FAT-fs (loop4): Unrecognized mount option "

" or missing value
FAT-fs (loop3): bogus number of reserved sectors
FAT-fs (loop3): Can't find a valid FAT filesystem
FAT-fs (loop3): Unrecognized mount option "€" or missing value
INFO: task kworker/u4:3:30645 blocked for more than 120 seconds.
      Not tainted 4.9.111-g03c70fe #5
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:3    D25736 30645      2 0x00000000
Workqueue: events_unbound flush_to_ldisc
 ffff88019bc36000 0000000000000000 ffff88019bec9a40 ffff8801d9584800
 ffff8801db221c18 ffff88019501f8c8 ffffffff839e7ded ffff88019bc368c8
 ffffed0033786d18 ffff88019bc36000 00fffc0000000000 ffff8801db2224e8
Call Trace:
 [<ffffffff839e93ef>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839e9d73>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3590
 [<ffffffff839ee1f6>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff839ee1f6>] mutex_lock_nested+0x326/0x870 kernel/locking/mutex.c:621
 [<ffffffff8211bdd0>] commit_echoes+0x120/0x1b0 drivers/tty/n_tty.c:764
 [<ffffffff82124a28>] n_tty_receive_char_fast drivers/tty/n_tty.c:1418 [inline]
 [<ffffffff82124a28>] n_tty_receive_buf_fast drivers/tty/n_tty.c:1578 [inline]
 [<ffffffff82124a28>] __receive_buf drivers/tty/n_tty.c:1613 [inline]
 [<ffffffff82124a28>] n_tty_receive_buf_common+0x1878/0x2300 drivers/tty/n_tty.c:1711
 [<ffffffff821254e3>] n_tty_receive_buf2+0x33/0x40 drivers/tty/n_tty.c:1746
 [<ffffffff8212afdf>] tty_ldisc_receive_buf+0xaf/0x190 drivers/tty/tty_buffer.c:455
 [<ffffffff8212bfe3>] receive_buf drivers/tty/tty_buffer.c:474 [inline]
 [<ffffffff8212bfe3>] flush_to_ldisc+0x253/0x370 drivers/tty/tty_buffer.c:533
 [<ffffffff8118d131>] process_one_work+0x7e1/0x1500 kernel/workqueue.c:2092
 [<ffffffff8118df26>] worker_thread+0xd6/0x10a0 kernel/workqueue.c:2226
 [<ffffffff8119d05d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f8e9c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373

Showing all locks held in the system:
2 locks held by khungtaskd/519:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813666fc>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813666fc>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81425d87>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/3775:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f6e92>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8211e602>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133
6 locks held by kworker/u4:3/30645:
 #0:  ("events_unbound"){.+.+.+}, at: [<ffffffff8118d03e>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("events_unbound"){.+.+.+}, at: [<ffffffff8118d03e>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("events_unbound"){.+.+.+}, at: [<ffffffff8118d03e>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("events_unbound"){.+.+.+}, at: [<ffffffff8118d03e>] process_one_work+0x6ee/0x1500 kernel/workqueue.c:2085
 #1:  ((&buf->work)){+.+...}, at: [<ffffffff8118d078>] process_one_work+0x728/0x1500 kernel/workqueue.c:2089
 #2:  (&tty->ldisc_sem){++++++}, at: [<ffffffff821297b0>] tty_ldisc_ref+0x20/0x80 drivers/tty/tty_ldisc.c:296
 #3:  (&port->buf.lock/1){+.+...}, at: [<ffffffff8212be16>] flush_to_ldisc+0x86/0x370 drivers/tty/tty_buffer.c:505
 #4:  (&o_tty->termios_rwsem/1){++++..}, at: [<ffffffff8211ca19>] isig+0x3d9/0x4c0 drivers/tty/n_tty.c:1121
 #5:  (&ldata->output_lock){+.+...}, at: [<ffffffff8211bdd0>] commit_echoes+0x120/0x1b0 drivers/tty/n_tty.c:764
3 locks held by syz-executor0/22334:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f6e92>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&o_tty->termios_rwsem/1){++++..}, at: [<ffffffff8212323b>] n_tty_receive_buf_common+0x8b/0x2300 drivers/tty/n_tty.c:1674
 #2:  (&ldata->output_lock){+.+...}, at: [<ffffffff8211bdd0>] commit_echoes+0x120/0x1b0 drivers/tty/n_tty.c:764

