INFO: task syz-executor.0:3241 blocked for more than 140 seconds.
      Not tainted 4.9.190+ #2
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.0  D27240  3241   2108 0x00000004
 0000000000000083 ffff8801c5d70000 ffff8801d1129b80 ffff8801db721000
 ffff8801d1885f00 ffff8801db721018 ffff8801ae4cfc78 ffffffff8281a10e
 0000000000000000 0000000000000000 00ffffff83c7c1d0 ffff8801db7218f0
Call Trace:
 [<0000000028259ce2>] schedule+0x92/0x1c0 kernel/sched/core.c:3546
 [<0000000010744790>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3579
 [<000000003ef5c2ee>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<000000003ef5c2ee>] mutex_lock_nested+0x38d/0x920 kernel/locking/mutex.c:621
 [<00000000ab86aecf>] __pipe_lock fs/pipe.c:87 [inline]
 [<00000000ab86aecf>] pipe_release+0x4e/0x250 fs/pipe.c:582
 [<00000000f4b311ed>] __fput+0x274/0x720 fs/file_table.c:208
 [<00000000dc0460d1>] ____fput+0x16/0x20 fs/file_table.c:244
 [<00000000e0700a71>] task_work_run+0x108/0x180 kernel/task_work.c:116
 [<000000003db28b4c>] tracehook_notify_resume include/linux/tracehook.h:191 [inline]
 [<000000003db28b4c>] exit_to_usermode_loop+0x13b/0x160 arch/x86/entry/common.c:163
 [<0000000058992ba8>] prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 [<0000000058992ba8>] syscall_return_slowpath arch/x86/entry/common.c:266 [inline]
 [<0000000058992ba8>] do_syscall_64+0x3ab/0x5c0 arch/x86/entry/common.c:293
 [<0000000028008a47>] 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: [<000000008c505f2f>] check_hung_uninterruptible_tasks kernel/hung_task.c:169 [inline]
 #0:  (rcu_read_lock){......}, at: [<000000008c505f2f>] watchdog+0x14b/0xaf0 kernel/hung_task.c:263
 #1:  (tasklist_lock){.+.+..}, at: [<00000000b18a4b6f>] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4336
2 locks held by getty/2033:
 #0:  (&tty->ldisc_sem){++++++}, at: [<00000000fcd0e827>] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<00000000caf66cd9>] n_tty_read+0x1fe/0x1820 drivers/tty/n_tty.c:2156
1 lock held by syz-executor.0/3241:
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<00000000ab86aecf>] __pipe_lock fs/pipe.c:87 [inline]
 #0:  (&pipe->mutex/1){+.+.+.}, at: [<00000000ab86aecf>] pipe_release+0x4e/0x250 fs/pipe.c:582

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

NMI backtrace for cpu 0
CPU: 0 PID: 24 Comm: khungtaskd Not tainted 4.9.190+ #2
 ffff8801d98d7cc8 ffffffff81b66c51 0000000000000000 0000000000000000
 0000000000000000 ffffffff81099a01 dffffc0000000000 ffff8801d98d7d00
 ffffffff81b71eec 0000000000000000 0000000000000000 0000000000000000
Call Trace:
 [<00000000417ca2cc>] __dump_stack lib/dump_stack.c:15 [inline]
 [<00000000417ca2cc>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<000000004d992e9c>] nmi_cpu_backtrace.cold+0x47/0x87 lib/nmi_backtrace.c:99
 [<0000000036672b3a>] nmi_trigger_cpumask_backtrace+0x124/0x155 lib/nmi_backtrace.c:60
 [<000000007381f56e>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<00000000676f002f>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<00000000676f002f>] check_hung_task kernel/hung_task.c:126 [inline]
 [<00000000676f002f>] check_hung_uninterruptible_tasks kernel/hung_task.c:183 [inline]
 [<00000000676f002f>] watchdog+0x670/0xaf0 kernel/hung_task.c:263
 [<00000000076e094a>] kthread+0x278/0x310 kernel/kthread.c:211
 [<00000000754a5852>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:375
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3260 Comm: syz-executor.0 Not tainted 4.9.190+ #2
task: 000000004214e1c9 task.stack: 00000000c6912081
RIP: 0010:[<ffffffff811748e1>] 
c [<00000000be6bb4dd>] constant_test_bit arch/x86/include/asm/bitops.h:311 [inline]
RIP: 0010:[<ffffffff811748e1>] 
