WARNING in dev_watchdog

Status: upstream: reported C repro on 2023/03/10 20:16
Bug presence: origin:lts-only
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+2c8f0024310bcf69a3af@syzkaller.appspotmail.com
First crash: 1291d, last: 1d12h
Bug presence (2)
Date Name Commit Repro Result
2024/01/25 linux-5.15.y (ToT) ddcaf4999061 C [report] WARNING in dev_watchdog
2024/01/25 upstream (ToT) 6098d87eaf31 C Didn't crash
Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in dev_watchdog (5) net -1 1 495d 495d 0/29 closed as invalid on 2025/07/02 15:51
upstream WARNING in dev_watchdog (3) net -1 1 779d 779d 0/29 closed as invalid on 2024/09/04 18:18
upstream WARNING in dev_watchdog (2) net -1 syz, C inconclusive 6791 967d 2366d 25/29 fixed on 2024/01/30 15:47
upstream WARNING in dev_watchdog (4) net -1 1 584d 584d 0/29 closed as invalid on 2025/03/17 11:07
linux-6.1 WARNING in dev_watchdog origin:upstream missing-backport -1 syz, C inconclusive 149 753d 1290d 0/3 upstream: reported C repro on 2023/03/11 19:14
upstream WARNING in dev_watchdog -1 25 3292d 3316d 0/29 closed as invalid on 2017/10/22 12:45
upstream WARNING in dev_watchdog (6) net -1 1 319d 319d 0/29 closed as invalid on 2026/01/09 17:04
Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/06/06 06:30 17m retest repro linux-5.15.y report log
2026/06/06 06:30 20m retest repro linux-5.15.y report log
2026/06/06 06:30 22m retest repro linux-5.15.y report log
2026/06/06 06:30 23m retest repro linux-5.15.y report log
2026/06/06 06:30 24m retest repro linux-5.15.y report log
2026/05/15 04:45 16m retest repro linux-5.15.y report log
2026/05/15 04:45 22m retest repro linux-5.15.y report log
2026/05/15 04:45 16m retest repro linux-5.15.y report log
2026/05/15 04:45 23m retest repro linux-5.15.y report log
2026/05/15 04:45 23m retest repro linux-5.15.y report log
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2024/03/22 16:56 2h47m fix candidate upstream OK (0) job log
2024/01/23 20:36 0m fix candidate upstream error job log

Sample crash report:
------------[ cut here ]------------
NETDEV WATCHDOG: sl0 (): transmit queue 0 timed out
WARNING: CPU: 1 PID: 0 at net/sched/sch_generic.c:481 dev_watchdog+0x8d3/0xab0 net/sched/sch_generic.c:480
Modules linked in:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:dev_watchdog+0x8d3/0xab0 net/sched/sch_generic.c:480
Code: f9 c6 05 8d da 74 05 01 4c 8b 74 24 28 4c 89 f7 e8 e2 f6 e3 ff 48 c7 c7 80 46 22 8b 4c 89 f6 48 89 c2 44 89 e1 e8 3d 61 b0 01 <0f> 0b e9 31 fe ff ff e8 e1 bd 77 f9 0f 0b e9 13 fe ff ff 44 89 e1
RSP: 0018:ffffc90000dd0b08 EFLAGS: 00010246
RAX: 758de14e1d4c1700 RBX: dffffc0000000000 RCX: ffff8880179c8000
RDX: 0000000000000100 RSI: 0000000000000102 RDI: 0000000000000000
RBP: ffff888025ba8c68 R08: ffffc90000dd0627 R09: 1ffff920001ba0c4
R10: dffffc0000000000 R11: fffff520001ba0c5 R12: 0000000000000000
R13: ffff88807d424540 R14: ffff88807d424000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000000c0 CR3: 000000002ab00000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x53e/0x800 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 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:default_idle+0xb/0x10 arch/x86/kernel/process.c:730
Code: b7 48 89 df e8 f6 3a f8 f7 eb ad e8 4f af f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d 97 b5 5f 00 fb f4 <c3> 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48
RSP: 0018:ffffc90000d67d48 EFLAGS: 000002c2
RAX: 758de14e1d4c1700 RBX: ffff8880179c8000 RCX: 758de14e1d4c1700
RDX: 0000000000000001 RSI: ffffffff8a2b3100 RDI: ffffffff8a7a0700
RBP: ffffc90000d67e80 R08: ffff8880b913b30b R09: 1ffff11017227661
R10: dffffc0000000000 R11: ffffed1017227662 R12: 1ffff920001acfb4
R13: dffffc0000000000 R14: 1ffff11002f39000 R15: 0000000000000000
 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:202 [inline]
 do_idle+0x3a1/0x650 kernel/sched/idle.c:326
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:424
 start_secondary+0x330/0x430 arch/x86/kernel/smpboot.c:281
 secondary_startup_64_no_verify+0xb1/0xbb
 </TASK>
----------------
Code disassembly (best guess):
   0:	b7 48                	mov    $0x48,%bh
   2:	89 df                	mov    %ebx,%edi
   4:	e8 f6 3a f8 f7       	call   0xf7f83aff
   9:	eb ad                	jmp    0xffffffb8
   b:	e8 4f af f6 ff       	call   0xfff6af5f
  10:	00 00                	add    %al,(%rax)
  12:	cc                   	int3
  13:	cc                   	int3
  14:	00 00                	add    %al,(%rax)
  16:	cc                   	int3
  17:	cc                   	int3
  18:	00 00                	add    %al,(%rax)
  1a:	cc                   	int3
  1b:	cc                   	int3
  1c:	00 00                	add    %al,(%rax)
  1e:	cc                   	int3
  1f:	66 90                	xchg   %ax,%ax
  21:	0f 00 2d 97 b5 5f 00 	verw   0x5fb597(%rip)        # 0x5fb5bf
  28:	fb                   	sti
  29:	f4                   	hlt
* 2a:	c3                   	ret <-- trapping instruction
  2b:	0f 1f 40 00          	nopl   0x0(%rax)
  2f:	41 57                	push   %r15
  31:	41 56                	push   %r14
  33:	53                   	push   %rbx
  34:	49 be 00 00 00 00 00 	movabs $0xdffffc0000000000,%r14
  3b:	fc ff df
  3e:	65                   	gs
  3f:	48                   	rex.W

