[v5.15] INFO: rcu detected stall in fq_pie_timer

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9d6bde853685 Linux 5.15.112
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=103471d9280000
kernel config: https://syzkaller.appspot.com/x/.config?x=a61e8195d8bdf36e
dashboard link: https://syzkaller.appspot.com/bug?extid=d7d5aab0ec13e6e303c5
compiler: Debian clang version 15.0.7, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=112aa01e280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16321ab1280000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b65d6c2ec328/disk-9d6bde85.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/cf811ebac37b/vmlinux-9d6bde85.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b2f32fdecf97/bzImage-9d6bde85.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d7d5aa...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-....: (1 GPs behind) idle=699/1/0x4000000000000000 softirq=6015/6018 fqs=38
(t=10500 jiffies g=5521 q=1441)
NMI backtrace for cpu 0
CPU: 0 PID: 3553 Comm: kworker/0:0 Not tainted 5.15.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023
Workqueue: wg-crypt-wg0 wg_packet_encrypt_worker
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_dump_cpu_stacks+0x223/0x390 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:3888 [inline]
rcu_sched_clock_irq+0xf26/0x1770 kernel/rcu/tree.c:2606
update_process_times+0x196/0x200 kernel/time/timer.c:1788
tick_sched_handle kernel/time/tick-sched.c:226 [inline]
tick_sched_timer+0x22d/0x3c0 kernel/time/tick-sched.c:1430
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
__sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
sysvec_apic_timer_interrupt+0x3e/0xb0 arch/x86/kernel/apic/apic.c:1096
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:pie_calculate_probability+0x50c/0x820 net/sched/sch_pie.c:411
Code: 03 42 0f b6 04 30 84 c0 0f 85 7b 02 00 00 44 89 3b 48 8b 44 24 58 42 80 3c 30 00 48 8b 5c 24 08 74 08 48 89 df e8 04 ee 60 f9 <48> 8b 1b 48 d1 eb 4c 89 ef 48 89 de e8 53 94 17 f9 49 39 dd 73 5c
RSP: 0018:ffffc90000007b50 EFLAGS: 00000246
RAX: 1ffff1100fcce360 RBX: ffff88807e671b00 RCX: ffff888022181dc0
RDX: 0000000000000102 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff88806a5b4140 R08: ffffffff886855b0 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: ffff88806a5b4128
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000000
fq_pie_timer+0x132/0x260 net/sched/sch_fq_pie.c:383
call_timer_fn+0x16d/0x560 kernel/time/timer.c:1421
expire_timers kernel/time/timer.c:1466 [inline]
__run_timers+0x67c/0x890 kernel/time/timer.c:1737
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1750
__do_softirq+0x3b3/0x93a kernel/softirq.c:558
do_softirq+0x162/0x240 kernel/softirq.c:459
</IRQ>
<TASK>
__local_bh_enable_ip+0x1b1/0x1f0 kernel/softirq.c:383
spin_unlock_bh include/linux/spinlock.h:408 [inline]
ptr_ring_consume_bh include/linux/ptr_ring.h:367 [inline]
wg_packet_encrypt_worker+0x2d3/0x1590 drivers/net/wireguard/send.c:293
process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2307
worker_thread+0xaca/0x1280 kernel/workqueue.c:2454
kthread+0x3f6/0x4f0 kernel/kthread.c:319
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
</TASK>


---
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[syzbot]

syzbot suspects this issue could be fixed by backporting the following commit:

commit f85fa45d4a9408d98c46c8fa45ba2e3b2f4bf219
git tree: upstream
Author: Peilin Ye <peil...@bytedance.com>
Date: Mon May 29 19:54:03 2023 +0000

net/sched: Reserve TC_H_INGRESS (TC_H_CLSACT) for ingress (clsact) Qdiscs

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=17b27d64e80000

kernel config: https://syzkaller.appspot.com/x/.config?x=a61e8195d8bdf36e
dashboard link: https://syzkaller.appspot.com/bug?extid=d7d5aab0ec13e6e303c5

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=112aa01e280000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16321ab1280000

Please keep in mind that other backports might be required as well.

For information about bisection process see: https://goo.gl/tpsmEJ#bisection