syzbot


WARNING in call_timer_fn

Status: upstream: reported syz repro on 2025/06/17 20:10
Reported-by: syzbot+4ec2f23cfdd215d89b91@syzkaller.appspotmail.com
First crash: 71d, last: 6d08h
Bug presence (1)
Date Name Commit Repro Result
2025/06/26 upstream (ToT) e34a79b96ab9 syz Didn't crash
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in call_timer_fn bluetooth -1 C unreliable 7237 5h27m 1015d 0/29 upstream: reported C repro on 2022/11/16 15:25
linux-5.15 WARNING in call_timer_fn (2) -1 4 74d 99d 0/3 upstream: reported on 2025/05/20 15:59
linux-6.1 WARNING in call_timer_fn origin:lts-only -1 C unreliable 186 6d12h 903d 0/3 upstream: reported C repro on 2023/03/08 12:11
linux-5.15 WARNING in call_timer_fn origin:lts-only -1 syz unreliable 7 297d 553d 0/3 auto-obsoleted due to no activity on 2025/02/11 06:36

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5793 at kernel/workqueue.c:1726 is_chained_work kernel/workqueue.c:1672 [inline]
WARNING: CPU: 1 PID: 5793 at kernel/workqueue.c:1726 __queue_work+0xd49/0x1020 kernel/workqueue.c:1725
Modules linked in:
CPU: 1 PID: 5793 Comm: kworker/u5:5 Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: hci0 wq_barrier_func
RIP: 0010:__queue_work+0xd49/0x1020 kernel/workqueue.c:1725
Code: 4c 89 f7 48 89 de 89 e9 e8 d4 e3 00 00 48 8b 5c 24 10 e9 10 ff ff ff e8 95 1c 2f 00 eb 0c e8 8e 1c 2f 00 eb 05 e8 87 1c 2f 00 <0f> 0b 48 83 c4 78 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 71 1c 2f 00
RSP: 0018:ffffc900001f0b10 EFLAGS: 00010046
RAX: ffffffff81566e8b RBX: 0000000000000100 RCX: ffff88807aed8000
RDX: 0000000000000100 RSI: 0000000000000100 RDI: 0000000000000000
RBP: ffff888024d741c0 R08: ffffffff8e4a882f R09: 1ffffffff1c95105
R10: dffffc0000000000 R11: fffffbfff1c95106 R12: 0000000000000008
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff888024d74000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056175a5b3fb0 CR3: 000000000cb30000 CR4: 00000000003506e0
Call Trace:
 <IRQ>
 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1746 [inline]
 __run_timers+0x558/0x7d0 kernel/time/timer.c:2022
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 2a fe 14 f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> a2 7a e4 f6 65 8b 05 c3 c9 8c 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90004657b20 EFLAGS: 00000206
RAX: 58d21d2d95214c00 RBX: 0000000000000a06 RCX: 58d21d2d95214c00
RDX: dffffc0000000000 RSI: ffffffff8aaab9c0 RDI: 0000000000000001
RBP: ffffc90004657bb0 R08: ffffffff90da3537 R09: 1ffffffff21b46a6
R10: dffffc0000000000 R11: fffffbfff21b46a7 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffffc900045c7910 R15: 1ffff920008caf64
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
----------------
Code disassembly (best guess):
   0:	74 05                	je     0x7
   2:	e8 2a fe 14 f7       	call   0xf714fe31
   7:	48 c7 44 24 20 00 00 	movq   $0x0,0x20(%rsp)
   e:	00 00
  10:	9c                   	pushf
  11:	8f 44 24 20          	pop    0x20(%rsp)
  15:	f6 44 24 21 02       	testb  $0x2,0x21(%rsp)
  1a:	75 4b                	jne    0x67
  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 a2 7a e4 f6       	call   0xf6e47ad1 <-- trapping instruction
  2f:	65 8b 05 c3 c9 8c 75 	mov    %gs:0x758cc9c3(%rip),%eax        # 0x758cc9f9
  36:	85 c0                	test   %eax,%eax
  38:	74 3c                	je     0x76
  3a:	48                   	rex.W
  3b:	c7                   	.byte 0xc7
  3c:	04 24                	add    $0x24,%al
  3e:	0e                   	(bad)
  3f:	36                   	ss

Crashes (18):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/21 18:13 linux-6.6.y bb9c90ab9c5a 3e79b825 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in call_timer_fn
2025/07/29 17:39 linux-6.6.y dbcb8d8e4163 c4a95487 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in call_timer_fn
2025/07/17 08:52 linux-6.6.y 9247f4e6573a 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in call_timer_fn
2025/07/16 08:24 linux-6.6.y 9247f4e6573a 124ec9cc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf WARNING in call_timer_fn
2025/07/09 10:22 linux-6.6.y a5df3a702b2c f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in call_timer_fn
2025/07/09 09:28 linux-6.6.y a5df3a702b2c f4e5e155 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf WARNING in call_timer_fn
2025/07/04 16:10 linux-6.6.y 3f5b4c104b7d d869b261 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf WARNING in call_timer_fn
2025/07/02 01:09 linux-6.6.y 3f5b4c104b7d 091a06cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in call_timer_fn
2025/07/01 14:49 linux-6.6.y 3f5b4c104b7d 091a06cd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf WARNING in call_timer_fn
2025/06/26 16:59 linux-6.6.y 6282921b6825 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in call_timer_fn
2025/06/24 03:00 linux-6.6.y 6282921b6825 e2f27c35 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf WARNING in call_timer_fn
2025/06/23 04:55 linux-6.6.y 6282921b6825 d6cdfb8a .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-6-6-kasan WARNING in call_timer_fn
2025/06/22 21:30 linux-6.6.y 6282921b6825 d6cdfb8a .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf WARNING in call_timer_fn
2025/06/21 16:52 linux-6.6.y 6282921b6825 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in call_timer_fn
2025/06/21 14:33 linux-6.6.y 6282921b6825 d6cdfb8a .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf WARNING in call_timer_fn
2025/06/19 16:20 linux-6.6.y 6282921b6825 ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan WARNING in call_timer_fn
2025/06/19 00:12 linux-6.6.y c2603c511feb ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf WARNING in call_timer_fn
2025/06/17 20:09 linux-6.6.y c2603c511feb e77fae15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf WARNING in call_timer_fn
* Struck through repros no longer work on HEAD.