INFO: task syz-executor865:13301 blocked for more than 120 seconds.
      Not tainted 4.9.105-gd7e64f8 #40
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor865 D29720 13301   3852 0x00000004
 ffff8801d4e0c800 ffff8801bccd0a80 ffff8801d03e7480 ffff8801b8234800
 ffff8801db321c18 ffff8801cd58f8e8 ffffffff839e8c1d ffffffff8124324b
 0000000200000001 ffff8801d4e0c800 00ff8801cd58faa0 ffff8801db3224e8
Call Trace:
 [<ffffffff839ea21f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839f3be0>] __rt_mutex_slowlock+0xb0/0x2d0 kernel/locking/rtmutex.c:1221
 [<ffffffff839f3f97>] rt_mutex_slowlock+0x197/0x530 kernel/locking/rtmutex.c:1293
 [<ffffffff839f435c>] rt_mutex_fastlock kernel/locking/rtmutex.c:1439 [inline]
 [<ffffffff839f435c>] rt_mutex_lock+0x2c/0x30 kernel/locking/rtmutex.c:1499
 [<ffffffff826a88dd>] process_notifier+0x9d/0x670 drivers/misc/uid_sys_stats.c:636
 [<ffffffff811a1864>] notifier_call_chain+0xb4/0x1d0 kernel/notifier.c:93
 [<ffffffff811a2dce>] __blocking_notifier_call_chain kernel/notifier.c:317 [inline]
 [<ffffffff811a2dce>] blocking_notifier_call_chain+0x7e/0xa0 kernel/notifier.c:328
 [<ffffffff8129186e>] profile_task_exit+0x1e/0x30 kernel/profile.c:140
 [<ffffffff811404fe>] do_exit+0x9e/0x27c0 kernel/exit.c:740
 [<ffffffff81146f41>] do_group_exit+0x111/0x340 kernel/exit.c:941
 [<ffffffff8114718d>] SYSC_exit_group kernel/exit.c:952 [inline]
 [<ffffffff8114718d>] SyS_exit_group+0x1d/0x20 kernel/exit.c:950
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81366b9c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81366b9c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81426180>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/3774:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f7cc2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff82120062>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor865/13301:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13317:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13307:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13316:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13313:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13309:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13314:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13310:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13318:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13311:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13315:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13319:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328
1 lock held by syz-executor865/13320:
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] __blocking_notifier_call_chain kernel/notifier.c:316 [inline]
 #0:  ((task_exit_notifier).rwsem){.+.+..}, at: [<ffffffff811a2db8>] blocking_notifier_call_chain+0x68/0xa0 kernel/notifier.c:328

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

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.105-gd7e64f8 #40
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d89b7d08 ffffffff81eb41a9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b96a0 ffff8801d89b7d40
 ffffffff81ebf4a7 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb41a9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb41a9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebf4a7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebf43a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b97a4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81367134>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81367134>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81367134>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81367134>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d04d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f9cdc>] 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 0xffffffff839f8726