linux-kernel - [syzbot] [kernel?] INFO: task hung in worker_attach_to

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Message-ID: <68b21fbc.a70a0220.f8cc2.00fd.GAE@google.com>
Date: Fri, 29 Aug 2025 14:46:36 -0700
From: syzbot <syzbot+a50479d6d26ffd27e13b@...kaller.appspotmail.com>
To: bp@...en8.de, dave.hansen@...ux.intel.com, hpa@...or.com, 
	linux-kernel@...r.kernel.org, mingo@...hat.com, 
	syzkaller-bugs@...glegroups.com, tglx@...utronix.de, x86@...nel.org
Subject: [syzbot] [kernel?] INFO: task hung in worker_attach_to_pool (3)

Hello,

syzbot found the following issue on:

HEAD commit:    1b237f190eb3 Linux 6.17-rc3
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10a96ef0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d4703ac89d9e185a
dashboard link: https://syzkaller.appspot.com/bug?extid=a50479d6d26ffd27e13b
compiler:       gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12397862580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10b11c42580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9d469fb7e3a4/disk-1b237f19.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/4114df4f6a8b/vmlinux-1b237f19.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fa16b8bb6a18/bzImage-1b237f19.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+a50479d6d26ffd27e13b@...kaller.appspotmail.com

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


---
This report is generated by a bot. It may contain errors.
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