Free memory is -31880kB above reserved
lowmemorykiller: Killing 'syz-executor.5' (13455) (tgid 13450), adj 1000,
   to free 32kB on behalf of 'syz-fuzzer' (2030) because
   cache 88kB is below limit 6144kB for oom_score_adj 0
   Free memory is -31852kB above reserved
INFO: task init:13554 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            D
24760 13554      1 0x00000000
 0000000000000000 ffff8801d333a100 ffff8801d8410000 ffff8801db721018
 ffff88019912f738 ffffffff828075c2 0000000000000000 ffff8801c7c788b0
 ffffed0038f8f115 00ff8801c7c78000 ffff8801db7218f0Call 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]
 (rcu_read_lock){......}, at: [<ffffffff8131c0cc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 (tasklist_lock){.+.?..}, at: [<ffffffff813fe63f>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
 #0: 
 (&tty->ldisc_sem){++++++}, at: [<ffffffff82815952>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff81d37362>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
 #0: 
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
 #0: 
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
 #0: 
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
 #0: 
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
 #0: 
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open+0x476/0xdf0 drivers/tty/tty_io.c:2130
 #0: 
 (tty_mutex){+.+.+.}, at: [<ffffffff81d2bb96>] tty_open_by_driver drivers/tty/tty_io.c:2052 [inline]
 (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+ #1
 ffff8801d9907d08
 ffffffff81b42e79 0000000000000000 0000000000000001 0000000000000001
 0000000000000001 ffffffff810983b0 ffff8801d9907d40 ffffffff81b4df89
 0000000000000001 0000000000000000 0000000000000002Call 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: 2030 Comm: syz-fuzzer Not tainted 4.9.141+ #1
task: ffff8801d1952f80 task.stack: ffff8801c4ca0000
RIP: 0010:[<ffffffff81207aa9>] 
c [<ffffffff81207aa9>] separate_irq_context kernel/locking/lockdep.c:2974 [inline]
RIP: 0010:[<ffffffff81207aa9>] 
c [<ffffffff81207aa9>] __lock_acquire+0x6f9/0x4a10 kernel/locking/lockdep.c:3336
RSP: 0000:ffff8801c4ca70f0  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8801d19538d0 RCX: 1ffff1003a32a71e
RDX: 1ffff1003a32a71a RSI: ffff8801d19538d0 RDI: ffffffff83c6aae0
RBP: ffff8801c4ca72a0 R08: ffff8801d19538f0 R09: 0000000000000000
R10: ffff8801d1952f80 R11: 0000000000000000 R12: 000000000000001e
R13: 0000000000000004 R14: 000000000000001e R15: 42561911fe00023c
FS:  000000c420028068(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004374f8 CR3: 00000001cfef5000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d1953820
c ffff8801d19538f0
c ffffffff83c73d80
c ffff8801d19538a8
c
 000000000000322a
c ffff8801d19538e8
c ffffffff83c73d80
c ffff8801d19538f0
c
 0000000000004416
c ffff8801d1953910
c ffff8801d1953820
c ffff8801d1953918
c
Call Trace:
 [<ffffffff8120c8d0>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff81419fb6>] rcu_lock_acquire include/linux/rcupdate.h:493 [inline]
 [<ffffffff81419fb6>] rcu_read_lock include/linux/rcupdate.h:875 [inline]
 [<ffffffff81419fb6>] find_lock_task_mm+0x46/0x270 mm/oom_kill.c:112
 [<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
 [<ffffffff8143564a>] __alloc_pages include/linux/gfp.h:433 [inline]
 [<ffffffff8143564a>] __alloc_pages_node include/linux/gfp.h:446 [inline]
 [<ffffffff8143564a>] alloc_pages_node include/linux/gfp.h:460 [inline]
 [<ffffffff8143564a>] __page_cache_alloc include/linux/pagemap.h:208 [inline]
 [<ffffffff8143564a>] __do_page_cache_readahead+0x21a/0x8b0 mm/readahead.c:183
 [<ffffffff81415534>] ra_submit mm/internal.h:59 [inline]
 [<ffffffff81415534>] do_sync_mmap_readahead mm/filemap.c:2066 [inline]
 [<ffffffff81415534>] filemap_fault+0x924/0x1110 mm/filemap.c:2143
 [<ffffffff816e7721>] ext4_filemap_fault+0x71/0xa0 fs/ext4/inode.c:5853
 [<ffffffff81492ef3>] __do_fault+0x223/0x500 mm/memory.c:2833
 [<ffffffff814a3696>] do_read_fault mm/memory.c:3180 [inline]
 [<ffffffff814a3696>] do_fault mm/memory.c:3315 [inline]
 [<ffffffff814a3696>] handle_pte_fault mm/memory.c:3516 [inline]
 [<ffffffff814a3696>] __handle_mm_fault mm/memory.c:3603 [inline]
 [<ffffffff814a3696>] handle_mm_fault+0x1326/0x2350 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: 
c8b 
cba 
ca0 
c08 
c00 
c00 
c45 
c31 
cdb 
c45 
c85 
ced 
c41 
c0f 
c94 
cc3 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c48 
c89 
cda 
c48 
cc1 
cea 
c03 
c80 
c3c 
c02 
c00 
c0f 
c85 
cc3 
c2c 
c00 
c00 
c<48> 
c8b 
c94 
c24 
c80 
c00 
c00 
c00 
c4c 
c89 
c3b 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c