INFO: task syz-executor7:2296 blocked for more than 140 seconds.
      Not tainted 4.9.124+ #33
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor7   D27640  2296      1 0x00000004
 ffff8801bbfe97c0 ffff88019e16e880 ffff8801d6bfe300 ffff8801d3b0c740
 ffff8801db6210d8 ffff8801b0127b50 ffffffff8277cf52 ffff8801b0127b28
 ffffffff81201f37 0000000000000000 00ff8801bbfea068 ffff8801db6219b0
Call Trace:
 [<ffffffff8277e47f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3553
 [<ffffffff82787526>] __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:526 [inline]
 [<ffffffff82787526>] rwsem_down_write_failed+0x336/0x5a0 kernel/locking/rwsem-xadd.c:555
 [<ffffffff81b26c67>] call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:105
 [<ffffffff827863bc>] __down_write arch/x86/include/asm/rwsem.h:125 [inline]
 [<ffffffff827863bc>] down_write+0x5c/0xa0 kernel/locking/rwsem.c:54
 [<ffffffff8185c600>] fuse_kill_sb_anon+0x50/0xb0 fs/fuse/inode.c:1206
 [<ffffffff815054f5>] deactivate_locked_super+0x75/0xd0 fs/super.c:310
 [<ffffffff815071d1>] deactivate_super+0x91/0xd0 fs/super.c:341
 [<ffffffff815641b2>] cleanup_mnt+0xb2/0x160 fs/namespace.c:1143
 [<ffffffff815642e6>] __cleanup_mnt+0x16/0x20 fs/namespace.c:1150
 [<ffffffff8113c37c>] task_work_run+0x10c/0x180 kernel/task_work.c:116
 [<ffffffff81003e49>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<ffffffff81003e49>] exit_to_usermode_loop+0x129/0x150 arch/x86/entry/common.c:161
 [<ffffffff8100570d>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff8100570d>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff8100570d>] do_syscall_64+0x35d/0x480 arch/x86/entry/common.c:287
 [<ffffffff8278c053>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
2 locks held by khungtaskd/24:
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131401c>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff8131401c>] watchdog+0x11c/0xa20 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff813f99b9>] debug_show_all_locks+0x79/0x218 kernel/locking/lockdep.c:4336
2 locks held by getty/2215:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff8278a122>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff81cde522>] n_tty_read+0x202/0x16e0 drivers/tty/n_tty.c:2142
2 locks held by syz-executor7/2296:
 #0:  (&type->s_umount_key#38){+.+.+.}, at: [<ffffffff815071c9>] deactivate_super+0x89/0xd0 fs/super.c:340
 #1:  (&fc->killsb){++++.+}, at: [<ffffffff8185c600>] fuse_kill_sb_anon+0x50/0xb0 fs/fuse/inode.c:1206
1 lock held by syz-executor7/8874:
 #0:  (&fc->killsb){++++.+}, at: [<ffffffff81837b47>] fuse_notify_retrieve fs/fuse/dev.c:1725 [inline]
 #0:  (&fc->killsb){++++.+}, at: [<ffffffff81837b47>] fuse_notify fs/fuse/dev.c:1765 [inline]
 #0:  (&fc->killsb){++++.+}, at: [<ffffffff81837b47>] fuse_dev_do_write+0x1307/0x2090 fs/fuse/dev.c:1843

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.124+ #33
 ffff8801d9497d08 ffffffff81af4b39 0000000000000000 0000000000000001
 0000000000000001 0000000000000001 ffffffff81096740 ffff8801d9497d40
 ffffffff81aff897 0000000000000001 0000000000000000 0000000000000003
Call Trace:
 [<ffffffff81af4b39>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81af4b39>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81aff897>] nmi_cpu_backtrace.cold.0+0x48/0x87 lib/nmi_backtrace.c:99
 [<ffffffff81aff82a>] nmi_trigger_cpumask_backtrace+0x12a/0x14f lib/nmi_backtrace.c:60
 [<ffffffff81096844>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff813145ad>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff813145ad>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff813145ad>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff813145ad>] watchdog+0x6ad/0xa20 kernel/hung_task.c:239
 [<ffffffff811410dd>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff8278c21c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff8278ac66