unregister_netdevice: waiting for lo to become free. Usage count = 2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4051 [inline]
 netdev_tracker_alloc include/linux/netdevice.h:4063 [inline]
 fib6_nh_init+0x7b2/0x1e90 net/ipv6/route.c:3665
 nh_create_ipv6 net/ipv4/nexthop.c:2567 [inline]
 nexthop_create net/ipv4/nexthop.c:2618 [inline]
 nexthop_add net/ipv4/nexthop.c:2660 [inline]
 rtm_new_nexthop+0x281e/0x63c0 net/ipv4/nexthop.c:2939
 rtnetlink_rcv_msg+0x79b/0xed0 net/core/rtnetlink.c:6153
 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2493
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x74c/0x8c0 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1859
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x59b/0x970 net/socket.c:2519
 ___sys_sendmsg+0x21c/0x290 net/socket.c:2573
 __sys_sendmsg net/socket.c:2602 [inline]
 __do_sys_sendmsg net/socket.c:2611 [inline]
 __se_sys_sendmsg+0x19e/0x270 net/socket.c:2609
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2