syzbot


INFO: task hung in pwq_release_workfn

Status: auto-obsoleted due to no activity on 2025/08/15 06:35
Subsystems: net
[Documentation on labels]
First crash: 101d, last: 101d

Sample crash report:
INFO: task pool_workqueue_:3 blocked for more than 143 seconds.
      Not tainted 6.15.0-rc6-syzkaller-ga82e92598ab1 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:pool_workqueue_ state:D stack:0     pid:3     tgid:3     ppid:2      task_flags:0x208040 flags:0x00000010
Call trace:
 __switch_to+0x414/0x834 arch/arm64/kernel/process.c:735 (T)
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x13b0/0x28d4 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0xb4/0x230 kernel/sched/core.c:6860
 schedule_preempt_disabled+0x18/0x2c kernel/sched/core.c:6917
 __mutex_lock_common+0xbd0/0x2190 kernel/locking/mutex.c:678
 __mutex_lock kernel/locking/mutex.c:746 [inline]
 mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:798
 pwq_release_workfn+0x37c/0x6e4 kernel/workqueue.c:5091
 kthread_worker_fn+0x43c/0xb34 kernel/kthread.c:1010
 kthread+0x5fc/0x75c kernel/kthread.c:464
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847

Showing all locks held in the system:
1 lock held by kthreadd/2:
1 lock held by pool_workqueue_/3:
 #0: ffff80008f3b0d48 (wq_pool_mutex){+.+.}-{4:4}, at: pwq_release_workfn+0x37c/0x6e4 kernel/workqueue.c:5091
1 lock held by kworker/R-kvfre/6:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2736 [inline]
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x86c/0xec8 kernel/workqueue.c:3529
3 locks held by kworker/0:0/9:
3 locks held by kworker/u8:0/12:
1 lock held by kworker/R-mm_pe/13:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x40/0x348 kernel/workqueue.c:2678
3 locks held by kworker/u8:1/14:
1 lock held by khungtaskd/32:
 #0: ffff80008f5088a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x48 include/linux/rcupdate.h:330
3 locks held by kworker/u8:2/44:
4 locks held by kworker/u8:3/45:
 #0: ffff0000c0031948 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x658/0x156c kernel/workqueue.c:3212
 #1: ffff800097d67bc0 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x6ec/0x156c kernel/workqueue.c:3212
 #2: ffff80009248b428 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
 #3: ffff000104178768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6092 [inline]
 #3: ffff000104178768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_leave_invalid_chans net/wireless/reg.c:2471 [inline]
 #3: ffff000104178768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_check_chans_work+0x11c/0xd88 net/wireless/reg.c:2486
2 locks held by pr/ttyAMA0/46:
3 locks held by kworker/u8:4/59:
2 locks held by kworker/u8:5/218:
3 locks held by kworker/u8:6/342:
3 locks held by kworker/u8:7/652:
3 locks held by kworker/u8:8/710:
4 locks held by kworker/u8:9/781:
 #0: ffff0000efe30148 ((wq_completion)wg-kex-wg1#5){+.+.}-{0:0}, at: process_one_work+0x658/0x156c kernel/workqueue.c:3212
 #1: ffff80009d487bc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x6ec/0x156c kernel/workqueue.c:3212
 #2: ffff0000efd4d308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x10c/0x6c8 drivers/net/wireguard/noise.c:529
 #3: ffff0000cd949708 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x114/0x6c8 drivers/net/wireguard/noise.c:530
3 locks held by kworker/u8:10/2211:
1 lock held by kworker/R-dm_bu/3411:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x40/0x348 kernel/workqueue.c:2678
3 locks held by kworker/R-ipv6_/4141:
 #0: ffff0000d2955148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x658/0x156c kernel/workqueue.c:3212
 #1: ffff8000a3277ba0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x6ec/0x156c kernel/workqueue.c:3212
 #2: ffff80009248b428 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock+0x20/0x2c net/core/rtnetlink.c:80
2 locks held by kworker/R-bat_e/4222:
1 lock held by klogd/6094:
1 lock held by udevd/6105:
2 locks held by getty/6256:
 #0: ffff0000d308d0a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
 #1: ffff80009b60b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x34c/0xfa0 drivers/tty/n_tty.c:2222
2 locks held by kworker/0:2/6480:
2 locks held by syz-executor/6489:
1 lock held by kworker/R-wg-cr/6520:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x40/0x348 kernel/workqueue.c:2678
1 lock held by kworker/R-wg-cr/6528:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x40/0x348 kernel/workqueue.c:2678
1 lock held by kworker/R-wg-cr/6529:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2736 [inline]
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x86c/0xec8 kernel/workqueue.c:3529
1 lock held by kworker/R-wg-cr/6533:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x40/0x348 kernel/workqueue.c:2678
1 lock held by kworker/R-wg-cr/6535:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x40/0x348 kernel/workqueue.c:2678
1 lock held by kworker/R-wg-cr/6536:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x40/0x348 kernel/workqueue.c:2678
3 locks held by kworker/0:3/6570:
3 locks held by kworker/1:9/6582:
1 lock held by udevd/6605:
2 locks held by kworker/0:4/6643:
3 locks held by kworker/u8:11/6666:
1 lock held by kworker/R-wg-cr/7071:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2736 [inline]
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x86c/0xec8 kernel/workqueue.c:3529
1 lock held by kworker/R-wg-cr/7075:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x40/0x348 kernel/workqueue.c:2678
1 lock held by kworker/R-wg-cr/7080:
 #0: ffff80008f3b0ee8 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x40/0x348 kernel/workqueue.c:2678
1 lock held by kworker/R-wg-cr/7902:
2 locks held by syz.6.314/8387:
 #0: ffff0000c6b220e0 (&type->s_umount_key#57/1){+.+.}-{4:4}, at: alloc_super+0x1a0/0x80c fs/super.c:344
 #1: ffff80008f3b0d48 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5179 [inline]
 #1: ffff80008f3b0d48 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0x7b4/0x16d8 kernel/workqueue.c:5734
2 locks held by syz.5.313/8394:
3 locks held by syz.3.323/8419:
3 locks held by sed/8430:
3 locks held by kworker/u8:12/8438:
2 locks held by kworker/0:5/8440:
3 locks held by syz-executor/8443:

=============================================


Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/05/17 06:28 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a82e92598ab1 f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in pwq_release_workfn
* Struck through repros no longer work on HEAD.