Free memory is -13256kB above reserved
lowmemorykiller: Killing 'syz-executor4' (12769) (tgid 12765), adj 1000,
   to free 49328kB on behalf of 'udevd' (470) because
   cache 232kB is below limit 6144kB for oom_score_adj 0
   Free memory is -13256kB above reserved
INFO: task syz-executor4:12774 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #23
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D29816 12774   2099 0x20020004
 ffff8801aa12df00 ffff8801d0bddd80 ffff880168099600 ffff8801cea7c740
 ffff8801db621018 ffff88003b837a88 ffffffff828075c2 ffff88003b837b08
 ffff8801aa12df00 ffffffff810efada 00fffc0000000000 ffff8801db6218f0
Call Trace:
 [<ffffffff82808aef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff822acffc>] __lock_sock+0x13c/0x250 net/core/sock.c:2035
 [<ffffffff822ad206>] lock_sock_nested+0xf6/0x120 net/core/sock.c:2505
 [<ffffffff827d1f3f>] lock_sock include/net/sock.h:1404 [inline]
 [<ffffffff827d1f3f>] packet_setsockopt+0x50f/0x2630 net/packet/af_packet.c:3668
 [<ffffffff827d4141>] compat_packet_setsockopt+0xe1/0x140 net/packet/af_packet.c:4016
 [<ffffffff8238f7d9>] C_SYSC_setsockopt net/compat.c:399 [inline]
 [<ffffffff8238f7d9>] compat_SyS_setsockopt+0x169/0x550 net/compat.c:382
 [<ffffffff81006311>] do_syscall_32_irqs_on arch/x86/entry/common.c:328 [inline]
 [<ffffffff81006311>] do_fast_syscall_32+0x2f1/0xa10 arch/x86/entry/common.c:390
 [<ffffffff82818de0>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

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
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-executor3/11912:
 #0:  (&sig->cred_guard_mutex){+.+.+.}, at: [<ffffffff81520d73>] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369
1 lock held by syz-executor3/11965:
 #0:  (&sig->cred_guard_mutex){+.+.+.}, at: [<ffffffff81520d73>] prepare_bprm_creds+0x53/0x110 fs/exec.c:1369
2 locks held by syz-executor3/27991:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff82815952>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&tty->atomic_write_lock){+.+.+.}, at: [<ffffffff81d1f7e1>] tty_write_lock+0x21/0x60 drivers/tty/tty_io.c:1107

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

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.141+ #23
 ffff8801d9907d08 ffffffff81b42e79 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810983b0 ffff8801d9907d40
 ffffffff81b4df89 0000000000000000 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 1 Comm: init Not tainted 4.9.141+ #23
task: ffff8801da5f8000 task.stack: ffff8801da600000
RIP: 0010:[<ffffffff8141a01a>] 
c [<ffffffff8141a01a>] __read_once_size include/linux/compiler.h:243 [inline]
RIP: 0010:[<ffffffff8141a01a>] 
c [<ffffffff8141a01a>] find_lock_task_mm+0xaa/0x270 mm/oom_kill.c:114
RSP: 0018:ffff8801da607328  EFLAGS: 00000246
RAX: dffffc0000000000 RBX: ffff88018f900b80 RCX: 1ffff10031f20172
RDX: 0000000000000000 RSI: ffffffff81419fd6 RDI: ffffffff82e76408
RBP: ffff8801da607360 R08: ffff8801da5f8970 R09: 0bdf069b8bf16716
R10: ffff8801da5f8000 R11: 0000000000000001 R12: ffff880069ca0000
R13: ffff88018f900b90 R14: ffff8801d9d917c0 R15: ffff880069ca0738
FS:  00007f413a9a67a0(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0a27c1ee40 CR3: 00000001d4d5e000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff81419f70
c ffff8801d9d91f80
c ffff880069ca0000
c dffffc0000000000
c
 ffff880069ca0418
c ffff8801d9d917c0
c 0000000000000600
c ffff8801da607410
c
 ffffffff821effdf
c ffffffff821efede
c ffff880100000001
c 00000000000000e8
c
Call Trace:
 [<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: 
c80 
c3c 
c01 
c00 
c0f 
c85 
cb5 
c01 
c00 
c00 
c49 
c8b 
c9c 
c24 
c38 
c07 
c00 
c00 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c4c 
c8d 
c6b 
c10 
c4c 
c89 
ce9 
c48 
cc1 
ce9 
c03 
c80 
c3c 
c01 
c00 
c<0f> 
c85 
c81 
c01 
c00 
c00 
c48 
c8b 
c43 
c10 
c48 
c8d 
c98 
c28 
cfa 
cff 
cff 
c4c 
c39 
ce8 
c0f 
c