INFO: task syz-executor6:5134 blocked for more than 120 seconds.
      Not tainted 4.9.67-gf26d3c7 #106
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor6   D29712  5134   3536 0x00000004
 ffff8801d5b50000 0000000000000000 ffff8801ce4b9a40 ffff8801d5b51800
 ffff8801db221418 ffff8801d5b5faa0 ffffffff838981cb ffffffff81239470
 ffff8801d5b5fb58 00ffffff81d29272 ffff8801db221ce8 ffff8801db221d10
Call Trace:
 [<ffffffff8389976f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838a59a3>] schedule_timeout+0x643/0x1220 kernel/time/timer.c:1770
 [<ffffffff8389797e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5172
 [<ffffffff8389b0de>] do_wait_for_common kernel/sched/completion.c:75 [inline]
 [<ffffffff8389b0de>] __wait_for_common kernel/sched/completion.c:93 [inline]
 [<ffffffff8389b0de>] wait_for_common_io kernel/sched/completion.c:107 [inline]
 [<ffffffff8389b0de>] wait_for_completion_io+0x20e/0x2e0 kernel/sched/completion.c:155
 [<ffffffff81cd6ebb>] submit_bio_wait+0x11b/0x180 block/bio.c:885
 [<ffffffff81d1d66e>] __blkdev_issue_zeroout block/blk-lib.c:239 [inline]
 [<ffffffff81d1d66e>] blkdev_issue_zeroout+0x2de/0x4a0 block/blk-lib.c:281
 [<ffffffff8162819f>] blkdev_fallocate+0x25f/0x440 fs/block_dev.c:1822
 [<ffffffff81561d4a>] vfs_fallocate+0x33a/0x5f0 fs/open.c:329
 [<ffffffff81564d73>] SYSC_fallocate fs/open.c:352 [inline]
 [<ffffffff81564d73>] SyS_fallocate+0x53/0x90 fs/open.c:346
 [<ffffffff838a9985>] entry_SYSCALL_64_fastpath+0x23/0xc6

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136fe05>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8136fe05>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff812355d0>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3149:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815cf8df>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3240:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838a7b92>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff82001d24>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor6/5134:
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff81561cf1>] sb_start_write include/linux/fs.h:1554 [inline]
 #0:  (sb_writers){.+.+.+}, at: [<ffffffff81561cf1>] vfs_fallocate+0x2e1/0x5f0 fs/open.c:328

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

NMI backtrace for cpu 1
CPU: 1 PID: 514 Comm: khungtaskd Not tainted 4.9.67-gf26d3c7 #106
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d890fd00 ffffffff81d906e9 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff810ba170 ffff8801d890fd38
 ffffffff81d9b80d 0000000000000001 0000000000000000 ffff8801d91f6418
Call Trace:
 [<ffffffff81d906e9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d906e9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81d9b80d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81d9b947>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810ba264>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff813703d0>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff813703d0>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813703d0>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813703d0>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff811985ad>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838a9c2a>] ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:433
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff838a8606