[syzbot] [kernel?] WARNING in stub_timer (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9716c086c8e8 Merge tag 'pm-7.1-rc8' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=120533d2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=b4166e8ea5fbf7e3
dashboard link: https://syzkaller.appspot.com/bug?extid=5e8dda76ca21dae314b6
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

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-9716c086.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c42e123755c8/vmlinux-9716c086.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4eb934549042/bzImage-9716c086.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5e8dda...@syzkaller.appspotmail.com

------------[ cut here ]------------
1
WARNING: kernel/time/hrtimer.c:443 at stub_timer+0xa/0x20 kernel/time/timer.c:716, CPU#0: udevd/4706
Modules linked in:
CPU: 0 UID: 0 PID: 4706 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:stub_timer+0xa/0x20 kernel/time/timer.c:716
Code: cc 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa e8 d7 1a 13 00 90 <0f> 0b 90 31 c0 c3 cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90000007dd0 EFLAGS: 00010006
RAX: ffffffff81b2ac39 RBX: 1ffff11000046617 RCX: ffff888000232540
RDX: 0000000000010000 RSI: ffffffff8c28d0c0 RDI: ffffc9000255fb20
RBP: ffffc9000255fb20 R08: ffffffff90305bf7 R09: 1ffffffff2060b7e
R10: dffffc0000000000 R11: ffffffff81b2ac30 R12: ffff8880002330b8
R13: 1ffff11003f8506a R14: dffffc0000000000 R15: ffffffff81b2ac30
FS: 00007f6e41fb1880(0000) GS:ffff88808c894000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005589b464e660 CR3: 00000000128d0000 CR4: 0000000000352ef0
Call Trace:
<IRQ>
__run_hrtimer kernel/time/hrtimer.c:1930 [inline]
__hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 ad 28 f6 f5 f7 c3 00 02 00 00 74 05 e8 20 d2 21 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> c4 a7 e7 f5 65 8b 05 8d 9d 8c 07 85 c0 74 18 5b 41 5e c3 cc cc
RSP: 0018:ffffc9000255fac8 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000246 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8dfa9d91 RDI: 0000000000000001
RBP: ffffc9000255fbf0 R08: ffffffff90305bf7 R09: 1ffffffff2060b7e
R10: dffffc0000000000 R11: fffffbfff2060b7f R12: 1ffff920004abfae
R13: 1ffff920004abf60 R14: ffff88801fc28280 R15: dffffc0000000000
schedule_hrtimeout_range_clock+0x142/0x330 kernel/time/sleep_timeout.c:213
ep_poll fs/eventpoll.c:2030 [inline]
do_epoll_wait+0xd36/0xf60 fs/eventpoll.c:2464
__do_sys_epoll_wait fs/eventpoll.c:2472 [inline]
__se_sys_epoll_wait fs/eventpoll.c:2467 [inline]
__x64_sys_epoll_wait+0x1d7/0x230 fs/eventpoll.c:2467
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6e418a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffe8bec5c00 EFLAGS: 00000202 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 00007f6e41fb1880 RCX: 00007f6e418a7407
RDX: 0000000000000008 RSI: 00007ffe8bec5d60 RDI: 000000000000000b
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000bb8 R11: 0000000000000202 R12: 0000000000000000
R13: 0000556a1ef48100 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
Code disassembly (best guess):
0: f7 e8 imul %eax
2: ad lods %ds:(%rsi),%eax
3: 28 f6 sub %dh,%dh
5: f5 cmc
6: f7 c3 00 02 00 00 test $0x200,%ebx
c: 74 05 je 0x13
e: e8 20 d2 21 f6 call 0xf621d233
13: 9c pushf
14: 58 pop %rax
15: a9 00 02 00 00 test $0x200,%eax
1a: 75 27 jne 0x43
1c: f7 c3 00 02 00 00 test $0x200,%ebx
22: 74 01 je 0x25
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 c4 a7 e7 f5 call 0xf5e7a7f3 <-- trapping instruction
2f: 65 8b 05 8d 9d 8c 07 mov %gs:0x78c9d8d(%rip),%eax # 0x78c9dc3
36: 85 c0 test %eax,%eax
38: 74 18 je 0x52
3a: 5b pop %rbx
3b: 41 5e pop %r14
3d: c3 ret
3e: cc int3
3f: cc int3


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup