syzbot

 sign-in | mailing list | source | docs | 🏰
🐞 Open [1348]
≡ Subsystems
🐞 Fixed [7125]
🐞 Invalid [18852]
⬇ Missing Backports [220]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
✨ AI
💬 Send us feedback

INFO: task hung in worker_attach_to_pool (3)

Status: upstream: reported C repro on 2025/08/29 21:46
Subsystems: kernel
Labels: prio:normal
[Documentation on labels]
Reported-by: syzbot+a50479d6d26ffd27e13b@syzkaller.appspotmail.com
First crash: 279d, last: 3d12h
Cause bisection: failed (error log, bisect log)
  
Fix bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
4d13d823-7162-48bf-bdd1-73a653b86f22 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: task hung in worker_attach_to_pool (3) 2026/05/13 02:47 2026/05/13 02:47 2026/05/13 04:07 ac1aeadbb84e4988133fcdf26ca80803a538fe09
▶ ▼ 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 2018d 2022d 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 499d 599d 0/29 auto-obsoleted due to no activity on 2025/03/30 19:41
▶ ▼ Last patch testing requests (3)
Created Duration User Patch Repo Result
2026/04/14 09:00 20m retest repro upstream report log
2026/03/24 02:15 26m retest repro upstream OK log
2025/09/09 01:48 39m retest repro upstream report log
▶ ▼ Fix bisection attempts (4)
Created Duration User Patch Repo Result
2026/02/03 08:41 17m bisect fix upstream error job log
2025/12/16 18:52 3h21m bisect fix upstream OK (0) job log log
2025/11/15 12:38 3h09m bisect fix upstream OK (0) job log log
2025/10/11 10:03 4h00m bisect fix upstream OK (0) job log log

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 (8):
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
2026/05/19 08:02 upstream 4d3a2a466b8d 9f74d399 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in worker_attach_to_pool
2026/05/08 08:43 upstream 917719c412c4 5633175a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in worker_attach_to_pool
2026/04/27 06:17 upstream 20b64cf8705a 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in worker_attach_to_pool
2026/03/10 00:08 upstream 1f318b96cc84 176bead5 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in worker_attach_to_pool
2026/02/20 15:58 upstream 8bf22c33e7a1 741f5161 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in worker_attach_to_pool
2026/01/04 04:58 upstream aacb0a6d604a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in worker_attach_to_pool
2026/05/28 13:51 net 031f1592e592 9a5a7e5e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: task hung in worker_attach_to_pool
* Struck through repros no longer work on HEAD.