Free memory is 57720kB above reserved
lowmemorykiller: Killing 'syz-executor491' (27361) (tgid 27358), adj 1000,
   to free 2436kB on behalf of 'syz-executor491' (2159) because
   cache 2664kB is below limit 65536kB for oom_score_adj 12
   Free memory is 64112kB above reserved
INFO: task init:22798 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #23
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
init            D29336 22798      1 0x00000000
 ffff880140dedf00 ffff880092cfa100 ffff880092085280 ffff8801364b5f00
 ffff8801db621018 ffff8800ac597738 ffffffff828075c2 0000000000000000
 ffff880140dee7b0 ffffed00281bdcf5 00ff880140dedf00 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: [<ffffffff8131c2c0>] rcu_read_unlock include/linux/rcupdate.h:927 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c2c0>] rcu_lock_break kernel/hung_task.c:143 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c2c0>] check_hung_uninterruptible_tasks kernel/hung_task.c:177 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131c2c0>] watchdog+0x310/0xa20 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/1897:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff8156cc7c>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/2025:
 #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 syz-executor491/2155:
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff810b29a2>] __do_page_fault+0x272/0xa60 arch/x86/mm/fault.c:1335
1 lock held by syz-executor491/2160:
 #0:  (&mm->mmap_sem){++++++}, at: [<ffffffff810b29a2>] __do_page_fault+0x272/0xa60 arch/x86/mm/fault.c:1335
1 lock held by init/22798:
 #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/22799:
 #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/22802:
 #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/22803:
 #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/22805:
 #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/22806:
 #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

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #23
 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4df89 0000000000000001 0000000000000000 0000000000000003
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: 27362 Comm: syz-executor491 Not tainted 4.9.141+ #23
task: ffff880094494740 task.stack: ffff880092670000
RIP: 0010:[<ffffffff81205a51>] 
c [<ffffffff81205a51>] hlock_class kernel/locking/lockdep.c:142 [inline]
RIP: 0010:[<ffffffff81205a51>] 
c [<ffffffff81205a51>] mark_lock+0x1/0x1290 kernel/locking/lockdep.c:3039
RSP: 0018:ffff8800926773d0  EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff880094495090 RCX: ffff8800944950b1
RDX: 0000000000000008 RSI: ffff880094495090 RDI: ffff880094494740
RBP: ffff880092677588 R08: ffff8800944950b0 R09: 0000000000000001
R10: ffff880094494740 R11: 1ffff10012892a11 R12: 0000000000000075
R13: 0000000000000004 R14: 0000000000000000 R15: ffff8800944950b2
FS:  0000000000000000(0000) GS:ffff8801db600000(0063) knlGS:0000000009a7e840
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000080e3e48 CR3: 0000000031c02000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff880092677588
c ffffffff812079e2
c ffff880094494fdc
c 0000000000000000
c
 ffff8800926775a8
c ffffffff81207a04
c 0000000600000007
c ffff880094494740
c
 ffffffff83c73d80
c 0000000000000000
c 00000000000019ff
c ffff880094495080
c
Call Trace:
 [<ffffffff8120c8d0>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff82816c26>] __raw_spin_lock include/linux/spinlock_api_smp.h:144 [inline]
 [<ffffffff82816c26>] _raw_spin_lock+0x36/0x50 kernel/locking/spinlock.c:151
 [<ffffffff8141a061>] spin_lock include/linux/spinlock.h:302 [inline]
 [<ffffffff8141a061>] task_lock include/linux/sched.h:3257 [inline]
 [<ffffffff8141a061>] find_lock_task_mm+0xf1/0x270 mm/oom_kill.c:115
 [<ffffffff821effdf>] lowmem_scan+0x34f/0xaf0 drivers/staging/android/lowmemorykiller.c:134
 [<ffffffff81449cc6>] do_shrink_slab mm/vmscan.c:398 [inline]
 [<ffffffff81449cc6>] shrink_slab.part.8+0x3c6/0xa00 mm/vmscan.c:501
 [<ffffffff814557fd>] shrink_slab mm/vmscan.c:465 [inline]
 [<ffffffff814557fd>] shrink_node+0x1ed/0x740 mm/vmscan.c:2602
 [<ffffffff814560c7>] shrink_zones mm/vmscan.c:2749 [inline]
 [<ffffffff814560c7>] do_try_to_free_pages mm/vmscan.c:2791 [inline]
 [<ffffffff814560c7>] try_to_free_pages+0x377/0xb80 mm/vmscan.c:3002
 [<ffffffff81428a01>] __perform_reclaim mm/page_alloc.c:3324 [inline]
 [<ffffffff81428a01>] __alloc_pages_direct_reclaim mm/page_alloc.c:3345 [inline]
 [<ffffffff81428a01>] __alloc_pages_slowpath mm/page_alloc.c:3697 [inline]
 [<ffffffff81428a01>] __alloc_pages_nodemask+0x981/0x1bd0 mm/page_alloc.c:3862
 [<ffffffff814a382f>] __alloc_pages include/linux/gfp.h:433 [inline]
 [<ffffffff814a382f>] __alloc_pages_node include/linux/gfp.h:446 [inline]
 [<ffffffff814a382f>] alloc_pages_node include/linux/gfp.h:460 [inline]
 [<ffffffff814a382f>] alloc_zeroed_user_highpage_movable include/linux/highmem.h:183 [inline]
 [<ffffffff814a382f>] do_anonymous_page mm/memory.c:2761 [inline]
 [<ffffffff814a382f>] handle_pte_fault mm/memory.c:3514 [inline]
 [<ffffffff814a382f>] __handle_mm_fault mm/memory.c:3603 [inline]
 [<ffffffff814a382f>] handle_mm_fault+0x14bf/0x2350 mm/memory.c:3640
 [<ffffffff810b2b33>] __do_page_fault+0x403/0xa60 arch/x86/mm/fault.c:1406
 [<ffffffff810b31e7>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1469
 [<ffffffff828188b5>] page_fault+0x25/0x30 arch/x86/entry/entry_64.S:951
Code: 
cf3 
c03 
c03 
c85 
cc0 
c0f 
c84 
c01 
ca9 
c1f 
c00 
c48 
c83 
cc4 
c40 
c31 
cc0 
c5b 
c41 
c5c 
c41 
c5d 
c41 
c5e 
c41 
c5f 
c5d 
cc3 
c4c 
c89 
cff 
ce8 
cf6 
cd5 
c2e 
c00 
ceb 
cd7 
c0f 
c1f 
c40 
c00 
c55 
c<4c> 
c8d 
c46 
c20 
c89 
cd1 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c48 
c89 
ce5 
c41 
c57 
c