syzbot

INFO: task kworker/u8:13:7810 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:13   state:D stack:20168 pid:7810  tgid:7810  ppid:2      task_flags:0x4208160 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307
 rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
 __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
 rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800
 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
 __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline]
 mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547
 rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142
 register_netdevice_notifier_dev_net+0x33/0x240 net/core/dev.c:2169
 nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1070 [inline]
 nsim_create+0xc3b/0x1060 drivers/net/netdevsim/netdev.c:1141
 __nsim_dev_port_add+0x6b6/0xb10 drivers/net/netdevsim/dev.c:1438
 nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1494
 nsim_dev_reload_create drivers/net/netdevsim/dev.c:1546 [inline]
 nsim_dev_reload_up+0x451/0x780 drivers/net/netdevsim/dev.c:1003
 devlink_reload+0x4f8/0x8d0 net/devlink/dev.c:474
 devlink_pernet_pre_exit+0x1d9/0x3d0 net/devlink/core.c:509
 ops_pre_exit_list net/core/net_namespace.c:161 [inline]
 ops_undo_list+0x187/0x990 net/core/net_namespace.c:234
 cleanup_net+0x4de/0x820 net/core/net_namespace.c:695