FAT-fs (loop0): error, invalid access to FAT (entry 0x000003dc)
FAT-fs (loop0): error, invalid access to FAT (entry 0x00000202)
FAT-fs (loop3): bogus number of reserved sectors
FAT-fs (loop3): Can't find a valid FAT filesystem
INFO: task syz-executor4:11449 blocked for more than 140 seconds.
      Not tainted 4.9.121-g681e57b #25
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D27160 11449   3884 0x00000004
 ffff88019d7f6000 ffff8801ccaaef40 ffff8801d45f5500 ffff8801ccae4800
 ffff8801db321c18 ffff8801aaf57650 ffffffff839eedcd dffffc0000000000
 ffff8801cbeaed70 ffff8801aaf57610 00ff88019d7f68c0 ffff8801db3224e8
Call Trace:
 [<ffffffff839f03cf>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff815cace2>] d_wait_lookup fs/dcache.c:2454 [inline]
 [<ffffffff815cace2>] d_alloc_parallel+0xeb2/0x17c0 fs/dcache.c:2536
 [<ffffffff81597e2c>] lookup_slow+0x19c/0x470 fs/namei.c:1650
 [<ffffffff815a4456>] walk_component+0x716/0x1bb0 fs/namei.c:1784
 [<ffffffff815a6db6>] lookup_last fs/namei.c:2266 [inline]
 [<ffffffff815a6db6>] path_lookupat.isra.41+0x186/0x410 fs/namei.c:2283
 [<ffffffff815ac867>] filename_lookup.part.55+0x177/0x370 fs/namei.c:2317
 [<ffffffff815acc23>] filename_lookup fs/namei.c:2310 [inline]
 [<ffffffff815acc23>] user_path_at_empty+0x53/0x70 fs/namei.c:2578
 [<ffffffff81583c06>] user_path_at include/linux/namei.h:55 [inline]
 [<ffffffff81583c06>] vfs_fstatat+0xc6/0x170 fs/stat.c:106
 [<ffffffff81584db6>] vfs_stat fs/stat.c:123 [inline]
 [<ffffffff81584db6>] SYSC_newstat+0x86/0xf0 fs/stat.c:270
 [<ffffffff815851bd>] SyS_newstat+0x1d/0x30 fs/stat.c:266
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839ffcd3>] 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: [<ffffffff8136862c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136862c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81427e98>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/3781:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839fde72>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff82123b32>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
1 lock held by syz-executor4/11449:
 #0:  (&type->i_mutex_dir_key#4){++++++}, at: [<ffffffff81597dd1>] inode_lock_shared include/linux/fs.h:776 [inline]
 #0:  (&type->i_mutex_dir_key#4){++++++}, at: [<ffffffff81597dd1>] lookup_slow+0x141/0x470 fs/namei.c:1645

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

NMI backtrace for cpu 1
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.121-g681e57b #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8607d08 ffffffff81eb7e29 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b9fa0 ffff8801d8607d40
 ffffffff81ec3137 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb7e29>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb7e29>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ec3137>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ec30ca>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810ba0a4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81368bc4>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81368bc4>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81368bc4>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81368bc4>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119ef5d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839ffe9c>] 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: 11442 Comm: syz-executor4 Not tainted 4.9.121-g681e57b #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff88019e2ce000 task.stack: ffff88019d718000
RIP: 0010:[<ffffffff8123842b>] 
c [<ffffffff8123842b>] __lock_acquire+0x42b/0x4070 kernel/locking/lockdep.c:3294
RSP: 0018:ffff88019d71f5f0  EFLAGS: 00000006
RAX: 0000000000000008 RBX: ffff88019e2ce8c8 RCX: 000000000000000c
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88019e2ce8ec
RBP: ffff88019d71f7a0 R08: 0000000000000001 R09: 0000000000000001
R10: ffff88019e2ce000 R11: 0000000000000001 R12: 0000000000000413
R13: 0000000000000000 R14: ffff88019e2ce8b4 R15: 0000000000000004
FS:  00007f1bca4cd700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4a9674e000 CR3: 00000001c4395000 CR4: 00000000001606f0
Stack:
 ffff8801db221c00
c ffff8801db221ca0
c ffff88019d71f628
c 0000000000000046
c
 ffff8801d05d6080
c ffffffff84e99300
c 0000000000000003
c ffff88019d71f688
c
 ffff88019d71f670
c ffffffff81f1f87b
c ffffffff855f8e20
c 0000000000000001
c
Call Trace:
 [<ffffffff8123cae0>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff839ffbee>] __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:112 [inline]
 [<ffffffff839ffbee>] _raw_spin_lock_irqsave+0x4e/0x62 kernel/locking/spinlock.c:159
 [<ffffffff8122346b>] prepare_to_wait_event+0x6b/0x450 kernel/sched/wait.c:213
 [<ffffffff8190b23e>] request_wait_answer+0x22e/0x6e0 fs/fuse/dev.c:459
 [<ffffffff8190bd49>] __fuse_request_send+0x109/0x1b0 fs/fuse/dev.c:480
 [<ffffffff8190be4d>] fuse_request_send+0x5d/0x70 fs/fuse/dev.c:493
 [<ffffffff819160a4>] fuse_simple_request+0x2f4/0x660 fs/fuse/dev.c:551
 [<ffffffff81918d0a>] fuse_do_getattr+0x23a/0xb70 fs/fuse/dir.c:956
 [<ffffffff8191f061>] fuse_update_attributes+0x1b1/0x210 fs/fuse/dir.c:982
 [<ffffffff8191f187>] fuse_getattr+0xc7/0x120 fs/fuse/dir.c:1847
 [<ffffffff81583547>] vfs_getattr_nosec+0xd7/0x130 fs/stat.c:57
 [<ffffffff81583aa2>] vfs_getattr+0x32/0x50 fs/stat.c:72
 [<ffffffff81583c21>] vfs_fstatat+0xe1/0x170 fs/stat.c:110
 [<ffffffff81584db6>] vfs_stat fs/stat.c:123 [inline]
 [<ffffffff81584db6>] SYSC_newstat+0x86/0xf0 fs/stat.c:270
 [<ffffffff815851bd>] SyS_newstat+0x1d/0x30 fs/stat.c:266
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839ffcd3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c44 
c89 
cc0 
c83 
ce2 
c03 
c83 
ce0 
c01 
c41 
c09 
cf7 
cc1 
ce0 
c02 
c44 
c88 
c7b 
c21 
c83 
ce1 
cf8 
c09 
cd1 
c09 
cc1 
c45 
c85 
cc9 
c0f 
c95 
cc0 
c83 
ce1 
cf7 
cc1 
ce0 
c03 
c09 
cc1 
c88 
c4b 
c22 
c<0f> 
cb7 
c55 
c20 
c0f 
cb7 
c43 
c22 
cc1 
ce2 
c04 
c83 
ce0 
c0f 
c09 
cd0 
c48 
c89 
cfa 
c66 
c89 
c