Free memory is 51744kB above reserved
lowmemorykiller: Killing 'syz-executor.2' (22394) (tgid 22394), adj 1000,
   to free 12324kB on behalf of 'syz-executor.3' (25277) because
   cache 14216kB is below limit 65536kB for oom_score_adj 12
   Free memory is 51124kB above reserved
INFO: task init:5920 blocked for more than 140 seconds.
      Not tainted 4.4.174+ #17
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
init            D ffff880071317718 29280  5920      1 0x00000000
 ffff880071317718 ffff8800b6582f80 4c00839bf2097ec1 ffff8800b6582f80
 0000000000000000 ffff8800b6583800 ffff8801db61f180 ffff8801db61f1a8
 ffff8801db61e898 ffff88004c5e97c0 ffff8800b6582f80 ffffed000e262001
Call Trace:
 [<ffffffff82709b79>] schedule+0x99/0x1d0 kernel/sched/core.c:3355
 [<ffffffff8270a333>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3388
 [<ffffffff8270c492>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff8270c492>] mutex_lock_nested+0x3c2/0xb80 kernel/locking/mutex.c:621
 [<ffffffff81c8b2aa>] tty_open+0x56a/0xf50 drivers/tty/tty_io.c:2067
 [<ffffffff814a3ec0>] chrdev_open+0x230/0x630 fs/char_dev.c:388
 [<ffffffff8149154f>] do_dentry_open+0x38f/0xbd0 fs/open.c:749
 [<ffffffff81494d3b>] vfs_open+0x10b/0x210 fs/open.c:862
 [<ffffffff814c5ddf>] do_last fs/namei.c:3269 [inline]
 [<ffffffff814c5ddf>] path_openat+0x136f/0x4470 fs/namei.c:3406
 [<ffffffff814ccab1>] do_filp_open+0x1a1/0x270 fs/namei.c:3440
 [<ffffffff81495668>] do_sys_open+0x2f8/0x600 fs/open.c:1038
 [<ffffffff8149599d>] SYSC_open fs/open.c:1056 [inline]
 [<ffffffff8149599d>] SyS_open+0x2d/0x40 fs/open.c:1051
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
1 lock held by init/5920:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff81c8b2aa>] tty_open+0x56a/0xf50 drivers/tty/tty_io.c:2067
Sending NMI to all CPUs:
NMI backtrace for cpu 0
CPU: 0 PID: 3 Comm: ksoftirqd/0 Not tainted 4.4.174+ #17
task: ffff8801da5f2f80 task.stack: ffff8801da628000
RIP: 0010:[<ffffffff8120661a>]  [<ffffffff8120661a>] __lock_release kernel/locking/lockdep.c:3434 [inline]
RIP: 0010:[<ffffffff8120661a>]  [<ffffffff8120661a>] lock_release+0x3ba/0xcf0 kernel/locking/lockdep.c:3611
RSP: 0018:ffff8801da62fa10  EFLAGS: 00000046
RAX: 0000000000000003 RBX: ffff8801da5f3848 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8414eaa0 RDI: 0000000000000000
RBP: ffff8801da62fac0 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000
R13: ffff8801da5f3820 R14: 0000000000000000 R15: ffff8801da5f386a
FS:  0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000008482a98 CR3: 000000017112d000 CR4: 00000000001606b0
Stack:
 ffff8801da5f2f80 ffffffff8414eaa0 0000000000000000 0000000000000000
 0000000000000000 ffff8801da62fab8 0000000000000046 0000000000000000
 ffffffff81b0c604 ffff8801da5f3840 0000000000000000 ffff8801da5f3848
Call Trace:
 [<ffffffff82717fef>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
 [<ffffffff82717fef>] _raw_spin_unlock_irqrestore+0x1f/0x70 kernel/locking/spinlock.c:191
