Buffer I/O error on dev loop0, logical block 64, async page read
kworker/dying (28) used greatest stack depth: 8328 bytes left
INFO: task syz-executor7:21311 blocked for more than 120 seconds.
      Not tainted 4.16.0-rc7+ #374
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D24104 21311   4530 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2862 [inline]
 __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
 schedule+0xf5/0x430 kernel/sched/core.c:3499
 io_schedule+0x1c/0x70 kernel/sched/core.c:5115
 wait_on_page_bit_common+0x4b3/0x770 mm/filemap.c:1099
 wait_on_page_bit mm/filemap.c:1132 [inline]
 wait_on_page_writeback include/linux/pagemap.h:546 [inline]
 __filemap_fdatawait_range+0x282/0x430 mm/filemap.c:533
 file_fdatawait_range+0x47/0x60 mm/filemap.c:581
 SYSC_sync_file_range fs/sync.c:341 [inline]
 SyS_sync_file_range+0x1e3/0x210 fs/sync.c:283
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454e79
RSP: 002b:00007fcd9fb5fc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000115
RAX: ffffffffffffffda RBX: 00007fcd9fb606d4 RCX: 0000000000454e79
RDX: 000000007fffffff RSI: 0000000000000002 RDI: 0000000000000013
RBP: 000000000072bf58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000007 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000064c R14: 00000000006fb7c0 R15: 0000000000000001

Showing all locks held in the system:
3 locks held by kworker/u4:3/83:
 #0:  ((wq_completion)"writeback"){+.+.}, at: [<000000006c1c6c3e>] work_static include/linux/workqueue.h:198 [inline]
 #0:  ((wq_completion)"writeback"){+.+.}, at: [<000000006c1c6c3e>] set_work_data kernel/workqueue.c:619 [inline]
 #0:  ((wq_completion)"writeback"){+.+.}, at: [<000000006c1c6c3e>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
 #0:  ((wq_completion)"writeback"){+.+.}, at: [<000000006c1c6c3e>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084
 #1:  ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [<000000008e0384b2>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088
 #2:  (&type->s_umount_key#34){++++}, at: [<0000000029d1b097>] trylock_super+0x20/0x100 fs/super.c:395
2 locks held by khungtaskd/873:
 #0:  (rcu_read_lock){....}, at: [<0000000012764776>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
 #0:  (rcu_read_lock){....}, at: [<0000000012764776>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249
 #1:  (tasklist_lock){.+.+}, at: [<0000000026d0f384>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470
1 lock held by rsyslogd/4364:
 #0:  (&f->f_pos_lock){+.+.}, at: [<0000000048c7df74>] __fdget_pos+0x12b/0x190 fs/file.c:765
2 locks held by getty/4454:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000d4d98825>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000018f26416>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4455:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000d4d98825>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000018f26416>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4456:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000d4d98825>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000018f26416>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4457:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000d4d98825>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000018f26416>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4458:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000d4d98825>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000018f26416>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4459:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000d4d98825>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000018f26416>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131
2 locks held by getty/4460:
 #0:  (&tty->ldisc_sem){++++}, at: [<00000000d4d98825>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<0000000018f26416>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131

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

NMI backtrace for cpu 1
CPU: 1 PID: 873 Comm: khungtaskd Not tainted 4.16.0-rc7+ #374
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x24d lib/dump_stack.c:53
 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x123/0x180 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline]
 check_hung_task kernel/hung_task.c:132 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
 watchdog+0x90c/0xd60 kernel/hung_task.c:249
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54