INFO: task syz-executor5:32573 blocked for more than 120 seconds.
      Not tainted 4.9.107-gdb2c520 #49
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D29464 32573   3682 0x00000004
 ffff8801c1620000 0000000000000000 ffff8801d51f4a80 ffff8801d9a6b000
 ffff8801db321c18 ffff8801ceca7aa0 ffffffff839e8c1d 1ffff10039d94f48
 ffffffff85542240 0000000041b58ab3 00ffffff843c2388 ffff8801db3224e8
Call Trace:
 [<ffffffff839ea21f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3557
 [<ffffffff839f6631>] schedule_timeout+0x861/0xf70 kernel/time/timer.c:1768
 [<ffffffff839e83fa>] io_schedule_timeout+0x1ba/0x390 kernel/sched/core.c:5180
 [<ffffffff839ebb53>] do_wait_for_common kernel/sched/completion.c:75 [inline]
 [<ffffffff839ebb53>] __wait_for_common kernel/sched/completion.c:93 [inline]
 [<ffffffff839ebb53>] wait_for_common_io kernel/sched/completion.c:107 [inline]
 [<ffffffff839ebb53>] wait_for_completion_io+0x203/0x2e0 kernel/sched/completion.c:155
 [<ffffffff81dfb5a2>] submit_bio_wait+0x112/0x180 block/bio.c:885
 [<ffffffff81e2dcf2>] blkdev_issue_flush+0x152/0x220 block/blk-flush.c:518
 [<ffffffff8162f005>] blkdev_fsync+0x85/0xb0 fs/block_dev.c:378
 [<ffffffff8161a60c>] vfs_fsync_range+0x10c/0x260 fs/sync.c:195
 [<ffffffff8161a7d2>] vfs_fsync fs/sync.c:209 [inline]
 [<ffffffff8161a7d2>] do_fsync+0x42/0xb0 fs/sync.c:219
 [<ffffffff8161af79>] SYSC_fdatasync fs/sync.c:233 [inline]
 [<ffffffff8161af79>] SyS_fdatasync+0x19/0x20 fs/sync.c:231
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] 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: [<ffffffff8136662c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136662c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81425cb7>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3526:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d7fac>] __fdget_pos+0xac/0xd0 fs/file.c:781
2 locks held by getty/3622:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff839f7cc2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff8211fc62>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2133

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

NMI backtrace for cpu 0
CPU: 0 PID: 519 Comm: khungtaskd Not tainted 4.9.107-gdb2c520 #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d849fd08 ffffffff81eb3da9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810b96a0 ffff8801d849fd40
 ffffffff81ebf0a7 0000000000000000 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81eb3da9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb3da9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81ebf0a7>] nmi_cpu_backtrace.cold.2+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81ebf03a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff810b97a4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81366bc4>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81366bc4>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81366bc4>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81366bc4>] watchdog+0x6b4/0xa20 kernel/hung_task.c:239
 [<ffffffff8119d04d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff839f9cdc>] 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: 3524 Comm: rs:main Q:Reg Not tainted 4.9.107-gdb2c520 #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801cb73b000 task.stack: ffff8801c86a8000
RIP: 0010:[<ffffffff8135e98b>] 
c [<ffffffff8135e98b>] __write_once_size include/linux/compiler.h:272 [inline]
RIP: 0010:[<ffffffff8135e98b>] 
c [<ffffffff8135e98b>] __sanitizer_cov_trace_pc+0x4b/0x50 kernel/kcov.c:108
RSP: 0018:ffff8801c86afe20  EFLAGS: 00000293
RAX: ffff8801cb73b000 RBX: ffff8801c850ee01 RCX: ffff8801cb73b000
RDX: 0000000000000000 RSI: ffffffff815d7f9c RDI: ffff8801c850ee68
RBP: ffff8801c86afe20 R08: ffff8801cb73b8e8 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000001 R12: ffff8801c850ee00
R13: ffff8801c86affd0 R14: ffff8801cb73b000 R15: dffffc0000000000
FS:  00007fc830c2a700(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f62d3bda140 CR3: 00000001cb603000 CR4: 00000000001606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801c86afe40
c ffffffff815d7f9c
c 0000000000000002
c 1ffff100390d5fcd
c
 ffff8801c86afef0
c ffffffff8157669e
c ffff8801c850eef8
c 0000000000000287
c
 0000000001e46340
c 0000000041b58ab3
c ffffffff843d3a88
c ffffffff81576620
c
Call Trace:
 [<ffffffff815d7f9c>] __fdget_pos+0x9c/0xd0 fs/file.c:780
 [<ffffffff8157669e>] fdget_pos include/linux/file.h:66 [inline]
 [<ffffffff8157669e>] SYSC_write fs/read_write.c:599 [inline]
 [<ffffffff8157669e>] SyS_write+0x7e/0x1c0 fs/read_write.c:596
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f9b13>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
c8b 
c90 
c80 
c12 
c00 
c00 
c83 
cfa 
c02 
c75 
c20 
c48 
c8b 
c88 
c88 
c12 
c00 
c00 
c8b 
c80 
c84 
c12 
c00 
c00 
c48 
c8b 
c11 
c48 
c83 
cc2 
c01 
c48 
c39 
cd0 
c76 
c07 
c48 
c89 
c34 
cd1 
c48 
c89 
c11 
c<5d> 
cc3 
c0f 
c1f 
c00 
c55 
c48 
c89 
ce5 
c41 
c57 
c41 
c56 
c41 
c55 
c41 
c54 
c53 
c48 
c89 
cf3 
c