syzbot


INFO: task hung in worker_thread (2)

Status: auto-closed as invalid on 2021/05/17 11:26
Subsystems: fs
[Documentation on labels]
First crash: 1184d, last: 1184d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in worker_thread 1 832d 832d 0/1 auto-closed as invalid on 2022/05/08 06:12
upstream INFO: task hung in worker_thread (3) serial 1 424d 424d 0/26 auto-obsoleted due to no activity on 2023/05/20 16:01
upstream INFO: task hung in worker_thread (4) kernel 1 109d 109d 0/26 auto-obsoleted due to no activity on 2024/03/31 02:07
upstream INFO: task hung in worker_thread fs 1 1350d 1350d 0/26 auto-closed as invalid on 2020/11/06 03:23

Sample crash report:
INFO: task kworker/0:27:15748 blocked for more than 143 seconds.
      Not tainted 5.11.0-rc3-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:27    state:I stack:25744 pid:15748 ppid:     2 flags:0x00004000
Workqueue:  0x0 (events)
Call Trace:
 context_switch kernel/sched/core.c:4313 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5064
 schedule+0xcf/0x270 kernel/sched/core.c:5143
 worker_thread+0x14c/0x1120 kernel/workqueue.c:2442
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Showing all locks held in the system:
3 locks held by kworker/u4:3/120:
1 lock held by khungtaskd/1656:
 #0: ffffffff8b373920 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254
2 locks held by systemd-journal/4885:
1 lock held by in:imklog/8163:
 #0: ffff8880202beff0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947
4 locks held by kworker/u4:15/10084:
 #0: ffff8881407a3138 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff8881407a3138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff8881407a3138 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff8881407a3138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff8881407a3138 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff8881407a3138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246
 #1: ffffc9001691fda8 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250
 #2: ffffffff8ca45390 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xb10 net/core/net_namespace.c:566
 #3: ffffffff8ca587e8 (rtnl_mutex){+.+.}-{3:3}, at: tc_action_net_exit include/net/act_api.h:147 [inline]
 #3: ffffffff8ca587e8 (rtnl_mutex){+.+.}-{3:3}, at: gate_exit_net+0x22/0x360 net/sched/act_gate.c:624
2 locks held by kworker/0:27/15748:
2 locks held by kworker/1:5/12270:
 #0: ffff88801007c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff88801007c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:856 [inline]
 #0: ffff88801007c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:41 [inline]
 #0: ffff88801007c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:616 [inline]
 #0: ffff88801007c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:643 [inline]
 #0: ffff88801007c538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x871/0x15f0 kernel/workqueue.c:2246
 #1: ffffc90016e0fda8 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x15f0 kernel/workqueue.c:2250
4 locks held by syz-executor.1/23529:
 #0: ffff888057834f48 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close+0x111/0x1110 net/bluetooth/hci_core.c:1726
 #1: ffff888057834078 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_do_close+0x26f/0x1110 net/bluetooth/hci_core.c:1763
 #2: ffffffff8cc5f5c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:1459 [inline]
 #2: ffffffff8cc5f5c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xda/0x260 net/bluetooth/hci_conn.c:1565
 #3: ffffffff8b37c1e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #3: ffffffff8b37c1e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f2/0x610 kernel/rcu/tree_exp.h:836
2 locks held by syz-executor.3/23525:
 #0: ffffffff8ca587e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:676 [inline]
 #0: ffffffff8ca587e8 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x3a/0x180 drivers/net/tun.c:3354
 #1: ffffffff8b37c1e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
 #1: ffffffff8b37c1e8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x27e/0x610 kernel/rcu/tree_exp.h:836

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

NMI backtrace for cpu 1
CPU: 1 PID: 1656 Comm: khungtaskd Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd43/0xfa0 kernel/hung_task.c:294
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 120 Comm: kworker/u4:3 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:__lock_acquire+0xda5/0x54f0 kernel/locking/lockdep.c:4702
Code: d3 33 0d e9 83 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 80 3c 02 00 0f 85 0c 30 00 00 49 81 3e c0 a2 61 8e <0f> 84 39 f3 ff ff 41 83 fc 01 0f 87 3b f3 ff ff 44 89 e0 0f 87 53
RSP: 0000:ffffc900012cf9e0 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: 1ffff1100b78c973 RSI: 0000000000000000 RDI: ffff88805bc64b98
RBP: ffff8880114c8000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88805bc64b98 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7cc6aff000 CR3: 0000000015397000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_acquire kernel/locking/lockdep.c:5437 [inline]
 lock_acquire+0x29d/0x740 kernel/locking/lockdep.c:5402
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:359 [inline]
 batadv_nc_purge_paths+0xdf/0x3a0 net/batman-adv/network-coding.c:438
 batadv_nc_worker+0x831/0xe50 net/batman-adv/network-coding.c:716
 process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/01/20 15:41 net-old 9c30ae8398b0 d4f4eca5 .config console log report info ci-upstream-net-this-kasan-gce INFO: task hung in worker_thread
* Struck through repros no longer work on HEAD.