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

NMI backtrace for cpu 1
CPU: 1 PID: 519 Comm: khungtaskd Not tainted 4.9.111-g03c70fe #5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d844fd08 ffffffff81eb2729 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810b9af0 ffff8801d844fd40
 ffffffff81ebda27 0000000000000001 0000000000000000 0000000000000002
Call Trace:
 [<ffffffff81eb2729>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb2729>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebda27>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebd9ba>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b9bf4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81366c94>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366c94>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366c94>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366c94>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d05d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f8e9c>] 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: 22264 Comm: syz-executor0 Not tainted 4.9.111-g03c70fe #5
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801bf970000 task.stack: ffff8801b70f0000
RIP: 0010:[<ffffffff8127bf03>] 
c [<ffffffff8127bf03>] debug_lockdep_rcu_enabled+0x53/0x90 kernel/rcu/update.c:264
RSP: 0018:ffff8801db207c48  EFLAGS: 00000802
RAX: dffffc0000000000 RBX: ffffffff85c893e0 RCX: 1ffff10034d36ef1
RDX: 1ffffffff090e120 RSI: 0000000000000001 RDI: ffffffff84870900
RBP: ffff8801db207c48 R08: ffff8801bf970988 R09: 0000000000000001
R10: 0000000000000000 R11: 1ffff10037f2e12c R12: ffffffff85c893c8
R13: ffff8801bf970000 R14: ffff8801a89cb448 R15: dffffc0000000000
FS:  00007f408712f700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa96ef1d140 CR3: 00000001d38b7000 CR4: 00000000001606f0
DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000020000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Stack:
 ffff8801db207d00
c ffffffff8123b646
c 0000000000000046
c ffff8801bf970000
c
 0000000000000000
c 0000000000000000
c 0000000000000000
c ffff8801db207cf8
c
 0000000000000046
c 0000000000000000
c ffffffff81f1b107
c ffffffff00000000
c
Call Trace:
 <IRQ> 
d [<ffffffff8123b646>] trace_lock_release include/trace/events/lock.h:57 [inline]
 <IRQ> 
d [<ffffffff8123b646>] lock_release+0x746/0xb80 kernel/locking/lockdep.c:3774
 [<ffffffff839f83af>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:160 [inline]
 [<ffffffff839f83af>] _raw_spin_unlock_irqrestore+0x1f/0x70 kernel/locking/spinlock.c:191
 [<ffffffff81f1b224>] debug_object_deactivate+0x214/0x340 lib/debugobjects.c:503
 [<ffffffff812a45c2>] debug_hrtimer_deactivate kernel/time/hrtimer.c:403 [inline]
 [<ffffffff812a45c2>] debug_deactivate kernel/time/hrtimer.c:450 [inline]
 [<ffffffff812a45c2>] __run_hrtimer kernel/time/hrtimer.c:1224 [inline]
 [<ffffffff812a45c2>] __hrtimer_run_queues+0x222/0xe50 kernel/time/hrtimer.c:1319
 [<ffffffff812a5c51>] hrtimer_interrupt+0x1b1/0x430 kernel/time/hrtimer.c:1353
 [<ffffffff810b22a4>] local_apic_timer_interrupt+0x74/0xa0 arch/x86/kernel/apic/apic.c:935
 [<ffffffff839fe49c>] smp_apic_timer_interrupt+0x7c/0xa0 arch/x86/kernel/apic/apic.c:959
 [<ffffffff839fa630>] apic_timer_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:648
 <EOI> 
d [<ffffffff8211a4af>] ? echo_buf drivers/tty/n_tty.c:146 [inline]
 <EOI> 
d [<ffffffff8211a4af>] ? __process_echoes+0x5cf/0x780 drivers/tty/n_tty.c:734
 [<ffffffff82123ee4>] flush_echoes drivers/tty/n_tty.c:801 [inline]
 [<ffffffff82123ee4>] __receive_buf drivers/tty/n_tty.c:1617 [inline]
 [<ffffffff82123ee4>] n_tty_receive_buf_common+0xd34/0x2300 drivers/tty/n_tty.c:1711
 [<ffffffff82125520>] n_tty_receive_buf+0x30/0x40 drivers/tty/n_tty.c:1740
 [<ffffffff8211593f>] tiocsti drivers/tty/tty_io.c:2314 [inline]
 [<ffffffff8211593f>] tty_ioctl+0xc8f/0x2270 drivers/tty/tty_io.c:2905
 [<ffffffff815b2c6c>] vfs_ioctl fs/ioctl.c:43 [inline]
 [<ffffffff815b2c6c>] file_ioctl fs/ioctl.c:493 [inline]
 [<ffffffff815b2c6c>] do_vfs_ioctl+0x1ac/0x11a0 fs/ioctl.c:677
 [<ffffffff815b3cef>] SYSC_ioctl fs/ioctl.c:694 [inline]
 [<ffffffff815b3cef>] SyS_ioctl+0x8f/0xc0 fs/ioctl.c:685
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f8cd3>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c03 
c38 
cd0 
c7c 
c04 
c84 
cd2 
c75 
c4c 
c8b 
c15 
cdd 
c27 
c9e 
c03 
c85 
cd2 
c74 
c3e 
c48 
cc7 
cc7 
c00 
c09 
c87 
c84 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c48 
c89 
cfa 
c48 
cc1 
cea 
c03 
c<0f> 
cb6 
c14 
c02 
c48 
c89 
cf8 
c83 
ce0 
c07 
c83 
cc0 
c03 
c38 
cd0 
c7c 
c04 
c84 
cd2 
c75 
c1c 
c