163808.499027-1-colin.king@canonical.com/

CC: Colin Ian King <colin.king@canonical.com>
CC: stable@vger.kernel.org
Fixes: bb2f930d6dd7 ("net/sched: fix infinite loop in sch_fq_pie")
Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched: fq_pie: initialize timer earlier in fq_pie_init()

with the following tdc testcase:

83be: (qdisc, fq_pie) Create FQ-PIE with invalid number of flows

as fq_pie_init() fails, fq_pie_destroy() is called to clean up. Since the
timer is not yet initialized, it's possible to observe a splat like this:

INFO: trying to register non-static key.
the code is fine but needs lockdep annotation.
turning off the locking correctness validator.
CPU: 0 PID: 975 Comm: tc Not tainted 5.10.0-rc4+ #298
Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014
Call Trace:
dump_stack+0x99/0xcb
register_lock_class+0x12dd/0x1750
__lock_acquire+0xfe/0x3970
lock_acquire+0x1c8/0x7f0
del_timer_sync+0x49/0xd0
fq_pie_destroy+0x3f/0x80 [sch_fq_pie]
qdisc_create+0x916/0x1160
tc_modify_qdisc+0x3c4/0x1630
rtnetlink_rcv_msg+0x346/0x8e0
netlink_unicast+0x439/0x630
netlink_sendmsg+0x719/0xbf0
sock_sendmsg+0xe2/0x110
____sys_sendmsg+0x5ba/0x890
___sys_sendmsg+0xe9/0x160
__sys_sendmsg+0xd3/0x170
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
[...]
ODEBUG: assert_init not available (active state 0) object type: timer_list hint: 0x0
WARNING: CPU: 0 PID: 975 at lib/debugobjects.c:508 debug_print_object+0x162/0x210
[...]
Call Trace:
debug_object_assert_init+0x268/0x380
try_to_del_timer_sync+0x6a/0x100
del_timer_sync+0x9e/0xd0
fq_pie_destroy+0x3f/0x80 [sch_fq_pie]
qdisc_create+0x916/0x1160
tc_modify_qdisc+0x3c4/0x1630
rtnetlink_rcv_msg+0x346/0x8e0
netlink_rcv_skb+0x120/0x380
netlink_unicast+0x439/0x630
netlink_sendmsg+0x719/0xbf0
sock_sendmsg+0xe2/0x110
____sys_sendmsg+0x5ba/0x890
___sys_sendmsg+0xe9/0x160
__sys_sendmsg+0xd3/0x170
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9

fix it moving timer_setup() before any failure, like it was done on 'red'
with former commit 608b4adab178 ("net_sched: initialize timer earlier in
red_init()").

Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Link: https://lore.kernel.org/r/2e78e01c504c633ebdff18d041833cf2e079a3a4.1607020450.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Revert "net: sched: Pass root lock to Qdisc_ops.enqueue"

This reverts commit aebe4426ccaa4838f36ea805cdf7d76503e65117.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

treewide: Remove uninitialized_var() usage

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
xargs perl -pi -e \
's/\buninitialized_var\(([^\)]+)\)/\1/g;
s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>

net/sched: 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/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sched: Pass root lock to Qdisc_ops.enqueue

A following patch introduces qevents, points in qdisc algorithm where
packet can be processed by user-defined filters. Should this processing
lead to a situation where a new packet is to be enqueued on the same port,
holding the root lock would lead to deadlocks. To solve the issue, qevent
handler needs to unlock and relock the root lock when necessary.

To that end, add the root lock argument to the qdisc op enqueue, and
propagate throughout.

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

net/sched: fix infinite loop in sch_fq_pie

this command hangs forever:

