INFO: task syz-executor662:3918 blocked for more than 140 seconds.
      Not tainted 4.9.112-g9e79039 #7
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor662 D28368  3918   3914 0x00000004
 ffff8801b545e000 0000000000000000 ffff8801d750da40 ffff8801d9a6b000
 ffff8801db321c18 ffff8801c6bb75d8 ffffffff839e907d ffffffff81235667
 0000000000000000 ffff8801b545e8c0 0000000600000007 ffff8801db3224e8
Call Trace:
 [<ffffffff839ea67f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839f5cb8>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline]
 [<ffffffff839f5cb8>] rwsem_down_write_failed+0x598/0x990 kernel/locking/rwsem-xadd.c:555
 [<ffffffff81ee7527>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 [<ffffffff839f3a8c>] __down_write arch/x86/include/asm/rwsem.h:125 [inline]
 [<ffffffff839f3a8c>] down_write+0x5c/0xa0 kernel/locking/rwsem.c:54
 [<ffffffff8191bbae>] inode_lock include/linux/fs.h:766 [inline]
 [<ffffffff8191bbae>] fuse_reverse_inval_entry+0xae/0x670 fs/fuse/dir.c:1011
 [<ffffffff8190d5de>] fuse_notify_delete fs/fuse/dev.c:1536 [inline]
 [<ffffffff8190d5de>] fuse_notify fs/fuse/dev.c:1768 [inline]
 [<ffffffff8190d5de>] fuse_dev_do_write+0x98e/0x20a0 fs/fuse/dev.c:1843
 [<ffffffff8190fa2b>] fuse_dev_write+0x14b/0x1e0 fs/fuse/dev.c:1929
 [<ffffffff8156ecb0>] new_sync_write fs/read_write.c:496 [inline]
 [<ffffffff8156ecb0>] __vfs_write+0x3e0/0x580 fs/read_write.c:509
 [<ffffffff81572aa7>] vfs_write+0x187/0x530 fs/read_write.c:557
 [<ffffffff815768d9>] SYSC_write fs/read_write.c:604 [inline]
 [<ffffffff815768d9>] SyS_write+0xd9/0x1c0 fs/read_write.c:596
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9f53>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136675c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136675c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81425de7>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/3779:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f8122>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211edc2>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
2 locks held by syz-executor662/3918:
 #0:  (&fc->killsb){.+.+..}, at: [<ffffffff8190e754>] fuse_notify_delete fs/fuse/dev.c:1533 [inline]
 #0:  (&fc->killsb){.+.+..}, at: [<ffffffff8190e754>] fuse_notify fs/fuse/dev.c:1768 [inline]
 #0:  (&fc->killsb){.+.+..}, at: [<ffffffff8190e754>] fuse_dev_do_write+0x1b04/0x20a0 fs/fuse/dev.c:1843
 #1:  (&type->i_mutex_dir_key#3){++++.+}, at: [<ffffffff8191bbae>] inode_lock include/linux/fs.h:766 [inline]
 #1:  (&type->i_mutex_dir_key#3){++++.+}, at: [<ffffffff8191bbae>] fuse_reverse_inval_entry+0xae/0x670 fs/fuse/dir.c:1011

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

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.112-g9e79039 #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8637d08 ffffffff81eb3249 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b9bd0 ffff8801d8637d40
 ffffffff81ebe547 0000000000000000 0000000000000000 0000000000000002
Call Trace:
