syzbot


INFO: task hung in worker_thread (6)

Status: upstream: reported C repro on 2026/02/02 18:05
Subsystems: hfs
[Documentation on labels]
Reported-by: syzbot+fa1cc3e4b001b79309ec@syzkaller.appspotmail.com
First crash: 6d03h, last: 6d03h
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [hfs?] INFO: task hung in worker_thread (6) 0 (1) 2026/02/02 18:05
Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in worker_thread 1 1 1489d 1489d 0/1 auto-closed as invalid on 2022/05/08 06:12
upstream INFO: task hung in worker_thread (3) serial 1 1 1081d 1081d 0/29 auto-obsoleted due to no activity on 2023/05/20 16:01
upstream INFO: task hung in worker_thread (5) kernel 1 C done done 49 146d 493d 0/29 auto-obsoleted due to no activity on 2025/12/21 10:04
upstream INFO: task hung in worker_thread (4) kernel 1 1 766d 766d 0/29 auto-obsoleted due to no activity on 2024/03/31 02:07
android-6-12 INFO: task hung in worker_thread 1 2 208d 216d 0/1 auto-obsoleted due to no activity on 2025/10/10 04:19
upstream INFO: task hung in worker_thread (2) fs 1 1 1841d 1841d 0/29 auto-closed as invalid on 2021/05/17 11:26
linux-5.15 INFO: task hung in worker_thread 1 1 457d 457d 0/3 auto-obsoleted due to no activity on 2025/02/12 21:25
android-6-12 INFO: task hung in worker_thread (2) 1 1 103d 103d 0/1 auto-obsoleted due to no activity on 2026/01/23 01:25
upstream INFO: task hung in worker_thread fs 1 1 2007d 2007d 0/29 auto-closed as invalid on 2020/11/06 03:23

Sample crash report:
INFO: task kworker/u8:5:78 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5    state:D stack:23136 pid:78    tgid:78    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x1539/0x5080 kernel/sched/core.c:6907
 process_scheduled_works kernel/workqueue.c:3362 [inline]
 worker_thread+0xb46/0x1140 kernel/workqueue.c:3443
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
1 lock held by khungtaskd/30:
 #0: 
ffffffff8e7601a0
 (
){....}-{1:3}
ffff8880206a0148
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
, at: hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28
4 locks held by kworker/u8:3/49:
 #0: 
ffff8880206a0148
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
 #1: 
ffffc90000ba7c40
 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
 #2: ffff88802b4f00e0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
 #3: ffff88802b4f20b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28
4 locks held by kworker/u8:5/78:
 #0: ffff8880206a0148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
 #1: ffffc900025cfc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
 #2: ffff8880348a80e0 (&type->s_umount_key#55){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
 #3: ffff8880361ee0b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28
4 locks held by kworker/u8:6/1143:
 #0: ffff8880206a0148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/30 11:43 linux-next 33a647c659ff bfa73b7b .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-linux-next-kasan-gce-root INFO: task hung in worker_thread
* Struck through repros no longer work on HEAD.