syzbot


INFO: task hung in idle_cull_fn (3)

Status: auto-obsoleted due to no activity on 2026/02/07 21:13
Subsystems: kernel
[Documentation on labels]
First crash: 188d, last: 112d
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in idle_cull_fn (2) kernel 1 2 474d 514d 0/29 auto-obsoleted due to no activity on 2025/02/11 08:33
upstream INFO: task hung in idle_cull_fn kernel 1 2 638d 666d 0/29 auto-obsoleted due to no activity on 2024/08/30 14:38

Sample crash report:
INFO: task kworker/u8:4:59 blocked for more than 162 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4    state:D stack:24216 pid:59    tgid:59    ppid:2      task_flags:0x4208160 flags:0x00004000
Workqueue: events_unbound idle_cull_fn
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
 idle_cull_fn+0x99/0x460 kernel/workqueue.c:2958
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 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/R-wg-cr:5887 blocked for more than 163 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/R-wg-cr state:D stack:28552 pid:5887  tgid:5887  ppid:2      task_flags:0x4208060 flags:0x00004000
Workqueue:  0x0 (wg-crypt-wg0)
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

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/25 15:45 upstream 1b237f190eb3 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in idle_cull_fn
2025/11/09 21:10 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 18514fd70ea4 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: task hung in idle_cull_fn
* Struck through repros no longer work on HEAD.