Buffer I/O error on dev loop0, logical block 8, lost async page write
Buffer I/O error on dev loop0, logical block 9, lost async page write
buffer_io_error: 55 callbacks suppressed
Buffer I/O error on dev loop0, logical block 16, async page read
Buffer I/O error on dev loop0, logical block 16, async page read
INFO: task syz-executor0:3944 blocked for more than 120 seconds.
      Not tainted 4.9.92-g40a1830 #11
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D25824  3944   3903 0x20020004
 ffff8801d6ee0000 0000000000000000 ffff8801d68339c0 ffff8801d9b73000
 ffff8801db321b98 ffff8801d5776f80 ffffffff838a76cb 0000000041b58ab3
 ffffffff84193da8 00ffffff8123ac80 ffff8801db322468 ffff8801db322490
Call Trace:
 [<ffffffff838a8c6f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3551
 [<ffffffff838b4c2c>] schedule_timeout+0x56c/0x10b0 kernel/time/timer.c:1768
 [<ffffffff838a6e7e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5173
 [<ffffffff838aa0e9>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff838aa0e9>] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582
 [<ffffffff838a9952>] __wait_on_bit_lock+0xc2/0x1c0 kernel/sched/wait.c:421
 [<ffffffff8143202f>] __lock_page+0xff/0x160 mm/filemap.c:934
 [<ffffffff8145b8e3>] lock_page include/linux/pagemap.h:454 [inline]
 [<ffffffff8145b8e3>] write_cache_pages+0x833/0xec0 mm/page-writeback.c:2214
 [<ffffffff8145c04a>] generic_writepages+0xda/0x150 mm/page-writeback.c:2333
 [<ffffffff8162ab4d>] blkdev_writepages+0x1d/0x30 fs/block_dev.c:1764
 [<ffffffff8145ea0d>] do_writepages+0xed/0x1c0 mm/page-writeback.c:2347
 [<ffffffff8143a5b3>] __filemap_fdatawrite_range+0x1b3/0x250 mm/filemap.c:390
 [<ffffffff8143a869>] filemap_write_and_wait_range+0x59/0xb0 mm/filemap.c:580
 [<ffffffff81629e96>] blkdev_fsync+0x66/0xb0 fs/block_dev.c:369
 [<ffffffff816157ea>] vfs_fsync_range+0x10a/0x250 fs/sync.c:195
 [<ffffffff8162ca66>] generic_write_sync include/linux/fs.h:2590 [inline]
 [<ffffffff8162ca66>] blkdev_write_iter+0x2a6/0x380 fs/block_dev.c:1720
 [<ffffffff8156d500>] vfs_iter_write+0x2e0/0x450 fs/read_write.c:390
 [<ffffffff81612765>] iter_file_splice_write+0x5b5/0xb60 fs/splice.c:768
 [<ffffffff8160d5a5>] do_splice_from fs/splice.c:870 [inline]
 [<ffffffff8160d5a5>] direct_splice_actor+0x125/0x180 fs/splice.c:1037
 [<ffffffff8160eb6c>] splice_direct_to_actor+0x2cc/0x800 fs/splice.c:992
 [<ffffffff8160f247>] do_splice_direct+0x1a7/0x270 fs/splice.c:1080
 [<ffffffff8157221b>] do_sendfile+0x54b/0xd30 fs/read_write.c:1393
 [<ffffffff815742d1>] C_SYSC_sendfile fs/read_write.c:1469 [inline]
 [<ffffffff815742d1>] compat_SyS_sendfile+0xd1/0x160 fs/read_write.c:1458
 [<ffffffff81006f95>] do_syscall_32_irqs_on arch/x86/entry/common.c:325 [inline]
 [<ffffffff81006f95>] do_fast_syscall_32+0x2f5/0x870 arch/x86/entry/common.c:387
 [<ffffffff838b9c90>] entry_SYSENTER_compat+0x90/0xa2 arch/x86/entry/entry_64_compat.S:137

