INFO: task syz-executor0:1323 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc7+ #279
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D24504  1323   6627 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: Bad RIP value.
RSP: 002b:00007fab41f59c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457519
RDX: 0000000000000008 RSI: 00000000200000c0 RDI: 0000000000000005
RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fab41f5a6d4
R13: 00000000004c51a3 R14: 00000000004d8868 R15: 00000000ffffffff
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 PID: 982 Comm: khungtaskd Not tainted 4.19.0-rc7+ #279
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 1 to CPUs 0:
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.247 msecs
NMI backtrace for cpu 0
CPU: 0 PID: 3194 Comm: udevd Not tainted 4.19.0-rc7+ #279
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:strlen+0x45/0xa0 lib/string.c:482
Code: 48 83 ec 08 0f b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 4d 41 80 3c 24 00 74 3b 48 bb 00 00 00 00 00 fc ff df 4c 89 e0 <48> 83 c0 01 48 89 c2 48 89 c1 48 c1 ea 03 83 e1 07 0f b6 14 1a 38
RSP: 0018:ffff8801c831f318 EFLAGS: 00000002
RAX: ffffffff8815c5e4 RBX: dffffc0000000000 RCX: 0000000000000004
RDX: 0000000000000000 RSI: ffff8801c864e158 RDI: ffffffff8815c5e0
RBP: ffff8801c831f330 R08: 0000000000000000 R09: ffffed00390c9c28
R10: ffffed00390c9c28 R11: ffff8801c864e143 R12: ffffffff8815c5e0
R13: ffffffff89382d60 R14: ffff8801bfd73528 R15: ffff8801c831f4e0
FS:  00007fd74201f7a0(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000001c8182000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 trace_event_get_offsets_lock_acquire include/trace/events/lock.h:13 [inline]
 perf_trace_lock+0xe2/0x7a0 include/trace/events/lock.h:39
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0x5dc/0x970 kernel/locking/lockdep.c:3918
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:166 [inline]
 _raw_spin_unlock_irq+0x1a/0x80 kernel/locking/spinlock.c:192
 spin_unlock_irq include/linux/spinlock.h:379 [inline]
 ep_scan_ready_list+0xbc7/0x1050 fs/eventpoll.c:752
 ep_send_events fs/eventpoll.c:1713 [inline]
 ep_poll+0x572/0x13d0 fs/eventpoll.c:1840
 do_epoll_wait+0x1b0/0x200 fs/eventpoll.c:2198
 __do_sys_epoll_wait fs/eventpoll.c:2208 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2205 [inline]
 __x64_sys_epoll_wait+0x97/0xf0 fs/eventpoll.c:2205
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fd741733943
Code: 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 83 3d b5 dc 2a 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 3b c4 00 00 48 89 04 24
RSP: 002b:00007ffcd6706c48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007fd741733943
RDX: 0000000000000008 RSI: 00007ffcd6706d40 RDI: 000000000000000a
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000001034340 R15: 000000000102d250