unregister_netdevice: waiting for vcan0 to become free. Usage count = 2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4051 [inline]
 netdev_tracker_alloc+0x68/0xb4 include/linux/netdevice.h:4063
 fib_create_info+0x1990/0x1e58 net/ipv4/fib_semantics.c:1552
 fib_table_insert+0xac/0x1368 net/ipv4/fib_trie.c:1217
 fib_magic+0x250/0x31c net/ipv4/fib_frontend.c:1118
 fib_add_ifaddr+0x118/0x4f8 net/ipv4/fib_frontend.c:1140
 fib_inetaddr_event+0x12c/0x200 net/ipv4/fib_frontend.c:1454
 notifier_call_chain kernel/notifier.c:87 [inline]
 blocking_notifier_call_chain+0xf0/0x198 kernel/notifier.c:382
 __inet_insert_ifa+0x858/0x9fc net/ipv4/devinet.c:569
 inet_rtm_newaddr+0xd74/0x1590 net/ipv4/devinet.c:971
 rtnetlink_rcv_msg+0x734/0xce4 net/core/rtnetlink.c:6153
 netlink_rcv_skb+0x208/0x3c4 net/netlink/af_netlink.c:2493
 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6171
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0x600/0x818 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x6e8/0x9b0 net/netlink/af_netlink.c:1859
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 __sys_sendto+0x304/0x3fc net/socket.c:2153
 __do_sys_sendto net/socket.c:2165 [inline]
 __se_sys_sendto net/socket.c:2161 [inline]
 __arm64_sys_sendto+0xd8/0xf8 net/socket.c:2161