syzbot


WARNING in call_timer_fn (2)

Status: upstream: reported on 2025/05/20 15:59
Reported-by: syzbot+97c9d96f4cf6e2f67ce5@syzkaller.appspotmail.com
First crash: 103d, last: 2d14h
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 WARNING in call_timer_fn -1 syz 18 10d 75d 0/2 upstream: reported syz repro on 2025/06/17 20:10
upstream WARNING in call_timer_fn bluetooth -1 C unreliable 7252 47m 1019d 0/29 upstream: reported C repro on 2022/11/16 15:25
linux-6.1 WARNING in call_timer_fn origin:lts-only -1 C unreliable 186 10d 908d 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 302d 558d 0/3 auto-obsoleted due to no activity on 2025/02/11 06:36

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 5961 at kernel/workqueue.c:1453 __queue_work+0xc04/0xd50 kernel/workqueue.c:1453
Modules linked in:
CPU: 1 PID: 5961 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__queue_work+0xc04/0xd50 kernel/workqueue.c:1453
Code: fc ff ff 48 8b 4c 24 08 80 e1 07 80 c1 03 38 c1 0f 8c 13 fd ff ff 48 8b 7c 24 08 e8 56 1c 6f 00 e9 04 fd ff ff e8 2c b6 2a 00 <0f> 0b 48 83 c4 50 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 16 b6 2a 00
RSP: 0018:ffffc90000dd0b18 EFLAGS: 00010046
RAX: ffffffff814d1484 RBX: 0000000000010000 RCX: ffff888021870000
RDX: 0000000000000100 RSI: 0000000000000100 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ad3196
R10: fffffbfff1ad3196 R11: 1ffffffff1ad3195 R12: ffff88805bdcc180
R13: ffff888022e8f1c0 R14: ffff888022e8f000 R15: 0000000000000008
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000217000 CR3: 0000000062c4d000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1491 [inline]
 __run_timers+0x550/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc900030cf880 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 33ab77c3787e4800
RDX: ffffffff8f9b84f0 RSI: ffffffff8a0b28c0 RDI: ffffffff8a59a240
RBP: ffffc900030cf988 R08: dffffc0000000000 R09: fffffbfff250b47c
R10: fffffbfff250b47c R11: 1ffffffff250b47b R12: ffff888022e8f138
R13: 1ffff92000619f1c R14: 0000000000000246 R15: dffffc0000000000
 flush_workqueue+0x142/0x1380 kernel/workqueue.c:2830
 drain_workqueue+0xcf/0x380 kernel/workqueue.c:2995
 hci_dev_do_close+0x3e3/0x1030 net/bluetooth/hci_core.c:1780
 hci_unregister_dev+0x2d7/0x580 net/bluetooth/hci_core.c:4040
 vhci_release+0x73/0xc0 drivers/bluetooth/hci_vhci.c:345
 __fput+0x234/0x930 fs/file_table.c:311
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 exit_task_work include/linux/task_work.h:33 [inline]
 do_exit+0x61e/0x20a0 kernel/exit.c:883
 do_group_exit+0x12e/0x300 kernel/exit.c:997
 __do_sys_exit_group kernel/exit.c:1008 [inline]
 __se_sys_exit_group kernel/exit.c:1006 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1006
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f21263ddbe9
Code: Unable to access opcode bytes at RIP 0x7f21263ddbbf.
RSP: 002b:00007ffd4388f5f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000007 RCX: 00007f21263ddbe9
RDX: 00007f21263dfada RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007ffd4388fc60 R08: 00007ffd4388fff7 R09: 0000000000000007
R10: 0000000000000408 R11: 0000000000000246 R12: 00007ffd4388fc0c
R13: 00000000000927c0 R14: 000000000003f8a4 R15: 00007ffd43890340
 </TASK>
----------------
Code disassembly (best guess):
   0:	00 9c 8f 84 24 80 00 	add    %bl,0x802484(%rdi,%rcx,4)
   7:	00 00                	add    %al,(%rax)
   9:	f6 84 24 81 00 00 00 	testb  $0x2,0x81(%rsp)
  10:	02
  11:	0f 85 f6 00 00 00    	jne    0x10d
  17:	41 f7 c6 00 02 00 00 	test   $0x200,%r14d
  1e:	74 01                	je     0x21
  20:	fb                   	sti
  21:	48 c7 44 24 60 0e 36 	movq   $0x45e0360e,0x60(%rsp)
  28:	e0 45
* 2a:	4b c7 44 3d 00 00 00 	movq   $0x0,0x0(%r13,%r15,1) <-- trapping instruction
  31:	00 00
  33:	66 43 c7 44 3d 09 00 	movw   $0x0,0x9(%r13,%r15,1)
  3a:	00
  3b:	43                   	rex.XB
  3c:	c6                   	.byte 0xc6
  3d:	44                   	rex.R
  3e:	3d                   	.byte 0x3d
  3f:	0b                   	.byte 0xb

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/29 22:58 linux-5.15.y 01879f56bdde 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf WARNING in call_timer_fn
2025/06/14 02:42 linux-5.15.y 1c700860e8bc 0e8da31f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf WARNING in call_timer_fn
2025/06/11 15:23 linux-5.15.y 1c700860e8bc 5d7e17ca .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in call_timer_fn
2025/05/29 07:46 linux-5.15.y 98f47d0e9b8c 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in call_timer_fn
2025/05/20 15:59 linux-5.15.y a68c15152131 b47f9e02 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in call_timer_fn
* Struck through repros no longer work on HEAD.