WARNING in update_rq_clock

Status: upstream: reported C repro on 2026/10/16 08:29
Reported-by: syzbot+bd3c0b70977d400ea662@syzkaller.appspotmail.com
First crash: 1d23h, last: 1d23h
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in update_rq_clock fs -1 23 225d 316d 0/29 auto-obsoleted due to no activity on 2026/05/15 14:56
linux-6.1 WARNING in update_rq_clock -1 syz, C 1 25d 60d 0/3 upstream: reported C repro on 2026/08/18 22:00
upstream WARNING in update_rq_clock (2) prio:low kernel -1 syz, C error 1568 7h52m 107d 0/29 upstream: reported C repro on 2026/07/03 00:38

Sample crash report:
x86: Booting SMP configuration:
smpboot: Booting Node 0 Processor 1 APIC 0x1
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4393 at kernel/sched/sched.h:1317 update_rq_clock+0x305/0x460 kernel/sched/core.c:687
Modules linked in:
CPU: 0 PID: 4393 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1317 [inline]
RIP: 0010:update_rq_clock+0x305/0x460 kernel/sched/core.c:671
Code: 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 fd fe 6b 00 48 01 2b 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3 <0f> 0b e9 87 fd ff ff 48 89 df e8 4c c4 01 00 49 89 c6 48 81 c3 88
RSP: 0018:ffffc900032bf6c0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8880b8f3a340 RCX: 15086e6baa677f00
RDX: 0000000000000000 RSI: ffffffff8a2b3e00 RDI: ffffffff8a7a4b40
RBP: ffffc900032bf8e0 R08: ffff8880b8e3a49c R09: ffff88802c445c01
R10: dffffc0000000000 R11: ffffed1005888b85 R12: 0000000000000001
R13: dffffc0000000000 R14: ffff8880b8f3b088 R15: ffff8880b8f00000
FS:  0000555571334500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f128eb9b6f1 CR3: 0000000072eec000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 pick_next_task kernel/sched/core.c:5870 [inline]
 __schedule+0x26d9/0x4350 kernel/sched/core.c:6359
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 do_boot_cpu arch/x86/kernel/smpboot.c:1134 [inline]
 native_cpu_up+0xdd9/0x15e0 arch/x86/kernel/smpboot.c:1192
 __cpu_up arch/x86/include/asm/smp.h:87 [inline]
 bringup_cpu+0x5b/0x290 kernel/cpu.c:607
 cpuhp_invoke_callback+0x423/0x7e0 kernel/cpu.c:191
 __cpuhp_invoke_callback_range kernel/cpu.c:677 [inline]
 cpuhp_invoke_callback_range kernel/cpu.c:701 [inline]
 cpuhp_up_callbacks kernel/cpu.c:732 [inline]
 _cpu_up+0x471/0x810 kernel/cpu.c:1400
 cpu_up+0x16d/0x1a0 kernel/cpu.c:1436
 cpu_subsys_online+0x60/0x140 drivers/base/cpu.c:58
 device_online drivers/base/core.c:3977 [inline]
 online_store+0x222/0x310 drivers/base/core.c:2464
 kernfs_fop_write_iter+0x3a8/0x500 fs/kernfs/file.c:296
 call_write_iter include/linux/fs.h:2179 [inline]
 new_sync_write fs/read_write.c:507 [inline]
 vfs_write+0x748/0xd70 fs/read_write.c:594
 ksys_write+0x153/0x260 fs/read_write.c:647
 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: 0033:0x7f3617a9f559
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:00007fffafa1bc38 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f3617d26fa0 RCX: 00007f3617a9f559
RDX: 0000000000000002 RSI: 00002000000001c0 RDI: 0000000000000003
RBP: 00007f3617b368b0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3617d26fac R14: 00007f3617d26fa0 R15: 00007f3617d26fa0
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/16 08:28 linux-5.15.y 792fbe1537d8 3f2522c6 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in update_rq_clock
* Struck through repros no longer work on HEAD.