unregister_netdevice: waiting for batadv_slave_0 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+0x620/0x19cc net/ipv6/route.c:3665
 nh_create_ipv6 net/ipv4/nexthop.c:2574 [inline]
 nexthop_create net/ipv4/nexthop.c:2625 [inline]
 nexthop_add net/ipv4/nexthop.c:2667 [inline]
 rtm_new_nexthop+0x2040/0x5694 net/ipv4/nexthop.c:2946
 rtnetlink_rcv_msg+0x734/0xce4 net/core/rtnetlink.c:6150
 netlink_rcv_skb+0x208/0x3c4 net/netlink/af_netlink.c:2511
 rtnetlink_rcv+0x28/0x38 net/core/rtnetlink.c:6168
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x60c/0x824 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x6e8/0x9b0 net/netlink/af_netlink.c:1872
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x5b8/0x918 net/socket.c:2519
 ___sys_sendmsg net/socket.c:2573 [inline]
 __sys_sendmsg+0x25c/0x320 net/socket.c:2602
 __do_sys_sendmsg net/socket.c:2611 [inline]
 __se_sys_sendmsg net/socket.c:2609 [inline]
 __arm64_sys_sendmsg+0x80/0x94 net/socket.c:2609
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2bc arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x13c arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x138 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585