Free memory is 41068kB above reserved
lowmemorykiller: Killing 'syz-executor495' (6182) (tgid 6182), adj 1000,
   to free 16256kB on behalf of 'syz-executor495' (20786) because
   cache 916kB is below limit 65536kB for oom_score_adj 12
   Free memory is 38068kB above reserved
INFO: task init:13289 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
init            D29336 13289      1 0x00000000
 ffff88002ea817c0 ffff8801caacee00 ffff8801d1ce0000 ffff88008a5e0000
 ffff8801db621018 ffff8801d5097738 ffffffff828075c2 0000000000000000
 ffff88002ea82070 ffffed0005d5040d 00ff88002ea817c0 ffff8801db6218f0
Call Trace:
 [<ffffffff82808aef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff828094a3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3586
 [<ffffffff8280b51d>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8280b51d>] mutex_lock_nested+0x38d/0x900 kernel/locking/mutex.c:621
 [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
 [<ffffffff81517bdd>] chrdev_open+0x22d/0x5c0 fs/char_dev.c:392
 [<ffffffff81501e3f>] do_dentry_open+0x3ef/0xc90 fs/open.c:766
 [<ffffffff8150576c>] vfs_open+0x11c/0x210 fs/open.c:879
 [<ffffffff8153c542>] do_last fs/namei.c:3410 [inline]
 [<ffffffff8153c542>] path_openat+0x542/0x2790 fs/namei.c:3534
 [<ffffffff81541617>] do_filp_open+0x197/0x270 fs/namei.c:3568
 [<ffffffff8150617d>] do_sys_open+0x30d/0x5c0 fs/open.c:1072
 [<ffffffff8150645d>] SYSC_open fs/open.c:1090 [inline]
 [<ffffffff8150645d>] SyS_open+0x2d/0x40 fs/open.c:1085
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813fe63f>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/1891:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8156cc7c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/2018:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff82815952>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff81d37362>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by init/13289:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by init/13290:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by init/13291:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by init/13292:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by init/13293:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by init/13294:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
1 lock held by syz-executor495/20823:
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81524a93>] pipe_lock_nested fs/pipe.c:66 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81524a93>] pipe_lock fs/pipe.c:74 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81524a93>] pipe_wait+0x1a3/0x1d0 fs/pipe.c:122
1 lock held by syz-executor495/20830:
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81524a93>] pipe_lock_nested fs/pipe.c:66 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81524a93>] pipe_lock fs/pipe.c:74 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81524a93>] pipe_wait+0x1a3/0x1d0 fs/pipe.c:122
1 lock held by syz-executor495/20844:
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81524a93>] pipe_lock_nested fs/pipe.c:66 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81524a93>] pipe_lock fs/pipe.c:74 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<ffffffff81524a93>] pipe_wait+0x1a3/0x1d0 fs/pipe.c:122

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #1
 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4df89 0000000000000001 0000000000000000 0000000000000002
Call Trace:
 [<ffffffff81b42e79>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81b42e79>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81b4df89>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81b4df1c>] nmi_trigger_cpumask_backtrace+0x12c/0x151 lib/nmi_backtrace.c:60
 [<ffffffff810984b4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff8131c65d>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff8131c65d>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff8131c65d>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff8131c65d>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff81142c3d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff82817a5c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 20845 Comm: syz-executor495 Not tainted 4.9.141+ #1
task: ffff880088ac5f00 task.stack: ffff88002f440000
RIP: 0010:[<ffffffff81207c21>] 
c [<ffffffff81207c21>] validate_chain kernel/locking/lockdep.c:2235 [inline]
RIP: 0010:[<ffffffff81207c21>] 
c [<ffffffff81207c21>] __lock_acquire+0x871/0x4a10 kernel/locking/lockdep.c:3345
RSP: 0018:ffff88002f447970  EFLAGS: 00000806
RAX: 0000000000000000 RBX: ffff880088ac67d8 RCX: 0000000089cc6995
RDX: 1ffff10011158cff RSI: ffff880088ac67d8 RDI: 0000000000000000
RBP: ffff88002f447b18 R08: ffff880088ac67f8 R09: 43dee6b432489250
R10: ffff880088ac5f00 R11: 0000000000000000 R12: 000000002282a77a
R13: 0000000000000000 R14: 000000002f2b1590 R15: 00000000031d7cc0
FS:  00007f02eb3dd700(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020a50000 CR3: 00000001c9f39000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 00000000025200c2
c ffff88002f4479a0
c ffffffff83ca2fd0
c 0000000000000003
c
 0000000000007924
c ffff880088ac67f0
c ffff880088ac67a0
c ffff880088ac67f8
c
 ffff880088ac67a8
c ffff880088ac67b0
c 1ffff10005e88f3a
c ffffffff83c5c2a0
c
Call Trace:
 [<ffffffff8120c8d0>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff82816dde>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:112 [inline]
 [<ffffffff82816dde>] _raw_spin_lock_irqsave+0x4e/0x70 kernel/locking/spinlock.c:159
 [<ffffffff811ed293>] __wake_up_sync_key+0x23/0x60 kernel/sched/wait.c:144
 [<ffffffff815253f1>] pipe_write+0x7f1/0xd50 fs/pipe.c:470
 [<ffffffff81508347>] new_sync_write fs/read_write.c:496 [inline]
 [<ffffffff81508347>] __vfs_write+0x3d7/0x580 fs/read_write.c:509
 [<ffffffff8150ab97>] vfs_write+0x187/0x520 fs/read_write.c:557
 [<ffffffff8150e9c9>] SYSC_write fs/read_write.c:604 [inline]
 [<ffffffff8150e9c9>] SyS_write+0xd9/0x1c0 fs/read_write.c:596
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c00 
c00 
c85 
cc0 
c44 
c8b 
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c24 
c60 
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c54 
c24 
c58 
c0f 
c84 
c1b 
c0e 
c00 
c00 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c48 
c8b 
c54 
c24 
c78 
c48 
cc1 
cea 
c03 
c0f 
cb6 
c04 
c02 
c<84> 
cc0 
c74 
c08 
c3c 
c03 
c0f 
c8e 
cfa 
c2c 
c00 
c00 
c8b 
c43 
c20 
c25 
c00 
c80 
c04 
c00 
c3d 
c