WARNING in rcu_tasks_verify_work_fn

Status: upstream: reported on 2026/03/31 21:53
Subsystems: kernel
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+251e9abcdac140e7ec74@syzkaller.appspotmail.com
First crash: 128d, last: 12h16m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
f65ca737 assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in rcu_tasks_verify_work_fn 2026/05/26 01:24 2026/05/26 01:24 2026/05/26 01:51 c69befb3

			
		
Discussions (3)
Title Replies (including bot) Last reply
[PATCH] rcu-tasks: Dump rcu tasks status when the boot-test failed 1 (1) 2026/07/06 10:03
[PATCH] rcu-tasks: Fix possible boot-time tests failed for the call_rcu_tasks() 1 (1) 2026/04/23 11:19
[syzbot] [kernel?] WARNING in rcu_tasks_verify_work_fn 0 (1) 2026/03/31 21:53

Sample crash report:
input: AT Translated Set 2 keyboard as /devices/platform/i8042/serio0/input/input2
input: ImExPS/2 Generic Explorer Mouse as /devices/platform/i8042/serio1/input/input4
call_rcu_tasks() has failed boot-time tests.
------------[ cut here ]------------
ret < 0
WARNING: kernel/rcu/tasks.h:1531 at rcu_tasks_verify_self_tests kernel/rcu/tasks.h:1531 [inline], CPU#1: kworker/1:1/29
WARNING: kernel/rcu/tasks.h:1531 at rcu_tasks_verify_work_fn+0x27c/0x360 kernel/rcu/tasks.h:1543, CPU#1: kworker/1:1/29
Modules linked in:
CPU: 1 UID: 0 PID: 29 Comm: kworker/1:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events rcu_tasks_verify_work_fn
RIP: 0010:rcu_tasks_verify_self_tests kernel/rcu/tasks.h:1531 [inline]
RIP: 0010:rcu_tasks_verify_work_fn+0x27c/0x360 kernel/rcu/tasks.h:1543
Code: 8e ba ff ff 37 00 48 c1 e8 03 48 c1 e2 2a 0f b6 04 10 84 c0 74 06 0f 8e d7 00 00 00 80 3d bb b8 d1 0c 00 0f 85 f3 fe ff ff 90 <0f> 0b 90 e9 39 fe ff ff 48 c7 c7 80 f2 80 8e e8 40 80 8c 00 e9 21
RSP: 0000:ffffc90000a47be0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 1ffff92000148f7c RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff81e816a9 RDI: fffff52000148f6d
RBP: 0000000000000bb8 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: ffffffff8e80f280
R13: ffffffffffffffed R14: ffffffff9122e384 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888123edf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000000e994000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (24):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/03 07:26 upstream bd1dde877520 e611ffe1 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/28 16:56 upstream 62cc90241548 4a865b71 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/27 11:52 upstream f5098b6bae76 4a865b71 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/25 05:08 upstream 48a5a7ab8d6a 4a865b71 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/24 19:20 upstream 48a5a7ab8d6a 4a865b71 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/21 17:14 upstream b95f03f04d47 7c5de9c3 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/12 09:07 upstream 44696aa3a489 d78ea535 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/12 09:06 upstream 44696aa3a489 d78ea535 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/11 04:26 upstream 61c03dfde854 d78ea535 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/05 20:38 upstream f105f3631d51 fcece630 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/05 02:39 upstream 1e9cdc2ea15a fcece630 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/03 06:49 upstream 87320be9f0d2 58bf2096 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/03 03:36 upstream 87320be9f0d2 58bf2096 .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/07/01 09:29 upstream 665159e24674 00a5cf1c .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/06/28 23:18 upstream 8b69c0475871 fb92f11c .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/06/27 18:01 upstream 5a66900afbd6 fb92f11c .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/06/26 14:46 upstream 4edcdefd4083 fb92f11c .config console log report [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto WARNING in rcu_tasks_verify_work_fn
2026/06/25 12:48 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 319fafd9a374 432fd51a .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in rcu_tasks_verify_work_fn
2026/05/28 22:21 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 0ca1724b56af 9a5a7e5e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in rcu_tasks_verify_work_fn
2026/04/27 05:43 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 9c2d0995 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in rcu_tasks_verify_work_fn
2026/04/23 12:00 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next 9b3a2be84803 b10da5ec .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in rcu_tasks_verify_work_fn
2026/03/27 22:12 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next b335bc5892a0 158c21af .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in rcu_tasks_verify_work_fn
2026/03/27 21:42 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next b335bc5892a0 158c21af .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in rcu_tasks_verify_work_fn
2026/03/27 21:42 git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux.git for-next b335bc5892a0 158c21af .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu2-riscv64 WARNING in rcu_tasks_verify_work_fn
* Struck through repros no longer work on HEAD.