Showing all locks held in the system:
2 locks held by khungtaskd/515:
 #0:  (rcu_read_lock){......}, at: [<ffffffff813722b5>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff813722b5>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81236de0>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
3 locks held by kworker/u4:3/1805:
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118b0d2>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118b0d2>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118b0d2>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118b0d2>] process_one_work+0x6f2/0x1610 kernel/workqueue.c:2085
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff8118b10c>] process_one_work+0x72c/0x1610 kernel/workqueue.c:2089
 #2:  (&type->s_umount_key#29){.+.+..}, at: [<ffffffff815792b0>] trylock_super+0x20/0x100 fs/super.c:393
1 lock held by rsyslogd/3659:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d316f>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3755:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b67a2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8200a8f4>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133

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

NMI backtrace for cpu 0
CPU: 0 PID: 515 Comm: khungtaskd Not tainted 4.9.92-g40a1830 #11
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8467d00 ffffffff81d95109 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810bb8f0 ffff8801d8467d38
 ffffffff81da025d 0000000000000000 0000000000000000 ffff8801d6ee0418
Call Trace:
 [<ffffffff81d95109>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d95109>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81da025d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81da0397>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bb9e4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81372880>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81372880>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81372880>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81372880>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119c0dd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b875c>] 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: 0 Comm: swapper/1 Not tainted 4.9.92-g40a1830 #11
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801d9b73000 task.stack: ffff8801d9b88000
RIP: 0010:[<ffffffff8123b542>] 
c [<ffffffff8123b542>] __lock_acquire+0x8c2/0x3640 kernel/locking/lockdep.c:3349
RSP: 0018:ffff8801d9b8fac0  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8801d9b738b0 RCX: 1ffff1003b36e71a
RDX: ffff8801d9b738a8 RSI: 000000006e84b7f3 RDI: ffffffff84d0c298
RBP: ffff8801d9b8fc78 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: ffff8801d9b73000 R12: ffffffff84d0c288
R13: 00000000fff7565d R14: 643e07b86e84b7f3 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c42044b038 CR3: 00000001ca1a6000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801d9b738a8
c 0000000000000046
c ffff8801d9b73000
c ffffffff844ddde0
c
 ffff8801d71a4a80
c 0000000000000001
c ffff8801d9b8fb18
c 0000000000000046
c
 0000000000000003
c ffff8801db321c20
c ffff8801d71a4a70
c ffff8801d9b8fb30
c
Call Trace:
 [<ffffffff8123ecfe>] lock_acquire+0x12e/0x410 kernel/locking/lockdep.c:3756
 [<ffffffff811ba095>] finish_lock_switch kernel/sched/sched.h:1210 [inline]
 [<ffffffff811ba095>] finish_task_switch+0x1e5/0x630 kernel/sched/core.c:2819
 [<ffffffff838a76d3>] context_switch kernel/sched/core.c:2952 [inline]
 [<ffffffff838a76d3>] __schedule+0x683/0x1ba0 kernel/sched/core.c:3496
 [<ffffffff838a8c6f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3551
 [<ffffffff838a95f3>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3584
 [<ffffffff81225697>] cpu_idle_loop kernel/sched/idle.c:274 [inline]
 [<ffffffff81225697>] cpu_startup_entry+0x297/0x380 kernel/sched/idle.c:303
 [<ffffffff810b08f3>] start_secondary+0x303/0x3e0 arch/x86/kernel/smpboot.c:254
Code: 
c00 
cfc 
cff 
cdf 
c48 
cc1 
cea 
c03 
c80 
c3c 
c02 
c00 
c0f 
c85 
c91 
c28 
c00 
c00 
c48 
c8b 
c94 
c24 
c90 
c00 
c00 
c00 
c4d 
c89 
cb3 
ca0 
c08 
c00 
c00 
c48 
cb8 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c<48> 
cc1 
cea 
c03 
c0f 
cb6 
c04 
c02 
c84 
cc0 
c74 
c08 
c3c 
c03 
c0f 
c8e 
c42 
c28 
c00 
c00 
c41 
c