INFO: task syz-executor0:5846 blocked for more than 120 seconds.
      Not tainted 4.9.78-ge9dabe6 #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D29680  5846   3396 0x00000004
 ffff8801c25d3000 ffff8801c19eef40 ffff8801cd830000 ffff8801c262e000
 ffff8801db221b98 ffff8801c19c78e0 ffffffff838a1bbb 0000000041b58ab3
 ffffffff84193238 00ffffff8123be20 ffff8801db222468 ffff8801db222490
Call Trace:
 [<ffffffff838a315f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838af2bc>] schedule_timeout+0x56c/0x10b0 kernel/time/timer.c:1768
 [<ffffffff838a136e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5172
 [<ffffffff838a45d9>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff838a45d9>] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582
 [<ffffffff838a3e42>] __wait_on_bit_lock+0xc2/0x1c0 kernel/sched/wait.c:421
 [<ffffffff81432cef>] __lock_page+0xff/0x160 mm/filemap.c:934
 [<ffffffff81437e76>] lock_page include/linux/pagemap.h:454 [inline]
 [<ffffffff81437e76>] pagecache_get_page+0x436/0x710 mm/filemap.c:1216
 [<ffffffff8146c0e5>] find_lock_page include/linux/pagemap.h:284 [inline]
 [<ffffffff8146c0e5>] truncate_inode_pages_range+0x655/0x12c0 mm/truncate.c:320
 [<ffffffff8162bb91>] blkdev_fallocate+0x221/0x440 fs/block_dev.c:1817
 [<ffffffff815656ea>] vfs_fallocate+0x33a/0x5f0 fs/open.c:329
 [<ffffffff81568713>] SYSC_fallocate fs/open.c:352 [inline]
 [<ffffffff81568713>] SyS_fallocate+0x53/0x90 fs/open.c:346
 [<ffffffff838b2c6e>] entry_SYSCALL_64_fastpath+0x29/0xe8

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372df5>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372df5>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81237f80>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3179:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d32ef>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3306:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b0e32>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<ffffffff820096f4>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor0/5846:
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff81565691>] sb_start_write include/linux/fs.h:1554 [inline]
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff81565691>] vfs_fallocate+0x2e1/0x5f0 fs/open.c:328
1 lock held by syz-executor0/5855:
 #0:  (&lo->lo_ctl_mutex/1){+.+.+.}, at: [<ffffffff824b614f>] lo_ioctl+0x8f/0x1990 drivers/block/loop.c:1337

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

NMI backtrace for cpu 1
CPU: 1 PID: 514 Comm: khungtaskd Not tainted 4.9.78-ge9dabe6 #19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d8bb7d00 ffffffff81d943a9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810bac10 ffff8801d8bb7d38
 ffffffff81d9f4cd 0000000000000001 0000000000000000 ffff8801c1ffe418
Call Trace:
 [<ffffffff81d943a9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d943a9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81d9f4cd>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81d9f607>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bad04>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff813733c0>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff813733c0>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813733c0>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813733c0>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119a72d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b2fdc>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:477
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff838b18a6