Free memory is -13548kB above reserved
lowmemorykiller: Killing 'syz-executor3' (15877) (tgid 15872), adj 1000,
   to free 32952kB on behalf of 'syz-fuzzer' (2039) because
   cache 224kB is below limit 6144kB for oom_score_adj 0
   Free memory is -13548kB above reserved
INFO: task syz-executor1:15930 blocked for more than 140 seconds.
      Not tainted 4.9.141+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1   D29352 15930   2093 0x00000000
 ffff8801d76f0000 ffff8801d1ef6300 ffff8801d12b0b00 ffff8801ce36c740
 ffff8801db621018 ffff8801d0ae7750 ffffffff828075c2 ffff8801d0ae7728
 ffffffff81206da7 0000000000000000 00ff8801d76f08a8 ffff8801db6218f0
Call Trace:
 [<ffffffff82808aef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff828128ea>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline]
 [<ffffffff828128ea>] rwsem_down_write_failed+0x39a/0x730 kernel/locking/rwsem-xadd.c:555
 [<ffffffff81b75467>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 [<ffffffff8281170c>] __down_write arch/x86/include/asm/rwsem.h:125 [inline]
 [<ffffffff8281170c>] down_write+0x5c/0xa0 kernel/locking/rwsem.c:54
 [<ffffffff81503378>] inode_lock include/linux/fs.h:766 [inline]
 [<ffffffff81503378>] do_truncate2+0x128/0x1f0 fs/open.c:61
 [<ffffffff8153cb86>] handle_truncate fs/namei.c:2990 [inline]
 [<ffffffff8153cb86>] do_last fs/namei.c:3419 [inline]
 [<ffffffff8153cb86>] path_openat+0xb86/0x2790 fs/namei.c:3534
 [<ffffffff81541617>] do_filp_open+0x197/0x270 fs/namei.c:3568
 [<ffffffff8150617d>] do_sys_open+0x30d/0x5c0 fs/open.c:1072
 [<ffffffff815064d7>] SYSC_open fs/open.c:1090 [inline]
 [<ffffffff815064d7>] SyS_open fs/open.c:1085 [inline]
 [<ffffffff815064d7>] SYSC_creat fs/open.c:1110 [inline]
 [<ffffffff815064d7>] SyS_creat+0x27/0x30 fs/open.c:1108
 [<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
2 locks held by getty/2020:
 #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
2 locks held by kworker/u4:5/2117:
 #0:  ("events_unbound"){.+.+.+}, at: [<ffffffff81130f0c>] process_one_work+0x73c/0x15f0 kernel/workqueue.c:2085
 #1:  ((&sub_info->work)){+.+.+.}, at: [<ffffffff81130f44>] process_one_work+0x774/0x15f0 kernel/workqueue.c:2089
2 locks held by syz-executor1/15930:
 #0:  (sb_writers#4){.+.+.+}, at: [<ffffffff815755ef>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#4){.+.+.+}, at: [<ffffffff815755ef>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&sb->s_type->i_mutex_key#9){++++++}, at: [<ffffffff81503378>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&sb->s_type->i_mutex_key#9){++++++}, at: [<ffffffff81503378>] do_truncate2+0x128/0x1f0 fs/open.c:61
3 locks held by syz-executor2/15935:
 #0:  (sb_writers#6){.+.+.+}, at: [<ffffffff815755ef>] sb_start_write include/linux/fs.h:1573 [inline]
 #0:  (sb_writers#6){.+.+.+}, at: [<ffffffff815755ef>] mnt_want_write+0x3f/0xb0 fs/namespace.c:391
 #1:  (&type->i_mutex_dir_key#4/1){+.+.+.}, at: [<ffffffff815408ff>] inode_lock_nested include/linux/fs.h:801 [inline]
 #1:  (&type->i_mutex_dir_key#4/1){+.+.+.}, at: [<ffffffff815408ff>] do_unlinkat+0x29f/0x660 fs/namei.c:4067
 #2:  (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<ffffffff8152c63d>] inode_lock include/linux/fs.h:766 [inline]
 #2:  (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [<ffffffff8152c63d>] vfs_unlink2+0xcd/0x470 fs/namei.c:4001

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

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: 1 Comm: init Not tainted 4.9.141+ #1
task: ffff8801da5f8000 task.stack: ffff8801da600000
RIP: 0010:[<ffffffff81243c28>] 
c [<ffffffff81243c28>] debug_lockdep_rcu_enabled+0x18/0x90 kernel/rcu/update.c:264
RSP: 0018:ffff8801da607078  EFLAGS: 00000083
RAX: dffffc0000000000 RBX: 0000000000000246 RCX: 0000000000000000
RDX: ffffffff833e7adc RSI: 0000000000000000 RDI: ffffffff833e7adc
RBP: ffff8801da607078 R08: 0000000000000001 R09: 0000000000000000
R10: ffff8801da5f8000 R11: 0000000000000000 R12: ffff8801c92be6d8
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f179031a7a0(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000040c026 CR3: 00000001d4d77000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801da6070f0
c ffffffff8120c93e
c 0000000000000000
c 0000000000000002
c
 ffff8801da607110
c ffff8801da6070e0
c ffffffff81ba7d7b
c ffffffff81419f70
c
 0000000000000000
c 00000001c92bdf00
c ffff8801c92be6c0
c ffff8801c92bdf00
c
Call Trace:
 [<ffffffff8120c93e>] trace_lock_acquire include/trace/events/lock.h:12 [inline]
 [<ffffffff8120c93e>] lock_acquire+0x19e/0x3e0 kernel/locking/lockdep.c:3755
 [<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
 [<ffffffff81415701>] __alloc_pages include/linux/gfp.h:433 [inline]
 [<ffffffff81415701>] __alloc_pages_node include/linux/gfp.h:446 [inline]
 [<ffffffff81415701>] alloc_pages_node include/linux/gfp.h:460 [inline]
 [<ffffffff81415701>] __page_cache_alloc include/linux/pagemap.h:208 [inline]
 [<ffffffff81415701>] page_cache_read mm/filemap.c:2007 [inline]
 [<ffffffff81415701>] filemap_fault+0xaf1/0x1110 mm/filemap.c:2192
 [<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
 [<ffffffff810002b8>] ? 0xffffffff810002b8
 [<ffffffff8153eceb>] getname_flags+0x10b/0x550 fs/namei.c:148
 [<ffffffff8153fa2f>] user_path_at_empty+0x2f/0x70 fs/namei.c:2578
 [<ffffffff81518fe6>] user_path_at include/linux/namei.h:55 [inline]
 [<ffffffff81518fe6>] vfs_fstatat+0xc6/0x170 fs/stat.c:106
 [<ffffffff8151a196>] vfs_stat fs/stat.c:123 [inline]
 [<ffffffff8151a196>] SYSC_newstat fs/stat.c:270 [inline]
 [<ffffffff8151a196>] SyS_newstat+0x86/0xf0 fs/stat.c:266
 [<ffffffff810056ef>] do_syscall_64+0x19f/0x550 arch/x86/entry/common.c:285
 [<ffffffff82817893>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
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