INFO: task udevd:19320 blocked for more than 120 seconds.
      Not tainted 4.9.95-g13cc540 #2
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
udevd           D28104 19320   2039 0x00000000
 ffff8801d8493000 0000000000000000 ffff8801a419f480 ffffffff84429800
 ffff8801db221b98 ffff8801d01278e8 ffffffff839e140d ffffffff81240efb
 0000000200000001 ffff8801d8493000 00ff8801d0127aa0 ffff8801db222468
Call Trace:
 [<ffffffff839e2a0f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839ec3d0>] __rt_mutex_slowlock+0xb0/0x2d0 kernel/locking/rtmutex.c:1221
 [<ffffffff839ec787>] rt_mutex_slowlock+0x197/0x530 kernel/locking/rtmutex.c:1293
 [<ffffffff839ecb4c>] rt_mutex_fastlock kernel/locking/rtmutex.c:1439 [inline]
 [<ffffffff839ecb4c>] rt_mutex_lock+0x2c/0x30 kernel/locking/rtmutex.c:1499
 [<ffffffff826a4b2d>] process_notifier+0x9d/0x670 drivers/misc/uid_sys_stats.c:636
 [<ffffffff8119f544>] notifier_call_chain+0xb4/0x1d0 kernel/notifier.c:93
 [<ffffffff811a0aae>] __blocking_notifier_call_chain kernel/notifier.c:317 [inline]
 [<ffffffff811a0aae>] blocking_notifier_call_chain+0x7e/0xa0 kernel/notifier.c:328
 [<ffffffff8128f3ee>] profile_task_exit+0x1e/0x30 kernel/profile.c:140
 [<ffffffff8113e34e>] do_exit+0x9e/0x27c0 kernel/exit.c:740
 [<ffffffff81144d91>] do_group_exit+0x111/0x340 kernel/exit.c:941
 [<ffffffff81144fdd>] SYSC_exit_group kernel/exit.c:952 [inline]
 [<ffffffff81144fdd>] SyS_exit_group+0x1d/0x20 kernel/exit.c:950
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f2313>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/518:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646bc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813646bc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81423cb0>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3684:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d575c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3780:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f04b2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff8211c722>] n_tty_read+0x202/0x16b0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor0/3862:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor1/3868:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by kworker/dying/4733:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by kworker/dying/4791:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by kworker/dying/5181:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor5/10118:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor3/10822:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor6/12018:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor7/15718:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by kworker/dying/17365:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by kworker/dying/17374:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by udevd/19320:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by udevd/19375:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor2/24123:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by udevd/24615:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor4/27434:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor6/29020:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor6/29031:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor6/29051:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor6/29052:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor2/29021:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor2/29029:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor4/29022:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor4/29027:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor1/29023:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor1/29034:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor0/29024:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor0/29028:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor3/29030:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor3/29032:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor3/29053:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor3/29054:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor3/29055:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor7/29037:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor7/29041:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor5/29048:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor5/29049:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a0a98>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328

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

NMI backtrace for cpu 0
CPU: 0 PID: 518 Comm: khungtaskd Not tainted 4.9.95-g13cc540 #2
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d86ffd08 ffffffff81eb0ba9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b7d60 ffff8801d86ffd40
 ffffffff81ebbed7 0000000000000000 0000000000000000 0000000000000002
Call Trace:
 [<ffffffff81eb0ba9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0ba9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebbed7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebbe6a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b7e64>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81364c54>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81364c54>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81364c54>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81364c54>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119ad2d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f24dc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff839f0f16