# tc qdisc add dev eth0 root fq_pie flows 65536

watchdog: BUG: soft lockup - CPU#1 stuck for 23s! [tc:1028]
[...]
CPU: 1 PID: 1028 Comm: tc Not tainted 5.7.0-rc6+ #167
RIP: 0010:fq_pie_init+0x60e/0x8b7 [sch_fq_pie]
Code: 4c 89 65 50 48 89 f8 48 c1 e8 03 42 80 3c 30 00 0f 85 2a 02 00 00 48 8d 7d 10 4c 89 65 58 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <0f> 85 a7 01 00 00 48 8d 7d 18 48 c7 45 10 46 c3 23 00 48 89 f8 48
RSP: 0018:ffff888138d67468 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 1ffff9200018d2b2 RBX: ffff888139c1c400 RCX: ffffffffffffffff
RDX: 000000000000c5e8 RSI: ffffc900000e5000 RDI: ffffc90000c69590
RBP: ffffc90000c69580 R08: fffffbfff79a9699 R09: fffffbfff79a9699
R10: 0000000000000700 R11: fffffbfff79a9698 R12: ffffc90000c695d0
R13: 0000000000000000 R14: dffffc0000000000 R15: 000000002347c5e8
FS: 00007f01e1850e40(0000) GS:ffff88814c880000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000067c340 CR3: 000000013864c000 CR4: 0000000000340ee0
Call Trace:
qdisc_create+0x3fd/0xeb0
tc_modify_qdisc+0x3be/0x14a0
rtnetlink_rcv_msg+0x5f3/0x920
netlink_rcv_skb+0x121/0x350
netlink_unicast+0x439/0x630
netlink_sendmsg+0x714/0xbf0
sock_sendmsg+0xe2/0x110
____sys_sendmsg+0x5b4/0x890
___sys_sendmsg+0xe9/0x160
__sys_sendmsg+0xd3/0x170
do_syscall_64+0x9a/0x370
entry_SYSCALL_64_after_hwframe+0x44/0xa9

we can't accept 65536 as a valid number for 'nflows', because the loop on
'idx' in fq_pie_init() will never end. The extack message is correct, but
it doesn't say that 0 is not a valid number for 'flows': while at it, fix
this also. Add a tdc selftest to check correct validation of 'flows'.

CC: Ivan Vecera <ivecera@redhat.com>
Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

pie: remove pie_vars->accu_prob_overflows

The variable pie_vars->accu_prob is used as an accumulator for
probability values. Since probabilty values are scaled using the
MAX_PROB macro denoting (2^64 - 1), pie_vars->accu_prob is
likely to overflow as it is of type u64.

The variable pie_vars->accu_prob_overflows counts the number of
times the variable pie_vars->accu_prob overflows.

The MAX_PROB macro needs to be equal to at least (2^39 - 1) in
order to do precise calculations without any underflow. Thus
MAX_PROB can be reduced to (2^56 - 1) without affecting the
precision in calculations drastically. Doing so will eliminate
the need for the variable pie_vars->accu_prob_overflows as the
variable pie_vars->accu_prob will never overflow.

Removing the variable pie_vars->accu_prob_overflows also reduces
the size of the structure pie_vars to exactly 64 bytes.

Signed-off-by: Mohit P. Tahiliani <tahiliani@nitk.edu.in>
Signed-off-by: Gautam Ramakrishnan <gautamramk@gmail.com>
Signed-off-by: Leslie Monis <lesliemonis@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sched: prevent a use after free

The bug is that we call kfree_skb(skb) and then pass "skb" to
qdisc_pkt_len(skb) on the next line, which is a use after free.
Also Cong Wang points out that it's better to delay the actual
frees until we drop the rtnl lock so we should use rtnl_kfree_skbs()
instead of kfree_skb().

Cc: Cong Wang <xiyou.wangcong@gmail.com>
Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net: sched: add Flow Queue PIE packet scheduler

Principles:
- Packets are classified on flows.
- This is a Stochastic model (as we use a hash, several flows might
be hashed to the same slot)
- Each flow has a PIE managed queue.
- Flows are linked onto two (Round Robin) lists,
so that new flows have priority on old ones.
- For a given flow, packets are not reordered.
- Drops during enqueue only.
- ECN capability is off by default.
- ECN threshold (if ECN is enabled) is at 10% by default.
- Uses timestamps to calculate queue delay by default.

Usage:
tc qdisc ... fq_pie [ limit PACKETS ] [ flows NUMBER ]
[ target TIME ] [ tupdate TIME ]
[ alpha NUMBER ] [ beta NUMBER ]
[ quantum BYTES ] [ memory_limit BYTES ]
[ ecnprob PERCENTAGE ] [ [no]ecn ]
[ [no]bytemode ] [ [no_]dq_rate_estimator ]

defaults:
limit: 10240 packets, flows: 1024
target: 15 ms, tupdate: 15 ms (in jiffies)
alpha: 1/8, beta : 5/4
quantum: device MTU, memory_limit: 32 Mb
ecnprob: 10%, ecn: off
bytemode: off, dq_rate_estimator: off

Signed-off-by: Mohit P. Tahiliani <tahiliani@nitk.edu.in>
Signed-off-by: Sachin D. Patil <sdp.sachin@gmail.com>
Signed-off-by: V. Saicharan <vsaicharan1998@gmail.com>
Signed-off-by: Mohit Bhasi <mohitbhasi1998@gmail.com>
Signed-off-by: Leslie Monis <lesliemonis@gmail.com>
Signed-off-by: Gautam Ramakrishnan <gautamramk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>