syzbot
WARNING in update_rq_clock
Status:
upstream: reported C repro on 2026/08/18 22:00
Reported-by: syzbot+1448aa2d40dcd6cfe9d8@syzkaller.appspotmail.com
First crash: 2d00h, last: 2d00h
Sample crash report:
x86: Booting SMP configuration:
smpboot: Booting Node 0 Processor 1 APIC 0x1
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4438 at kernel/sched/sched.h:1353 update_rq_clock+0x305/0x440 kernel/sched/core.c:750
Modules linked in:
CPU: 0 PID: 4438 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:lockdep_assert_rq_held kernel/sched/sched.h:1353 [inline]
RIP: 0010:update_rq_clock+0x305/0x440 kernel/sched/core.c:734
Code: 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 ed 8c 7a 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 48 83 c4 08 5b 41 5c 41 5d 41 5e 41
RSP: 0018:ffffc90003317740 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffff8880b8f3ad00 RCX: 5f220f5c89853900
RDX: 0000000000000000 RSI: ffffffff8a8c2920 RDI: ffffffff8adf5de0
RBP: ffffc90003317910 R08: ffff888020391c27 R09: ffff888020391c01
R10: dffffc0000000000 R11: ffffed1004072385 R12: ffff8880b8f3ad00
R13: dffffc0000000000 R14: ffff8880b8f3ba48 R15: ffff888019ed3c01
FS: 000055555ab15500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe9497b000 CR3: 000000002e234000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
pick_next_task kernel/sched/core.c:6052 [inline]
__schedule+0x2691/0x4030 kernel/sched/core.c:6526
schedule+0xb9/0x180 kernel/sched/core.c:6639
do_boot_cpu arch/x86/kernel/smpboot.c:1189 [inline]
native_cpu_up+0xf45/0x1820 arch/x86/kernel/smpboot.c:1247
__cpu_up arch/x86/include/asm/smp.h:84 [inline]
bringup_cpu+0x5b/0x340 kernel/cpu.c:630
cpuhp_invoke_callback+0x423/0x7e0 kernel/cpu.c:192
__cpuhp_invoke_callback_range kernel/cpu.c:700 [inline]
cpuhp_invoke_callback_range kernel/cpu.c:724 [inline]
cpuhp_up_callbacks kernel/cpu.c:755 [inline]
_cpu_up+0x4d7/0x8f0 kernel/cpu.c:1458
cpu_up+0x1ea/0x270 kernel/cpu.c:1494
cpu_subsys_online+0x60/0x140 drivers/base/cpu.c:58
device_online drivers/base/core.c:4260 [inline]
online_store+0x222/0x310 drivers/base/core.c:2725
kernfs_fop_write_iter+0x3a0/0x520 fs/kernfs/file.c:352
call_write_iter include/linux/fs.h:2265 [inline]
new_sync_write fs/read_write.c:491 [inline]
vfs_write+0x482/0x9a0 fs/read_write.c:584
ksys_write+0x14d/0x260 fs/read_write.c:637
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f615039e0d9
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:00007ffee5a10878 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6150625fa0 RCX: 00007f615039e0d9
RDX: 0000000000000009 RSI: 0000200000000080 RDI: 0000000000000003
RBP: 00007f6150435024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6150625fac R14: 00007f6150625fa0 R15: 00007f6150625fa0
</TASK>
* Struck through repros no longer work on HEAD.