INFO: task kworker/u8:5:72 blocked for more than 145 seconds.
      Tainted: G     U       L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:5    state:D stack:23336 pid:72    tgid:72    ppid:2      task_flags:0x4208160 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0xfee/0x60e0 kernel/sched/core.c:6907
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7004
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 rtnl_net_dev_lock+0x146/0x360 net/core/dev.c:2155
 unregister_netdevice_notifier_dev_net+0x2c/0x2d0 net/core/dev.c:2200
 nsim_destroy+0xf6/0x830 drivers/net/netdevsim/netdev.c:1173
 __nsim_dev_port_del+0x189/0x240 drivers/net/netdevsim/dev.c:1529
 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1541 [inline]
 nsim_dev_reload_destroy+0x10a/0x4a0 drivers/net/netdevsim/dev.c:1765