unregister_netdevice: waiting for lo to become free. Usage count = 67
ref_tracker: lo@ffff88802b9d2610 has 7/66 users at
     dst_init+0xd9/0x450
     dst_alloc+0x12a/0x170
     rt_dst_clone+0x52/0x680
     ip_mc_finish_output+0x10a/0x5f0
     ip_mc_output+0x3a3/0x590
     iptunnel_xmit+0x571/0xa00
     udp_tunnel_xmit_skb+0x266/0x3c0
     tipc_udp_xmit+0x7c7/0xab0
     tipc_udp_send_msg+0x27f/0x3f0
     tipc_bearer_xmit_skb+0x2b3/0x400
     tipc_disc_timeout+0x580/0x6d0
     call_timer_fn+0x17e/0x5f0
     __run_timer_base+0x61a/0x860
     run_timer_softirq+0xb7/0x180
     handle_softirqs+0x286/0x870
     __irq_exit_rcu+0xca/0x1f0

ref_tracker: lo@ffff88802b9d2610 has 59/66 users at
     dst_init+0xd9/0x450
     dst_alloc+0x12a/0x170
     rt_dst_clone+0x52/0x680
     ip_mc_finish_output+0x10a/0x5f0
     ip_mc_output+0x3a3/0x590
     iptunnel_xmit+0x571/0xa00
     udp_tunnel_xmit_skb+0x266/0x3c0
     tipc_udp_xmit+0x7c7/0xab0
     tipc_udp_send_msg+0x27f/0x3f0
     tipc_bearer_xmit_skb+0x2b3/0x400
     tipc_disc_timeout+0x580/0x6d0
     call_timer_fn+0x17e/0x5f0
     __run_timer_base+0x61a/0x860
     run_timer_softirq+0xb7/0x180
     handle_softirqs+0x286/0x870
     do_softirq+0xec/0x180

