unregister_netdevice: waiting for lo to become free. Usage count = 2
ref_tracker: lo@ffff8880609b4620 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4062 [inline]
     netdev_hold include/linux/netdevice.h:4091 [inline]
     dst_init+0xee/0x490 net/core/dst.c:52
     dst_alloc+0x14f/0x190 net/core/dst.c:93
     rt_dst_clone+0x52/0x650 net/ipv4/route.c:1640
     ip_mc_finish_output+0x102/0x570 net/ipv4/ip_output.c:356
     NF_HOOK include/linux/netfilter.h:314 [inline]
     ip_mc_output+0x3e1/0x5c0 net/ipv4/ip_output.c:416
     ip_local_out net/ipv4/ip_output.c:130 [inline]
     __ip_queue_xmit+0x118c/0x1b80 net/ipv4/ip_output.c:536
     sctp_packet_transmit+0x26af/0x2ca0 net/sctp/output.c:653
     sctp_packet_singleton+0x22c/0x320 net/sctp/outqueue.c:783
     sctp_outq_flush_ctrl net/sctp/outqueue.c:914 [inline]
     sctp_outq_flush+0x6d5/0x3e20 net/sctp/outqueue.c:1212
     sctp_side_effects net/sctp/sm_sideeffect.c:1198 [inline]
     sctp_do_sm+0x59cc/0x60c0 net/sctp/sm_sideeffect.c:1169
     sctp_primitive_ASSOCIATE+0x95/0xc0 net/sctp/primitive.c:73
     sctp_sendmsg_to_asoc+0xfa5/0x1800 net/sctp/socket.c:1841
     sctp_sendmsg+0x1bc3/0x3520 net/sctp/socket.c:2031
     sock_sendmsg_nosec net/socket.c:729 [inline]
     __sock_sendmsg+0x1a6/0x270 net/socket.c:744
     ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2607
     ___sys_sendmsg net/socket.c:2661 [inline]
     __sys_sendmsg+0x292/0x380 net/socket.c:2690