INFO: task syz-executor0:9795 blocked for more than 120 seconds.
      Not tainted 4.9.80-g550c01d #37
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D29040  9795   3889 0x20020004
 ffff8801cc363000 ffff8801ce4af9c0 ffff8801beb09f80 ffff8801b3326000
 ffff8801db321b98 ffff8801bd3275f0 ffffffff838a23db 0000000041b58ab3
 ffffffff84193128 00ffffff8123be80 ffff8801db322468 ffff8801db322490
Call Trace:
 [<ffffffff838a397f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838afadc>] schedule_timeout+0x56c/0x10b0 kernel/time/timer.c:1768
 [<ffffffff838a1b8e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5172
 [<ffffffff838a4df9>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff838a4df9>] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582
 [<ffffffff838a4662>] __wait_on_bit_lock+0xc2/0x1c0 kernel/sched/wait.c:421
 [<ffffffff81432ddf>] __lock_page+0xff/0x160 mm/filemap.c:934
 [<ffffffff81437f66>] lock_page include/linux/pagemap.h:454 [inline]
 [<ffffffff81437f66>] pagecache_get_page+0x436/0x710 mm/filemap.c:1216
 [<ffffffff81438c2c>] grab_cache_page_write_begin+0x6c/0xa0 mm/filemap.c:2685
 [<ffffffff816266da>] block_write_begin+0x3a/0x190 fs/buffer.c:2093
 [<ffffffff8162b35c>] blkdev_write_begin+0x3c/0x50 fs/block_dev.c:330
 [<ffffffff81434361>] generic_perform_write+0x261/0x500 mm/filemap.c:2741
 [<ffffffff8143beb8>] __generic_file_write_iter+0x348/0x570 mm/filemap.c:2866
 [<ffffffff8162d1fc>] blkdev_write_iter+0x1bc/0x380 fs/block_dev.c:1718
 [<ffffffff8156e89f>] new_sync_write fs/read_write.c:499 [inline]
 [<ffffffff8156e89f>] __vfs_write+0x4bf/0x680 fs/read_write.c:512
 [<ffffffff815701c9>] vfs_write+0x189/0x530 fs/read_write.c:560
 [<ffffffff81573cb9>] SYSC_write fs/read_write.c:607 [inline]
 [<ffffffff81573cb9>] SyS_write+0xd9/0x1b0 fs/read_write.c:599
 [<ffffffff81006fc7>] do_syscall_32_irqs_on arch/x86/entry/common.c:322 [inline]
 [<ffffffff81006fc7>] do_fast_syscall_32+0x2f7/0x890 arch/x86/entry/common.c:384
 [<ffffffff838b4d34>] entry_SYSENTER_compat+0x74/0x83 arch/x86/entry/entry_64_compat.S:127

Showing all locks held in the system:
2 locks held by khungtaskd/515:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372ed5>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372ed5>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81237fe0>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3658:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d3a5f>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3786:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b1652>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff82009fa4>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by blkid/7097:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162db6c>] __blkdev_put+0xbc/0x7e0 fs/block_dev.c:1579

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

NMI backtrace for cpu 0
CPU: 0 PID: 515 Comm: khungtaskd Not tainted 4.9.80-g550c01d #37
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8007d00 ffffffff81d94b69 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810bac60 ffff8801d8007d38
 ffffffff81d9fc8d 0000000000000000 0000000000000000 ffff8801bd2a3418
Call Trace:
 [<ffffffff81d94b69>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d94b69>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81d9fc8d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81d9fdc7>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bad54>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff813734a0>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff813734a0>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813734a0>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813734a0>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119a73d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b37dc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:477
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff838b20c6