unregister_netdevice: waiting for lo to become free. Usage count = 2
ref_tracker: netdev@ffff88805666e618 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4400 [inline]
     netdev_hold include/linux/netdevice.h:4429 [inline]
     dst_init+0xda/0x5b0 net/core/dst.c:52
     dst_alloc+0xbb/0x1a0 net/core/dst.c:94
     rt_dst_alloc+0x35/0x3a0 net/ipv4/route.c:1651
     __mkroute_output net/ipv4/route.c:2655 [inline]
     ip_route_output_key_hash_rcu+0x87a/0x28e0 net/ipv4/route.c:2875
     ip_route_output_key_hash+0x10f/0x2b0 net/ipv4/route.c:2705
     __ip_route_output_key include/net/route.h:169 [inline]
     ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2932
     ip_route_output_key include/net/route.h:179 [inline]
     sctp_v4_get_dst+0x3cf/0x1270 net/sctp/protocol.c:455
     sctp_transport_route+0x132/0x350 net/sctp/transport.c:448
     sctp_assoc_add_peer+0x76a/0x1540 net/sctp/associola.c:663
     sctp_connect_new_asoc+0x1f8/0x770 net/sctp/socket.c:1100
     sctp_sendmsg_new_asoc net/sctp/socket.c:1692 [inline]
     sctp_sendmsg+0x157c/0x1e20 net/sctp/socket.c:2003
     inet_sendmsg+0x11c/0x140 net/ipv4/af_inet.c:859
     sock_sendmsg_nosec net/socket.c:727 [inline]
     __sock_sendmsg net/socket.c:742 [inline]
     ____sys_sendmsg+0x973/0xc30 net/socket.c:2592
     ___sys_sendmsg+0x134/0x1d0 net/socket.c:2646
     __sys_sendmsg+0x16d/0x220 net/socket.c:2678
     do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
     do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94