INFO: task syz-executor3:16319 blocked for more than 120 seconds.
      Not tainted 4.9.77-g033d019 #14
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor3   D28920 16319   5071 0x00000004
 ffff8801ce6eb000 ffff8801ce781a40 ffff8801ce5c5a40 ffff8801ce53e000
 ffff8801db321b98 ffff8801c9127b00 ffffffff838a1adb 0000000041b58ab3
 ffffffff84193178 00ffffff8123bda0 ffff8801db322468 ffff8801db322490
Call Trace:
 [<ffffffff838a307f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838af1dc>] schedule_timeout+0x56c/0x10b0 kernel/time/timer.c:1768
 [<ffffffff838a128e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5172
 [<ffffffff838a49ee>] do_wait_for_common kernel/sched/completion.c:75 [inline]
 [<ffffffff838a49ee>] __wait_for_common kernel/sched/completion.c:93 [inline]
 [<ffffffff838a49ee>] wait_for_common_io kernel/sched/completion.c:107 [inline]
 [<ffffffff838a49ee>] wait_for_completion_io+0x20e/0x2e0 kernel/sched/completion.c:155
 [<ffffffff81cdaabb>] submit_bio_wait+0x11b/0x180 block/bio.c:885
 [<ffffffff81d0dc67>] blkdev_issue_flush+0x157/0x220 block/blk-flush.c:518
 [<ffffffff81629ed5>] blkdev_fsync+0x85/0xb0 fs/block_dev.c:378
 [<ffffffff8161583a>] vfs_fsync_range+0x10a/0x250 fs/sync.c:195
 [<ffffffff816159f2>] vfs_fsync fs/sync.c:209 [inline]
 [<ffffffff816159f2>] do_fsync+0x42/0xb0 fs/sync.c:219
 [<ffffffff81616199>] SYSC_fdatasync fs/sync.c:233 [inline]
 [<ffffffff81616199>] SyS_fdatasync+0x19/0x20 fs/sync.c:231
 [<ffffffff838b2b6e>] entry_SYSCALL_64_fastpath+0x29/0xe8

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372d85>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372d85>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81237f00>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
2 locks held by getty/3306:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b0d52>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff82009514>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133

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

NMI backtrace for cpu 0
CPU: 0 PID: 514 Comm: khungtaskd Not tainted 4.9.77-g033d019 #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d895fd00 ffffffff81d941c9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810babe0 ffff8801d895fd38
 ffffffff81d9f2ed 0000000000000000 0000000000000000 ffff8801cde18418
Call Trace:
 [<ffffffff81d941c9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d941c9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81d9f2ed>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81d9f427>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bacd4>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81373350>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81373350>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81373350>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81373350>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119a6fd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b2ea9>] ret_from_fork+0x59/0x70 arch/x86/entry/entry_64.S:466
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.9.77-g033d019 #14
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801da3d3000 task.stack: ffff8801da3e8000
RIP: 0010:[<ffffffff8128cd72>] 
c [<ffffffff8128cd72>] atomic_inc arch/x86/include/asm/atomic.h:91 [inline]
RIP: 0010:[<ffffffff8128cd72>] 
c [<ffffffff8128cd72>] rcu_eqs_exit_common.isra.44+0x42/0x60 kernel/rcu/tree.c:838
RSP: 0018:ffff8801db307f88  EFLAGS: 00000006
RAX: 0000000000000001 RBX: ffff8801db31a690 RCX: 1ffffffff083fe7d
RDX: dffffc0000000000 RSI: ffffffff83c18780 RDI: ffffffff841ff3e8
RBP: ffff8801db307f98 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff84a36978 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f36176709b8 CR3: 00000001cf17a000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801db307f98
c ffff8801db31a690
c ffff8801db307fb8
c ffffffff81296633
c
 0000000000000000
c ffffffff84a27868
c ffff8801db307fd0
c ffffffff8114699a
c
 ffffffff84a27868
c ffff8801db307fe8
c ffffffff838b734a
c ffffffff84a27868
c
Call Trace:
 <IRQ> 
d [<ffffffff81296633>] rcu_irq_enter+0xc3/0x120 kernel/rcu/tree.c:952
 [<ffffffff8114699a>] irq_enter+0xa/0xd0 kernel/softirq.c:338
 [<ffffffff838b734a>] smp_reschedule_interrupt+0xa/0x80 arch/x86/kernel/smp.c:264
 [<ffffffff838b4fc0>] reschedule_interrupt+0xa0/0xb0 arch/x86/entry/entry_64.S:764
 <EOI> 
d [<ffffffff838b17c6>] ? native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:53
 [<ffffffff838b0df5>] arch_safe_halt arch/x86/include/asm/paravirt.h:103 [inline]
 [<ffffffff838b0df5>] default_idle+0x55/0x360 arch/x86/kernel/process.c:295
 [<ffffffff8106bc9a>] arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:286
 [<ffffffff838b1c06>] default_idle_call+0x36/0x60 kernel/sched/idle.c:97
 [<ffffffff81226500>] cpuidle_idle_call kernel/sched/idle.c:155 [inline]
 [<ffffffff81226500>] cpu_idle_loop kernel/sched/idle.c:248 [inline]
 [<ffffffff81226500>] cpu_startup_entry+0x2b0/0x380 kernel/sched/idle.c:303
 [<ffffffff810afc93>] start_secondary+0x303/0x3e0 arch/x86/kernel/smpboot.c:254
Code: 
c00 
c00 
c00 
c00 
c00 
cfc 
cff 
cdf 
c89 
cc0 
c48 
c8d 
c3c 
cc5 
ce0 
cf3 
c1f 
c84 
c48 
c89 
cf9 
c48 
cc1 
ce9 
c03 
c80 
c3c 
c11 
c00 
c75 
c13 
c48 
c03 
c1c 
cc5 
ce0 
cf3 
c1f 
c84 
cf0 
cff 
c43 
c0c 
c<48> 
c83 
cc4 
c08 
c5b 
c5d 
cc3 
c48 
c89 
c45 
cf0 
ce8 
c7e 
c14 
c2b 
c00 
c48 
c8b 
c45 
cf0 
ceb 
c