[29962]     0 29962    17585     8439      24       3        0             0 syz-executor0
[29964]     0 29964    17618     8476      25       4        0             0 syz-executor0
[29966]     0 29966    17618     8442      24       3        0             0 syz-executor0
[29973]     0 29973    17618     8445      24       3        0             0 syz-executor4
[29976]     0 29976    17585     8439      24       3        0             0 syz-executor0
INFO: task kworker/u4:10:4988 blocked for more than 140 seconds.
      Not tainted 4.14.89+ #25
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[29980]     0 29980    17585     8441      24       3        0             0 syz-executor1
kworker/u4:10   D26264  4988      2 0x90000000
Workqueue: netns cleanup_net
Call Trace:
[29983]     0 29983    17618     8442      24       3        0             0 syz-executor0
[29984]     0 29984    17618     8477      25       4        0             0 syz-executor1
[29986]     0 29986    17585     8439      24       3        0             0 syz-executor2
[29991]     0 29991    17618     8442      24       3        0             0 syz-executor2
 schedule+0x7f/0x1b0 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+0x521/0x1480 kernel/locking/mutex.c:893
[29995]     0 29995    17585     8441      24       3        0             0 syz-executor1
[30001]     0 30001    17618     8479      25       4        0             0 syz-executor1
[30004]     0 30004    17618     8444      24       3        0             0 syz-executor1
[30009]     0 30009    17585     8439      24       3        0             0 syz-executor2
 cleanup_net+0x14c/0x880 net/core/net_namespace.c:449
[30012]     0 30012    17585     8441      24       3        0             0 syz-executor1
 process_one_work+0x86e/0x1670 kernel/workqueue.c:2114
[30016]     0 30016    17618     8442      24       3        0             0 syz-executor2
[30020]     0 30020    17618     8444      24       3        0             0 syz-executor1
 worker_thread+0xdc/0x1000 kernel/workqueue.c:2248
 kthread+0x348/0x420 kernel/kthread.c:232
[30031]     0 30031    17585     8439      24       3        0             0 syz-executor2
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
[30036]     0 30036    17618     8442      24       3        0             0 syz-executor2

Showing all locks held in the system:
[30039]     0 30039    17585     8439      24       3        0             0 syz-executor0
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.?}, at: [<ffffffffa6c04837>] debug_show_all_locks+0x74/0x20f kernel/locking/lockdep.c:4541
2 locks held by getty/1760:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffffa7740ac0>] tty_ldisc_ref_wait+0x20/0x80 drivers/tty/tty_ldisc.c:275
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffffa773bf1f>] n_tty_read+0x1ff/0x1700 drivers/tty/n_tty.c:2156
3 locks held by kworker/u4:10/4988:
 #0:  ("%s""netns"){+.+.}, at: [<ffffffffa6b29534>] process_one_work+0x784/0x1670 kernel/workqueue.c:2085
 #1:  (net_cleanup_work){+.+.}, at: [<ffffffffa6b2956c>] process_one_work+0x7bc/0x1670 kernel/workqueue.c:2089
[30040]     0 30040    17618     8476      25       4        0             0 syz-executor0
 #2:  (net_mutex){+.+.}, at: [<ffffffffa7cf900c>] cleanup_net+0x14c/0x880 net/core/net_namespace.c:449
1 lock held by syz-executor3/3927:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/4307:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/4459:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor4/4545:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/5035:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/5112:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/5116:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/5282:
[30041]     0 30041    17618     8442      24       3        0             0 syz-executor0
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/5321:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/5351:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor2/5383:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor4/5450:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/5588:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/5760:
[30049]     0 30049    17585     8439      24       3        0             0 syz-executor0
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/5858:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor2/5904:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor0/6215:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
[30052]     0 30052    17585     8477      25       4        0             0 syz-executor0
1 lock held by syz-executor3/6227:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor0/6238:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor0/6262:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/6268:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/6510:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/6535:
[30058]     0 30058    17585     8439      24       3        0             0 syz-executor0
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/6819:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor0/6832:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/6870:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor0/6906:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/6943:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/7258:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/7310:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
[30059]     0 30059    17618     8466      25       4        0             0 syz-executor0
1 lock held by syz-executor3/7546:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/7613:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor0/7748:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/7945:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/7987:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/8031:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor5/8054:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/8077:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
[30060]     0 30060    17618     8442      24       3        0             0 syz-executor0
1 lock held by syz-executor3/8172:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/8182:
[30068]     0 30068    17585     8439      24       3        0             0 syz-executor0
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/8356:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor0/8406:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/8413:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor5/8475:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/8479:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/8497:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
[30072]     0 30072    17585     8441      24       3        0             0 syz-executor1
1 lock held by syz-executor3/8892:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/9190:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/9226:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/9253:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/9282:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/9324:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/9474:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/9586:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
[30073]     0 30073    17618     8476      25       4        0             0 syz-executor1
1 lock held by syz-executor3/9605:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/9764:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/9818:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor4/9838:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/9967:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor3/10037:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/10327:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/10355:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor0/10685:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
[30074]     0 30074    17618     8444      24       3        0             0 syz-executor1
1 lock held by syz-executor1/10706:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/11311:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/12286:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor2/13115:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/13658:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/15206:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/15342:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409
1 lock held by syz-executor1/15790:
 #0:  (net_mutex){+.+.}, at: [<ffffffffa7cf9c5f>] copy_net_ns+0x14f/0x430 net/core/net_namespace.c:409

