INFO: task syz-executor0:13812 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc7+ #54
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D25400 13812   5856 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3575
 __mutex_lock_common kernel/locking/mutex.c:1002 [inline]
 __mutex_lock+0xbe7/0x1700 kernel/locking/mutex.c:1072
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
 __fdget_pos+0x1bb/0x200 fs/file.c:766
 fdget_pos include/linux/file.h:70 [inline]
 ksys_write+0x7f/0x260 fs/read_write.c:593
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457519
Code: 87 0a 8b 0d dd 60 09 01 83 f9 01 0f 85 1c 01 00 00 b9 01 00 00 00 88 0d 19 66 09 01 84 c9 0f 84 fd 00 00 00 b9 01 00 00 00 88 <0d> 02 66 09 01 48 8b 05 9b 71 07 01 48 89 04 24 e8 42 2c fc ff 8b
RSP: 002b:00007f9a77983c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457519
RDX: 0000000000000018 RSI: 0000000020000400 RDI: 0000000000000006
RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9a779846d4
R13: 00000000004c4fe7 R14: 00000000004d8640 R15: 00000000ffffffff
INFO: lockdep is turned off.
NMI backtrace for cpu 0
CPU: 0 PID: 983 Comm: khungtaskd Not tainted 4.19.0-rc7+ #54
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline]
 watchdog+0xb3e/0x1050 kernel/hung_task.c:265
 kthread+0x35a/0x420 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57