INFO: task kworker/u4:3:3286 blocked for more than 140 seconds.
      Not tainted 4.14.94+ #10
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:3    D25920  3286      2 0x80000000
Workqueue: netns cleanup_net
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3490
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893
 cleanup_net+0x136/0x860 net/core/net_namespace.c:449
 process_one_work+0x7c6/0x14e0 kernel/workqueue.c:2114
 worker_thread+0x5d7/0x1080 kernel/workqueue.c:2248
 kthread+0x310/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff947ffc0c>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
2 locks held by getty/1755:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffff95336a02>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffff95331e27>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
1 lock held by syz-executor5/1813:
 #0:  (&rq->lock){-.-.}, at: [<ffffffff95e3f1a7>] rq_lock kernel/sched/sched.h:1835 [inline]
 #0:  (&rq->lock){-.-.}, at: [<ffffffff95e3f1a7>] __schedule+0x197/0x1f30 kernel/sched/core.c:3376
3 locks held by kworker/u4:3/3286:
 #0:  ("%s""netns"){+.+.}, at: [<ffffffff94727dc5>] process_one_work+0x6e5/0x14e0 kernel/workqueue.c:2085
 #1:  (net_cleanup_work){+.+.}, at: [<ffffffff94727dfb>] process_one_work+0x71b/0x14e0 kernel/workqueue.c:2089
 #2:  (net_mutex){+.+.}, at: [<ffffffff958eb5d6>] cleanup_net+0x136/0x860 net/core/net_namespace.c:449
2 locks held by kworker/u4:4/31261:
 #0:  ("events_unbound"){+.+.}, at: [<ffffffff94727dc5>] process_one_work+0x6e5/0x14e0 kernel/workqueue.c:2085
 #1:  ((&sub_info->work)){+.+.}, at: [<ffffffff94727dfb>] process_one_work+0x71b/0x14e0 kernel/workqueue.c:2089
1 lock held by syz-executor3/25983:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/25995:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/26043:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/26068:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/26081:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/26133:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/26153:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/26163:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/26167:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/26203:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/26244:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/26256:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/26263:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/26293:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/26321:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/26328:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor3/26329:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/26345:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor3/26402:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/26448:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor3/26509:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/26518:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/26621:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/26733:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/26750:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/26795:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/26829:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/26837:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/26883:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/26946:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/26950:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/26986:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/27012:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/27047:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/27071:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/27186:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/27290:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/27301:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/27381:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/27609:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/27687:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/27762:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/27850:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/27895:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/27922:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/27933:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/27960:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/27987:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/28006:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/28032:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/28141:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/28178:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/28243:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/28393:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/28419:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/28451:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/28674:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/28849:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/28895:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/28956:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/29172:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/29259:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/29306:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/29552:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/16632:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/17250:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/17404:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/17475:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/17496:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor4/17545:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/17593:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/17880:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/17922:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/17946:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/17992:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/18100:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/18105:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/18109:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor5/18149:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/18161:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/18189:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/18214:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/18236:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/18437:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/18484:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/18689:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/18811:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/18870:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor0/18894:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/18939:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/18978:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor2/20225:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor3/20229:
 #0:  (net_mutex){+.+.}, at: [<ffffffff958ec206>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:409
1 lock held by syz-executor1/20249:
 #0:  (&sig->cred_guard_mutex){+.+.}, at: [<ffffffff94b6c3a1>] prepare_bprm_creds+0x51/0x110 fs/exec.c:1389
1 lock held by syz-executor3/20256:
 #0:  (&mm->mmap_sem){++++}, at: [<ffffffff946b4a61>] __do_page_fault+0x871/0xb80 arch/x86/mm/fault.c:1361
1 lock held by syz-executor2/20257:
 #0:  (&mm->mmap_sem){++++}, at: [<ffffffff946b4a61>] __do_page_fault+0x871/0xb80 arch/x86/mm/fault.c:1361

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

NMI backtrace for cpu 0
CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.94+ #10
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 1830 Comm: syz-executor4 Not tainted 4.14.94+ #10
task: ffff8881d4750000 task.stack: ffff8881ac8e0000
RIP: 0010:wait_consider_task+0x2b1/0x3110 kernel/exit.c:1362
RSP: 0018:ffff8881ac8e7ad8 EFLAGS: 00000a06
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8881ca1de284
RDX: 1ffff1103943bbc5 RSI: 0000000000000000 RDI: ffff8881ac8e7cd8
RBP: 0000000000000000 R08: 00000000000043a2 R09: 000000000006007d
R10: ffff8881d4750830 R11: 0000000000000001 R12: ffff8881ac8e7cdc
R13: ffff8881ca1dde28 R14: ffff8881ac8e7cd8 R15: ffff8881ca1dde00
FS:  000000000148c940(0000) GS:ffff8881dbb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000045666a CR3: 00000001ac8da003 CR4: 00000000001606a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 do_wait_thread kernel/exit.c:1451 [inline]
 do_wait+0x3f7/0x930 kernel/exit.c:1522
 kernel_wait4+0x116/0x210 kernel/exit.c:1665
 SYSC_wait4 kernel/exit.c:1677 [inline]
 SyS_wait4+0x130/0x140 kernel/exit.c:1673
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
Code: 56 76 22 00 83 fd 30 0f 84 ca 0c 00 00 e8 48 76 22 00 4d 8d 6f 28 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 0f b6 04 02 <84> c0 74 08 3c 03 0f 8e 13 13 00 00 41 8b 47 28 85 c0 0f 85 35