 [<ffffffff81eb3249>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb3249>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebe547>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebe4da>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b9cd4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81366cf4>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366cf4>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366cf4>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366cf4>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d0bd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839fa11c>] 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: 3917 Comm: syz-executor662 Not tainted 4.9.112-g9e79039 #7
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9409800 task.stack: ffff8801b6958000
RIP: 0010:[<ffffffff81236775>] 
c [<ffffffff81236775>] mark_irqflags kernel/locking/lockdep.c:2953 [inline]
RIP: 0010:[<ffffffff81236775>] 
c [<ffffffff81236775>] __lock_acquire+0x5a5/0x4070 kernel/locking/lockdep.c:3302
RSP: 0018:ffff8801b695f140  EFLAGS: 00000006
RAX: 0000000000000000 RBX: ffff8801d940a118 RCX: ffff8801d940a139
RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff8801d940a13c
RBP: ffff8801b695f2f0 R08: 0000000000000001 R09: 0000000000000001
R10: ffff8801d9409800 R11: 1ffff1003b281422 R12: 00000000000003e4
R13: 0000000000000002 R14: 0000000000000000 R15: ffff8801d940a13a
FS:  00007ff090162700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcbbc29de8 CR3: 00000001d98d3000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000000046
c 0000000000000001
c ffff8801d940a0c8
c ffffed003b281418
c
 ffff8801d9409800
c dffffc0000000000
c ffff8801b695f1c0
c ffffffff81235667
c
 0000000000000000
c ffff8801d940a0c0
c ffffffff855f1f10
c ffff8801d9409800
c
Call Trace:
 [<ffffffff8123acb0>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff839f9e9e>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:112 [inline]
 [<ffffffff839f9e9e>] _raw_spin_lock_irqsave+0x4e/0x62 kernel/locking/spinlock.c:159
 [<ffffffff812215db>] prepare_to_wait_event+0x6b/0x450 kernel/sched/wait.c:213
 [<ffffffff81907b5e>] request_wait_answer+0x22e/0x6e0 fs/fuse/dev.c:459
 [<ffffffff81908669>] __fuse_request_send+0x109/0x1b0 fs/fuse/dev.c:480
 [<ffffffff8190876d>] fuse_request_send+0x5d/0x70 fs/fuse/dev.c:493
 [<ffffffff819129c4>] fuse_simple_request+0x2f4/0x660 fs/fuse/dev.c:551
 [<ffffffff8191ad63>] fuse_lookup_name+0x253/0x5d0 fs/fuse/dir.c:369
 [<ffffffff8191b1cd>] fuse_lookup+0xed/0x3a0 fs/fuse/dir.c:406
 [<ffffffff81594dae>] lookup_slow+0x23e/0x470 fs/namei.c:1668
 [<ffffffff815a1336>] walk_component+0x716/0x1bb0 fs/namei.c:1784
 [<ffffffff815a3c96>] lookup_last fs/namei.c:2266 [inline]
 [<ffffffff815a3c96>] path_lookupat.isra.41+0x186/0x410 fs/namei.c:2283
 [<ffffffff815a9747>] filename_lookup.part.55+0x177/0x370 fs/namei.c:2317
 [<ffffffff815a9b03>] filename_lookup fs/namei.c:2310 [inline]
 [<ffffffff815a9b03>] user_path_at_empty+0x53/0x70 fs/namei.c:2578
 [<ffffffff81580ae6>] user_path_at include/linux/namei.h:55 [inline]
 [<ffffffff81580ae6>] vfs_fstatat+0xc6/0x170 fs/stat.c:106
 [<ffffffff81581c96>] vfs_stat fs/stat.c:123 [inline]
 [<ffffffff81581c96>] SYSC_newstat+0x86/0xf0 fs/stat.c:270
 [<ffffffff8158209d>] SyS_newstat+0x1d/0x30 fs/stat.c:266
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9f53>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c48 
c89 
cca 
c48 
cc1 
cea 
c03 
c0f 
cb6 
c04 
c02 
c48 
c89 
cca 
c83 
ce2 
c07 
c38 
cd0 
c7f 
c08 
c84 
cc0 
c0f 
c85 
c1c 
c2f 
c00 
c00 
c80 
c7b 
c21 
c00 
c<0f> 
c88 
c94 
c00 
c00 
c00 
c49 
c8d 
cba 
c48 
c10 
c00 
c00 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
c