[syzbot] [wireguard?] WARNING in stub_timer

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 54e82e93ca93 Merge tag 'core_urgent_for_v6.19_rc4' of git:..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1022ee22580000
kernel config: https://syzkaller.appspot.com/x/.config?x=513255d80ab78f2b
dashboard link: https://syzkaller.appspot.com/bug?extid=19e796f043fe3be7b76a
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-54e82e93.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f3befb5f53a4/vmlinux-54e82e93.xz
kernel image: https://storage.googleapis.com/syzbot-assets/92820ca1dbd8/bzImage-54e82e93.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+19e796...@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: kernel/time/timer.c:716 at stub_timer+0xa/0x20 kernel/time/timer.c:716, CPU#0: kworker/0:1/10
Modules linked in:
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Workqueue: events_power_efficient wg_ratelimiter_gc_entries
RIP: 0010:stub_timer+0xa/0x20 kernel/time/timer.c:716
Code: 0f 94 c0 5b 41 5e e9 05 73 b0 09 cc 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa e8 27 fa 12 00 90 <0f> 0b 90 c3 cc cc cc cc cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90000007c98 EFLAGS: 00010246
RAX: ffffffff81ae0d39 RBX: 0000000000000101 RCX: ffff88801bef0000
RDX: 0000000000000100 RSI: ffffffff8bc095c0 RDI: ffffc9000db0f1c0
RBP: ffffc90000007d90 R08: ffffffff8f824677 R09: 1ffffffff1f048ce
R10: dffffc0000000000 R11: ffffffff81ae0d30 R12: 0000000000000000
R13: ffffc9000db0f1c0 R14: 1ffff92000000f98 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff88808d414000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2cc5528910 CR3: 00000000377e7000 CR4: 0000000000352ef0
Call Trace:
<IRQ>
call_timer_fn+0x16e/0x590 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2373 [inline]
__run_timer_base+0x61a/0x860 kernel/time/timer.c:2385
run_timer_base kernel/time/timer.c:2394 [inline]
run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2404
handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0x60/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2d8/0x3b0 kernel/locking/lockdep.c:5893
Code: e4 e2 10 00 00 00 00 eb b5 e8 84 7f bd 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 74 9e e2 10 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 59 5e c0 09 cc 48 8d 3d 11 6d e7
RSP: 0018:ffffc900001c79e0 EFLAGS: 00000282
RAX: f62d7e25cf48d100 RBX: 0000000000000283 RCX: 0000000080000001
RDX: 0000000000000002 RSI: ffffffff8d97c93e RDI: ffffffff8bc095e0
RBP: ffff88801bef0b80 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000038f34 R12: 0000000000000002
R13: 0000000000000002 R14: ffffffff8ea6eef8 R15: ffff88801bef0000
__raw_spin_unlock include/linux/spinlock_api_smp.h:141 [inline]
_raw_spin_unlock+0x16/0x50 kernel/locking/spinlock.c:186
spin_unlock include/linux/spinlock.h:391 [inline]
wg_ratelimiter_gc_entries+0x384/0x450 drivers/net/wireguard/ratelimiter.c:76
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
----------------
Code disassembly (best guess):
0: e4 e2 in $0xe2,%al
2: 10 00 adc %al,(%rax)
4: 00 00 add %al,(%rax)
6: 00 eb add %ch,%bl
8: b5 e8 mov $0xe8,%ch
a: 84 7f bd test %bh,-0x43(%rdi)
d: 09 f7 or %esi,%edi
f: c3 ret
10: 00 02 add %al,(%rdx)
12: 00 00 add %al,(%rax)
14: 74 b9 je 0xffffffcf
16: 65 48 8b 05 74 9e e2 mov %gs:0x10e29e74(%rip),%rax # 0x10e29e92
1d: 10
1e: 48 3b 44 24 28 cmp 0x28(%rsp),%rax
23: 75 44 jne 0x69
25: fb sti
26: 48 83 c4 30 add $0x30,%rsp
* 2a: 5b pop %rbx <-- trapping instruction
2b: 41 5c pop %r12
2d: 41 5d pop %r13
2f: 41 5e pop %r14
31: 41 5f pop %r15
33: 5d pop %rbp
34: e9 59 5e c0 09 jmp 0x9c05e92
39: cc int3
3a: 48 rex.W
3b: 8d .byte 0x8d
3c: 3d .byte 0x3d
3d: 11 6d e7 adc %ebp,-0x19(%rbp)


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