syzbot
upstream test error: WARNING in rcu_tasks_verify_work_fn
Status:
upstream: reported on 2026/09/15 00:01
Subsystems:
kernel
Labels:
prio:low
[Documentation on labels]
Reported-by: syzbot+9d7ab3bc11055d9740f5@syzkaller.appspotmail.com
First crash: 29d, last: 5d00h
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Last patch testing requests (1)
Sample crash report:
Callback from call_rcu_tasks_trace() invoked.
ACPI: \_SB_.LNKC: Enabled at IRQ 11
virtio-pci 0000:00:03.0: virtio_pci: leaving for legacy driver
ACPI: \_SB_.LNKD: Enabled at IRQ 10
virtio-pci 0000:00:04.0: virtio_pci: leaving for legacy driver
ACPI: \_SB_.LNKB: Enabled at IRQ 10
virtio-pci 0000:00:06.0: virtio_pci: leaving for legacy driver
virtio-pci 0000:00:07.0: virtio_pci: leaving for legacy driver
call_rcu_tasks() has failed boot-time tests.
rcu_tasks: RTGS_WAIT_SCAN_HOLDOUTS(6) since 56 g:5 i:0 kCuUP l:25
------------[ cut here ]------------
ret < 0
WARNING: kernel/rcu/tasks.h:1541 at rcu_tasks_verify_self_tests kernel/rcu/tasks.h:1541 [inline], CPU#0: kworker/0:1/10
WARNING: kernel/rcu/tasks.h:1541 at rcu_tasks_verify_work_fn+0x1b6/0x270 kernel/rcu/tasks.h:1553, CPU#0: kworker/0:1/10
Modules linked in:
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: events rcu_tasks_verify_work_fn
RIP: 0010:rcu_tasks_verify_self_tests kernel/rcu/tasks.h:1541 [inline]
RIP: 0010:rcu_tasks_verify_work_fn+0x1b6/0x270 kernel/rcu/tasks.h:1553
Code: 80 3c 10 00 0f 85 b5 00 00 00 48 8b 35 db 64 77 0c b9 64 00 00 00 bf 08 00 00 00 48 c7 c2 a0 6a 9a 9b e8 6d 5a e2 ff eb 97 90 <0f> 0b 90 eb 91 48 89 df e8 fd c9 8f 00 e9 69 ff ff ff 48 89 df e8
RSP: 0000:ffffc900000f7bb0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffffffff8edeba28 RCX: 0000000000000000
RDX: 1ffffffff1dbd745 RSI: ffffffff81e9b0c9 RDI: fffff5200001ef49
RBP: 1ffff9200001ef76 R08: 0000000000000007 R09: 0000000000000000
R10: 8000000000000000 R11: 0000000000000001 R12: 0000000000000bb8
R13: 00000000ffffffff R14: 0000000000000001 R15: ffffffff8edeba28
FS: 0000000000000000(0000) GS:ffff888123b52000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88823ffff000 CR3: 000000000eb96000 CR4: 00000000003526f0
Call Trace:
<TASK>
process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
process_scheduled_works kernel/workqueue.c:3479 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560
kthread+0x373/0x450 kernel/kthread.c:436
ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Struck through repros no longer work on HEAD.