Crashes (564):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/19 19:51 linux-5.15.y 93741761e5e3 223544dc .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/04/22 02:47 linux-5.15.y b9d57c40a767 0b6ab7ec .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2025/09/20 03:57 linux-5.15.y 43bb85222e53 67c37560 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2025/06/20 11:35 linux-5.15.y 1c700860e8bc ed3e87f7 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2024/01/25 08:15 linux-5.15.y ddcaf4999061 1e153dc8 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2023/06/23 04:59 linux-5.15.y f67653019430 79782afc .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2024/09/22 00:19 linux-5.15.y 3a5928702e71 6f888b75 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING in dev_watchdog
2024/09/18 14:55 linux-5.15.y 3a5928702e71 c673ca06 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING in dev_watchdog
2024/05/19 14:26 linux-5.15.y 83655231580b c0f1611a .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING in dev_watchdog
2024/04/22 17:22 linux-5.15.y c52b9710c83d 36c961ad .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING in dev_watchdog
2023/10/13 12:17 linux-5.15.y 02e21884dcf2 6388bc36 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING in dev_watchdog
2023/05/28 20:55 linux-5.15.y 1fe619a7d252 cf184559 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING in dev_watchdog
2026/09/20 13:31 linux-5.15.y 0248c33e835e 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/18 08:05 linux-5.15.y 0248c33e835e 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/18 08:05 linux-5.15.y 0248c33e835e 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/17 17:24 linux-5.15.y 0248c33e835e 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/16 23:42 linux-5.15.y 0248c33e835e 95928915 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/16 05:23 linux-5.15.y 0248c33e835e 12a0a44a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/15 15:16 linux-5.15.y 0248c33e835e 2daa4bb5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/14 15:03 linux-5.15.y 0248c33e835e 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/14 15:01 linux-5.15.y 0248c33e835e 81a27d1a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/14 12:46 linux-5.15.y 0248c33e835e 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/13 00:42 linux-5.15.y 0996e0926f6b 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/12 22:38 linux-5.15.y 0996e0926f6b 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/12 02:09 linux-5.15.y 0996e0926f6b 70a60e12 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/11 11:51 linux-5.15.y 0996e0926f6b b6a5eeb7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/10 11:17 linux-5.15.y 0996e0926f6b 1fe56c0a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/09 18:03 linux-5.15.y 0996e0926f6b 4e8b1cc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/09 05:08 linux-5.15.y 0996e0926f6b 8387c273 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/08 15:36 linux-5.15.y 0996e0926f6b 243b72f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/07 12:27 linux-5.15.y 0996e0926f6b 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/04 23:31 linux-5.15.y 0996e0926f6b 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/04 23:29 linux-5.15.y 0996e0926f6b 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/04 10:28 linux-5.15.y 0996e0926f6b f65209a4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/03 21:28 linux-5.15.y 0996e0926f6b 801f0966 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/03 04:25 linux-5.15.y 0996e0926f6b 6a988719 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/02 15:52 linux-5.15.y 0996e0926f6b 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/02 13:38 linux-5.15.y 28c35638ec51 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/02 13:38 linux-5.15.y 28c35638ec51 85995287 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/09/01 11:45 linux-5.15.y 28c35638ec51 587f6b29 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/31 16:57 linux-5.15.y 28c35638ec51 316d9396 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/29 21:43 linux-5.15.y 28c35638ec51 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/28 21:27 linux-5.15.y 28c35638ec51 2f52988a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/28 09:10 linux-5.15.y 28c35638ec51 e2fa417d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/28 07:55 linux-5.15.y 28c35638ec51 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/28 07:53 linux-5.15.y 28c35638ec51 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/27 15:06 linux-5.15.y 4a1eaf96ee5c 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/27 11:11 linux-5.15.y 945fa863f02c 69a01293 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/26 13:35 linux-5.15.y 945fa863f02c a2b77b9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/26 01:21 linux-5.15.y 945fa863f02c 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/26 01:21 linux-5.15.y 945fa863f02c 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/25 12:21 linux-5.15.y 945fa863f02c a9a1fc32 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/25 00:03 linux-5.15.y 945fa863f02c 614e416a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/24 11:34 linux-5.15.y 945fa863f02c b55bd4c3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2026/08/23 14:13 linux-5.15.y 945fa863f02c 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
2025/08/12 00:31 linux-5.15.y c79648372d02 c06e8995 .config console log report [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING in dev_watchdog
2024/12/20 20:34 linux-5.15.y 91786f140358 0f61b415 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 WARNING in dev_watchdog
2023/03/10 20:16 linux-5.15.y abddfcf701a5 5205ef30 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in dev_watchdog
* Struck through repros no longer work on HEAD.