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

[30080]     0 30080    17585     8441      24       3        0             0 syz-executor1
[30081]     0 30081    17618     8442      24       3        0             0 syz-executor0
NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.89+ #25
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x11b lib/dump_stack.c:53
 nmi_cpu_backtrace.cold.0+0x47/0x85 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x121/0x146 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline]
 watchdog+0x574/0xa70 kernel/hung_task.c:252
[30085]     0 30085    17618     8444      24       3        0             0 syz-executor1
 kthread+0x348/0x420 kernel/kthread.c:232
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 1630 Comm: rs:main Q:Reg Not tainted 4.14.89+ #25
task: ffff8881d4c59780 task.stack: ffff8881d4718000
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:60
RSP: 0000:ffff8881d471ef98 EFLAGS: 00000246
RAX: 0000000000000009 RBX: ffffea00019a9bc0 RCX: 1ffffffff5195884
RDX: 1ffffd4000335378 RSI: ffffffffa894e400 RDI: ffffea00019a9bc0
RBP: ffffea00019a9be0 R08: 0000000000000000 R09: 0000000000000000
R10: ffff8881d4c5a000 R11: 0000000000000001 R12: ffffea00019a9bc0
R13: dead000000000100 R14: ffff8881d471f920 R15: ffffea00019a9bc0
FS:  00007f40b6a24700(0000) GS:ffff8881dba00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe27fab4330 CR3: 00000001d58e2006 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 __read_once_size include/linux/compiler.h:183 [inline]
 compound_head include/linux/page-flags.h:147 [inline]
 PageSwapBacked include/linux/page-flags.h:288 [inline]
 PageSwapCache include/linux/page-flags.h:333 [inline]
 page_mapping+0x9e/0x290 mm/util.c:481
 page_evictable+0x62/0x200 mm/vmscan.c:3968
 shrink_page_list+0x357/0x31d0 mm/vmscan.c:1000
 shrink_inactive_list+0x3b9/0xee0 mm/vmscan.c:1816
 shrink_list mm/vmscan.c:2175 [inline]
 shrink_node_memcg+0x5e8/0x12e0 mm/vmscan.c:2438
 shrink_node+0x301/0xbf0 mm/vmscan.c:2630
 shrink_zones mm/vmscan.c:2812 [inline]
 do_try_to_free_pages+0x349/0xde0 mm/vmscan.c:2874
 try_to_free_pages+0x204/0x6b0 mm/vmscan.c:3080
 __perform_reclaim mm/page_alloc.c:3593 [inline]
 __alloc_pages_direct_reclaim mm/page_alloc.c:3614 [inline]
 __alloc_pages_slowpath mm/page_alloc.c:4001 [inline]
 __alloc_pages_nodemask+0xa8a/0x2180 mm/page_alloc.c:4210
 __alloc_pages include/linux/gfp.h:461 [inline]
 __alloc_pages_node include/linux/gfp.h:474 [inline]
 alloc_pages_node include/linux/gfp.h:488 [inline]
 __page_cache_alloc include/linux/pagemap.h:226 [inline]
 page_cache_read mm/filemap.c:2286 [inline]
 filemap_fault+0xcdd/0x14a0 mm/filemap.c:2470
 ext4_filemap_fault+0x7d/0xb0 fs/ext4/inode.c:6179
 __do_fault+0x80/0x210 mm/memory.c:3194
 do_read_fault mm/memory.c:3604 [inline]
 do_fault mm/memory.c:3730 [inline]
 handle_pte_fault mm/memory.c:3960 [inline]
 __handle_mm_fault+0x991/0x25f0 mm/memory.c:4084
 handle_mm_fault+0x2f2/0x6eb mm/memory.c:4121
 __do_page_fault+0x45d/0xb60 arch/x86/mm/fault.c:1425
 page_fault+0x42/0x50 arch/x86/entry/entry_64.S:1104
RIP: 0000:0x2
RSP: 196fa38:0000000000000000 EFLAGS: 00000017
Code: ff ff 48 89 df e8 81 02 22 00 e9 9f fe ff ff 4c 89 e7 e8 74 02 22 00 e9 2c fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <65> 48 8b 04 25 c0 de 01 00 48 85 c0 74 1a 65 8b 15 db f5 30 59