c [<00000000be6bb4dd>] test_ti_thread_flag include/linux/thread_info.h:58 [inline]
RIP: 0010:[<ffffffff811748e1>] 
c [<00000000be6bb4dd>] test_tsk_thread_flag include/linux/sched.h:3396 [inline]
RIP: 0010:[<ffffffff811748e1>] 
c [<00000000be6bb4dd>] test_tsk_need_resched include/linux/sched.h:3411 [inline]
RIP: 0010:[<ffffffff811748e1>] 
c [<00000000be6bb4dd>] check_preempt_curr+0x131/0x3b0 kernel/sched/core.c:976
RSP: 0018:ffff8801db707c50  EFLAGS: 00000046
RAX: dffffc0000000000 RBX: ffff8801db721000 RCX: ffff8801db721000
RDX: 0000000000000000 RSI: ffffffff81bcd2ac RDI: ffff8801a9d5981c
RBP: ffff8801db707c98 R08: ffff8801db7218f0 R09: 0000000000000003
R10: ffff8801cf668270 R11: 00000042adfd121a R12: ffffffff82a4ca80
R13: ffffffff82a4ca80 R14: 0000000000000000 R15: ffff8801a9d597c0
FS:  00007f4c2ff4e700(0000) GS:ffff8801db700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000201c1000 CR3: 00000001c73f3000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffff8801cf668288
c ffff8801db721170
c ffff8801db7218f0
c ffff8801db721000
c
 ffff8801db721000
c ffff8801cf668000
c ffff8801db707d80
c 0000000000000000
c
 ffff8801cf6687f8
c ffff8801db707cd8
c ffffffff81174b7f
c ffffffff8117409a
c
Call Trace:
 <IRQ> 
d [<000000002376f83a>] ttwu_do_wakeup.isra.0+0x1f/0x580 kernel/sched/core.c:1707
 [<0000000085645ac8>] ttwu_do_activate+0x154/0x200 kernel/sched/core.c:1753
 [<00000000f676b07c>] ttwu_queue kernel/sched/core.c:1908 [inline]
 [<00000000f676b07c>] try_to_wake_up+0x5a3/0x1030 kernel/sched/core.c:2122
 [<0000000099c2eec4>] wake_up_process+0x10/0x20 kernel/sched/core.c:2197
 [<000000004a793869>] hrtimer_wakeup+0x48/0x60 kernel/time/hrtimer.c:1476
 [<00000000bb1d690f>] __run_hrtimer kernel/time/hrtimer.c:1255 [inline]
 [<00000000bb1d690f>] __hrtimer_run_queues+0x313/0xe00 kernel/time/hrtimer.c:1319
 [<00000000fbb5c62a>] hrtimer_interrupt+0x1b6/0x450 kernel/time/hrtimer.c:1353
 [<00000000028425ba>] local_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:937
 [<00000000ff1e574e>] smp_apic_timer_interrupt+0x79/0xb0 arch/x86/kernel/apic/apic.c:961
 [<000000003a8e397b>] apic_timer_interrupt+0xa5/0xb0 arch/x86/entry/entry_64.S:653
 <EOI> 
d [<00000000cb094bbe>] ? arch_local_irq_restore arch/x86/include/asm/paravirt.h:768 [inline]
 <EOI> 
d [<00000000cb094bbe>] ? lock_acquire+0x176/0x3d0 kernel/locking/lockdep.c:3759
 [<00000000448bb6ae>] down_read+0x44/0xb0 kernel/locking/rwsem.c:22
 [<000000007f5cbf92>] ext4_page_mkwrite+0x1a5/0x1040 fs/ext4/inode.c:5768
 [<00000000ecd89c9f>] do_page_mkwrite+0x1d1/0x400 mm/memory.c:2061
 [<00000000efe1e017>] wp_page_shared mm/memory.c:2326 [inline]
 [<00000000efe1e017>] do_wp_page+0xab8/0x20a0 mm/memory.c:2430
 [<00000000f53a0c0e>] handle_pte_fault mm/memory.c:3562 [inline]
 [<00000000f53a0c0e>] __handle_mm_fault mm/memory.c:3634 [inline]
 [<00000000f53a0c0e>] handle_mm_fault+0xeff/0x2420 mm/memory.c:3671
 [<000000000dd18bd1>] __do_page_fault+0x3f0/0xa60 arch/x86/mm/fault.c:1401
 [<000000002208325f>] do_page_fault+0x28/0x30 arch/x86/mm/fault.c:1464
 [<000000007765be44>] page_fault+0x25/0x30 arch/x86/entry/entry_64.S:956
 [<000000007b24413d>] pipe_to_user+0xb0/0x160 fs/splice.c:1256
 [<00000000efac710f>] splice_from_pipe_feed fs/splice.c:521 [inline]
 [<00000000efac710f>] __splice_from_pipe+0x351/0x790 fs/splice.c:645
 [<00000000c1819c92>] vmsplice_to_user+0x1bd/0x1e0 fs/splice.c:1291
 [<000000008ea6c812>] SYSC_vmsplice fs/splice.c:1370 [inline]
 [<000000008ea6c812>] SyS_vmsplice+0x114/0x140 fs/splice.c:1353
 [<000000005d5048d5>] do_syscall_64+0x1ad/0x5c0 arch/x86/entry/common.c:288
 [<0000000028008a47>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
Code: 
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c