unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
unregister_netdevice: waiting for lo to become free. Usage count = 3
INFO: task syz-executor4:19579 blocked for more than 120 seconds.
      Not tainted 4.16.0-rc6+ #288
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D25496 19579   4413 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2862 [inline]
 __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440
 schedule+0xf5/0x430 kernel/sched/core.c:3499
 __rwsem_down_write_failed_common+0x7c0/0x1540 kernel/locking/rwsem-xadd.c:566
 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595
 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117
 __down_write arch/x86/include/asm/rwsem.h:142 [inline]
 down_write+0xa2/0x120 kernel/locking/rwsem.c:72
 register_netdevice_notifier+0xb4/0x890 net/core/dev.c:1629
 raw_init+0x2a3/0x330 net/can/raw.c:343
 can_create+0x264/0x470 net/can/af_can.c:183
 __sock_create+0x4d4/0x850 net/socket.c:1285
 sock_create net/socket.c:1325 [inline]
 SYSC_socket net/socket.c:1355 [inline]
 SyS_socket+0xeb/0x1d0 net/socket.c:1335
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x454e79
RSP: 002b:00007f8dc5cefc68 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007f8dc5cf06d4 RCX: 0000000000454e79
RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000060f R14: 00000000006fb208 R15: 0000000000000000
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 PID: 877 Comm: khungtaskd Not tainted 4.16.0-rc6+ #288
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x24d lib/dump_stack.c:53
 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x123/0x180 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:138 [inline]
 check_hung_task kernel/hung_task.c:132 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
 watchdog+0x90c/0xd60 kernel/hung_task.c:249
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54
Kernel panic - not syncing: hung_task: blocked tasks
CPU: 1 PID: 877 Comm: khungtaskd Not tainted 4.16.0-rc6+ #288
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x24d lib/dump_stack.c:53
 panic+0x1e4/0x41c kernel/panic.c:183
 check_hung_task kernel/hung_task.c:133 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline]
 watchdog+0x91d/0xd60 kernel/hung_task.c:249
 kthread+0x33c/0x400 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406
Dumping ftrace buffer:
   (ftrace buffer empty)
Kernel Offset: disabled
Rebooting in 86400 seconds..