syzbot


INFO: task hung in worker_attach_to_pool (3)

Status: upstream: reported C repro on 2025/08/29 21:46
Subsystems: kernel
[Documentation on labels]
Reported-by: syzbot+a50479d6d26ffd27e13b@syzkaller.appspotmail.com
First crash: 4d14h, last: 4d14h
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [kernel?] INFO: task hung in worker_attach_to_pool (3) 0 (1) 2025/08/29 21:46
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in worker_attach_to_pool tipc 1 6 1743d 1748d 0/29 auto-closed as invalid on 2021/01/19 23:38
upstream INFO: task hung in worker_attach_to_pool (2) kernel 1 47 224d 324d 0/29 auto-obsoleted due to no activity on 2025/03/30 19:41

Sample crash report:
INFO: task kworker/1:0:24 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0     state:D stack:26792 pid:24    tgid:24    ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue:  0x0 (mld)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x81b/0x1060 kernel/locking/mutex.c:760
 worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2676
 create_worker+0x2a9/0x7e0 kernel/workqueue.c:2818
 maybe_create_worker kernel/workqueue.c:3061 [inline]
 manage_workers kernel/workqueue.c:3113 [inline]
 worker_thread+0x9dd/0xf10 kernel/workqueue.c:3375
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task kworker/0:7:6151 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:7     state:D stack:31320 pid:6151  tgid:6151  ppid:2      task_flags:0x4208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 kthread+0x236/0x780 kernel/kthread.c:451
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
INFO: task kworker/1:7:6152 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:7     state:D stack:31320 pid:6152  tgid:6152  ppid:2      task_flags:0x4208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/25 21:37 upstream 1b237f190eb3 bf27483f .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in worker_attach_to_pool
* Struck through repros no longer work on HEAD.