INFO: task syz-executor.4:2095 blocked for more than 140 seconds.
      Not tainted 4.9.194+ #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4  D25528  2095      1 0x00000004
 0000000000000083 ffff8801d7fe0000 ffff8801cf912c00 ffff8801db721000
 ffff8801cf81c740 ffff8801db721018 ffff8801a5027ad8 ffffffff8281af8e
 ffffea0006724240 ffffea0006724240 00ff8801a5027b10 ffff8801db7218f0
Call Trace:
 [<00000000578d7421>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
 [<00000000c3a22707>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579
 [<0000000094b85b3c>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<0000000094b85b3c>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621
 [<00000000f59f99d5>] __pipe_lock fs/pipe.c:87 [inline]
 [<00000000f59f99d5>] pipe_write+0xb6/0xe40 fs/pipe.c:384
 [<00000000039cadd2>] new_sync_write fs/read_write.c:498 [inline]
 [<00000000039cadd2>] __vfs_write+0x3c1/0x560 fs/read_write.c:511
 [<000000005d5fd3c1>] vfs_write+0x185/0x520 fs/read_write.c:559
 [<000000004528319d>] SYSC_write fs/read_write.c:607 [inline]
 [<000000004528319d>] SyS_write+0x121/0x270 fs/read_write.c:599
 [<000000007c82e8e7>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
 [<0000000044ea3e47>] 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: [<0000000026c10beb>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline]
 #0:  (rcu_read_lock){......}, at: [<0000000026c10beb>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263
 #1:  (tasklist_lock){.+.+..}, at: [<00000000f443efec>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/1900:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<00000000975ae8af>] __fdget_pos+0xa8/0xd0 fs/file.c:782
2 locks held by getty/2028:
 #0:  (&tty->ldisc_sem){++++++}, at: [<000000002f16debd>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+.+.}, at: [<0000000074971487>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.4/2095:
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<00000000f59f99d5>] __pipe_lock fs/pipe.c:87 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<00000000f59f99d5>] pipe_write+0xb6/0xe40 fs/pipe.c:384
1 lock held by syz-executor.4/23417:
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<00000000e14116cc>] pipe_lock_nested fs/pipe.c:66 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<00000000e14116cc>] pipe_lock+0x63/0x80 fs/pipe.c:74

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

NMI backtrace for cpu 1
CPU: 1 PID: 24 Comm: khungtaskd Not tainted 4.9.194+ #0
 ffff8801d98d7cc8 ffffffff81b67001 0000000000000001 0000000000000000
 0000000000000001 ffffffff81099d01 dffffc0000000000 ffff8801d98d7d00
 ffffffff81b7229c 0000000000000001 0000000000000000 0000000000000001
Call Trace:
 [<000000000a29a533>] __dump_stack lib/dump_stack.c:15 [inline]
 [<000000000a29a533>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<00000000fc9dae00>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99
 [<000000001aa0a644>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60
 [<00000000d469e251>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<000000007531c724>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<000000007531c724>] check_hung_task kernel/hung_task.c:126 [inline]
 [<000000007531c724>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline]
 [<000000007531c724>] watchdog+0x670/0xaf0 kernel/hung_task.c:263
 [<000000008ea59eb9>] kthread+0x278/0x310 kernel/kthread.c:211
 [<00000000ba46d3e1>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at pc 0xffffffff8282a0e1