unregister_netdevice: waiting for lo to become free. Usage count = 29
ref_tracker: lo@ffff88802e40c5b8 has 27/28 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline]
     netdev_hold include/linux/netdevice.h:4139 [inline]
     dst_init+0xd9/0x460 net/core/dst.c:52
     dst_alloc+0x12e/0x170 net/core/dst.c:93
     rt_dst_clone+0x58/0x680 net/ipv4/route.c:1685
     ip_mc_finish_output+0x10b/0x5f0 net/ipv4/ip_output.c:355
     NF_HOOK include/linux/netfilter.h:304 [inline]
     ip_mc_output+0x39c/0x580 net/ipv4/ip_output.c:415
     iptunnel_xmit+0x53e/0x9c0 net/ipv4/ip_tunnel_core.c:82
     udp_tunnel_xmit_skb+0x249/0x390 net/ipv4/udp_tunnel_core.c:172
     tipc_udp_xmit+0x7be/0xaa0 net/tipc/udp_media.c:198
     tipc_udp_send_msg+0x27e/0x3e0 net/tipc/udp_media.c:271
     tipc_bearer_xmit_skb+0x2ad/0x3f0 net/tipc/bearer.c:575
     tipc_disc_timeout+0x581/0x6d0 net/tipc/discover.c:338
     call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
     expire_timers kernel/time/timer.c:1751 [inline]
     __run_timers+0x52d/0x7d0 kernel/time/timer.c:2022
     run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
     handle_softirqs+0x280/0x820 kernel/softirq.c:578
     __do_softirq kernel/softirq.c:612 [inline]
     invoke_softirq kernel/softirq.c:452 [inline]
     __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661

ref_tracker: lo@ffff88802e40c5b8 has 1/28 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline]
     netdev_hold include/linux/netdevice.h:4139 [inline]
     dst_init+0xd9/0x460 net/core/dst.c:52
     dst_alloc+0x12e/0x170 net/core/dst.c:93
     rt_dst_clone+0x58/0x680 net/ipv4/route.c:1685
     ip_mc_finish_output+0x10b/0x5f0 net/ipv4/ip_output.c:355
     NF_HOOK include/linux/netfilter.h:304 [inline]
     ip_mc_output+0x39c/0x580 net/ipv4/ip_output.c:415
     iptunnel_xmit+0x53e/0x9c0 net/ipv4/ip_tunnel_core.c:82
     udp_tunnel_xmit_skb+0x249/0x390 net/ipv4/udp_tunnel_core.c:172
     tipc_udp_xmit+0x7be/0xaa0 net/tipc/udp_media.c:198
     tipc_udp_send_msg+0x27e/0x3e0 net/tipc/udp_media.c:271
     tipc_bearer_xmit_skb+0x2ad/0x3f0 net/tipc/bearer.c:575
     tipc_enable_bearer net/tipc/bearer.c:366 [inline]
     __tipc_nl_bearer_enable+0x100c/0x1360 net/tipc/bearer.c:1047
     tipc_nl_bearer_enable+0x22/0x30 net/tipc/bearer.c:1056
     genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:971
     genl_family_rcv_msg net/netlink/genetlink.c:1051 [inline]
     genl_rcv_msg+0x60b/0x790 net/netlink/genetlink.c:1066
     netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2537
     genl_rcv+0x28/0x40 net/netlink/genetlink.c:1075