syzbot


WARNING in update_rq_clock (2)

Status: upstream: reported on 2026/07/03 00:38
Subsystems: kernel
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+681e729b2cf0d4860042@syzkaller.appspotmail.com
First crash: 16d, last: 1d02h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
48fadd05-2592-42b2-bd5f-8900be6d2016 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in update_rq_clock (2) 2026/07/01 00:35 2026/07/01 00:35 2026/07/01 01:15 93f579545ae410f5bccfa141d2e7bf03178f036c

			
		
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] WARNING in update_rq_clock (2) 3 (4) 2026/07/03 10:08
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in update_rq_clock fs -1 23 131d 222d 0/29 auto-obsoleted due to no activity on 2026/05/15 14:56

Sample crash report:
------------[ cut here ]------------
debug_locks && !(lock_is_held(&(__rq_lockp(rq))->dep_map) != 0)
WARNING: kernel/sched/sched.h:1641 at lockdep_assert_rq_held kernel/sched/sched.h:1641 [inline], CPU#0: syz.2.219/6975
WARNING: kernel/sched/sched.h:1641 at lockdep_assert_rq_held kernel/sched/sched.h:1638 [inline], CPU#0: syz.2.219/6975
WARNING: kernel/sched/sched.h:1641 at update_rq_clock+0x40a/0xd20 kernel/sched/core.c:865, CPU#0: syz.2.219/6975
Modules linked in:
CPU: 0 UID: 0 PID: 6975 Comm: syz.2.219 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1641 [inline]
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1638 [inline]
RIP: 0010:update_rq_clock+0x40a/0xd20 kernel/sched/core.c:865
Code: ab c8 0b 00 00 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e 41 5f e9 58 9e e4 09 a8 04 0f 84 df fc ff ff 90 0f 0b 90 e9 d6 fc ff ff 90 <0f> 0b 90 e9 92 fc ff ff 4c 8d 83 c0 0b 00 00 48 b8 00 00 00 00 00
RSP: 0018:ffffc90002d97810 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8880b853b600 RCX: 0000000000000001
RDX: 0000000000000046 RSI: ffffffff8e180820 RDI: ffffffff8c400380
RBP: ffffc90002d979b8 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff91226597 R11: 0000000000000000 R12: ffffffff91229944
R13: ffff8880b853c4e0 R14: ffff88801eac9f00 R15: ffff8880b843c198
FS:  00007fedf31dd6c0(0000) GS:ffff888123df1000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000e67000 CR3: 000000007a6b8000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 pick_next_task kernel/sched/core.c:6338 [inline]
 __schedule+0x1e2d/0x6730 kernel/sched/core.c:7149
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556
 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x205/0xa00 kernel/entry/common.c:167
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:679
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: f6 e8 5d 00 48 89 df 5b e9 7d 63 63 00 be 03 00 00 00 5b e9 52 af 11 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 65 8b 05 65 c7 59 12 48 8b 34 24 65 48 8b 15 41 c7 59
RSP: 0018:ffffc90002d97ad8 EFLAGS: 00000246
RAX: 0000000000080000 RBX: 0000000000000000 RCX: ffffc9000652a000
RDX: 0000000000080000 RSI: ffffffff81cec75b RDI: ffff88802eee5d00
RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000008
R13: ffff88801bc06c00 R14: ffff8880334a3600 R15: 0000000000001000
 queue_work_on+0x141/0x1e0 kernel/workqueue.c:2457
 queue_work include/linux/workqueue.h:699 [inline]
 snd_virmidi_output_trigger+0xf6/0x140 sound/core/seq/seq_virmidi.c:178
 snd_rawmidi_output_trigger sound/core/rawmidi.c:213 [inline]
 snd_rawmidi_output_trigger sound/core/rawmidi.c:209 [inline]
 snd_rawmidi_kernel_write1+0x51f/0x7c0 sound/core/rawmidi.c:1576
 snd_rawmidi_write+0x2dc/0xc60 sound/core/rawmidi.c:1629
 vfs_write+0x2aa/0x1050 fs/read_write.c:685
 ksys_write+0x1f8/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fedf239de59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fedf31dd028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fedf2625fa0 RCX: 00007fedf239de59
RDX: 000000100000a3d9 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007fedf2433e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fedf2626038 R14: 00007fedf2625fa0 R15: 00007ffcea473a68
 </TASK>
----------------
Code disassembly (best guess):
   0:	f6 e8                	imul   %al
   2:	5d                   	pop    %rbp
   3:	00 48 89             	add    %cl,-0x77(%rax)
   6:	df 5b e9             	fistps -0x17(%rbx)
   9:	7d 63                	jge    0x6e
   b:	63 00                	movsxd (%rax),%eax
   d:	be 03 00 00 00       	mov    $0x3,%esi
  12:	5b                   	pop    %rbx
  13:	e9 52 af 11 03       	jmp    0x311af6a
  18:	66 90                	xchg   %ax,%ax
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	90                   	nop
  1f:	90                   	nop
  20:	90                   	nop
  21:	90                   	nop
  22:	90                   	nop
  23:	90                   	nop
  24:	90                   	nop
  25:	90                   	nop
  26:	90                   	nop
  27:	90                   	nop
  28:	90                   	nop
  29:	90                   	nop
* 2a:	f3 0f 1e fa          	endbr64 <-- trapping instruction
  2e:	65 8b 05 65 c7 59 12 	mov    %gs:0x1259c765(%rip),%eax        # 0x1259c79a
  35:	48 8b 34 24          	mov    (%rsp),%rsi
  39:	65                   	gs
  3a:	48                   	rex.W
  3b:	8b                   	.byte 0x8b
  3c:	15                   	.byte 0x15
  3d:	41 c7                	rex.B (bad)
  3f:	59                   	pop    %rcx

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/14 19:26 upstream 3b029c035b34 2130f682 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in update_rq_clock
2026/06/29 00:32 upstream 8b69c0475871 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in update_rq_clock
* Struck through repros no longer work on HEAD.