[   87.514460] unregister_netdevice: waiting for ktst-veth to become free. Usage count = 18
[   87.514567] unregister_netdevice: waiting for lo to become free. Usage count = 6
[   87.514655] unregister_netdevice: waiting for ktst-veth to become free. Usage count = 16
[   87.514731] unregister_netdevice: waiting for lo to become free. Usage count = 4