unregister_netdevice: waiting for vcan0 to become free. Usage count = 2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4049 [inline]
 netdev_tracker_alloc+0x68/0xb4 include/linux/netdevice.h:4061
 fib_create_info+0x127c/0x1e98 net/ipv4/fib_semantics.c:1552
 fib_table_insert+0xb0/0x13fc net/ipv4/fib_trie.c:1217
 fib_magic+0x26c/0x344 net/ipv4/fib_frontend.c:1118
 fib_add_ifaddr+0x114/0x500 net/ipv4/fib_frontend.c:1140
 fib_inetaddr_event+0x12c/0x1f8 net/ipv4/fib_frontend.c:1454
 notifier_call_chain kernel/notifier.c:87 [inline]
 blocking_notifier_call_chain+0xf4/0x19c kernel/notifier.c:382
 __inet_insert_ifa+0x88c/0xa34 net/ipv4/devinet.c:568
 inet_rtm_newaddr+0x8b4/0x15bc net/ipv4/devinet.c:970
 rtnetlink_rcv_msg+0x694/0xcc4 net/core/rtnetlink.c:6158
 netlink_rcv_skb+0x220/0x3ec net/netlink/af_netlink.c:2516
 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6176
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x5fc/0x80c net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x6f0/0x9d8 net/netlink/af_netlink.c:1877
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x324/0x440 net/socket.c:2153
 __do_sys_sendto net/socket.c:2165 [inline]
 __se_sys_sendto net/socket.c:2161 [inline]
 __arm64_sys_sendto+0xe4/0x104 net/socket.c:2161