 [<ffffffff81b0c6e4>] debug_object_deactivate+0x1e4/0x360 lib/debugobjects.c:494
 [<ffffffff81245a82>] debug_rcu_head_unqueue kernel/rcu/rcu.h:87 [inline]
 [<ffffffff81245a82>] rcu_do_batch kernel/rcu/tree.c:2704 [inline]
 [<ffffffff81245a82>] invoke_rcu_callbacks kernel/rcu/tree.c:2973 [inline]
 [<ffffffff81245a82>] __rcu_process_callbacks kernel/rcu/tree.c:2940 [inline]
 [<ffffffff81245a82>] rcu_process_callbacks+0xa42/0x14b0 kernel/rcu/tree.c:2957
 [<ffffffff8271bb16>] __do_softirq+0x226/0xa3f kernel/softirq.c:273
 [<ffffffff810e185e>] run_ksoftirqd kernel/softirq.c:662 [inline]
 [<ffffffff810e185e>] run_ksoftirqd+0x2e/0x60 kernel/softirq.c:654
 [<ffffffff8113e22b>] smpboot_thread_fn+0x5eb/0x980 kernel/smpboot.c:163
 [<ffffffff811342c3>] kthread+0x273/0x310 kernel/kthread.c:211
 [<ffffffff82718fc5>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:537
Code: c1 ea 03 0f b6 04 02 84 c0 74 0f 3c 03 7f 0b 89 4d c0 e8 9a e8 27 00 8b 4d c0 66 83 6b 22 10 66 f7 43 22 f0 ff 0f 85 6e 01 00 00 <48> b8 00 00 00 00 00 fc ff df 48 8b 55 98 48 c1 ea 03 0f b6 04 
NMI backtrace for cpu 1
CPU: 1 PID: 20 Comm: khungtaskd Not tainted 4.4.174+ #17
task: ffff8801da6c2f80 task.stack: ffff8800001e8000
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] _flat_send_IPI_mask arch/x86/kernel/apic/apic_flat_64.c:62 [inline]
RIP: 0010:[<ffffffff8109b617>]  [<ffffffff8109b617>] flat_send_IPI_mask+0xf7/0x1b0 arch/x86/kernel/apic/apic_flat_64.c:69
RSP: 0018:ffff8800001efc88  EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000c00 RCX: 0000000000000000
RDX: 0000000000000c00 RSI: 0000000000000000 RDI: ffffffffff5fc300
RBP: ffff8800001efcb8 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000246
R13: 0000000003000000 R14: ffffffff82e5f2e0 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe831f4338 CR3: 00000001d4185000 CR4: 00000000001606b0
Stack:
 0000000000000001 ffffffff82e5f2e0 ffffffff831a6ac0 fffffbfff0634c34
 000000000001b6c0 0000000000000008 ffff8800001efcd8 ffffffff81092bee
 0000000000000008 ffffffff82924260 ffff8800001efd30 ffffffff81ab8252
Call Trace:
 [<ffffffff81092bee>] nmi_raise_cpu_backtrace+0x5e/0x80 arch/x86/kernel/apic/hw_nmi.c:33
 [<ffffffff81ab8252>] nmi_trigger_all_cpu_backtrace.cold+0xa1/0xae lib/nmi_backtrace.c:85
 [<ffffffff81092ca4>] arch_trigger_all_cpu_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 [<ffffffff813b4762>] trigger_all_cpu_backtrace include/linux/nmi.h:44 [inline]
 [<ffffffff813b4762>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813b4762>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813b4762>] watchdog.cold+0xd3/0xee kernel/hung_task.c:238
 [<ffffffff811342c3>] kthread+0x273/0x310 kernel/kthread.c:211
 [<ffffffff82718fc5>] ret_from_fork+0x55/0x80 arch/x86/entry/entry_64.S:537
Code: 00 c3 5f ff 80 e6 10 75 e1 41 c1 e5 18 44 89 2c 25 10 c3 5f ff 44 89 fa 09 da 80 cf 04 41 83 ff 02 0f 44 d3 89 14 25 00 c3 5f ff <41> f7 c4 00 02 00 00 75 1e 4c 89 e7 57 9d 0f 1f 44 00 00 e8 f1