unregister_netdevice: waiting for ip6gretap1 to become free. Usage count = 2
ref_tracker: netdev@ffff88805b4be610 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4375 [inline]
     netdev_hold include/linux/netdevice.h:4404 [inline]
     batadv_hardif_add_interface net/batman-adv/hard-interface.c:878 [inline]
     batadv_hard_if_event+0xf0f/0x1730 net/batman-adv/hard-interface.c:958
     notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
     call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
     call_netdevice_notifiers net/core/dev.c:2281 [inline]
     register_netdevice+0x1608/0x1ae0 net/core/dev.c:11332
     ip6gre_newlink_common+0x3dd/0x590 net/ipv6/ip6_gre.c:1956
     ip6gre_newlink+0x228/0x360 net/ipv6/ip6_gre.c:1989
     rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3833
     __rtnl_newlink net/core/rtnetlink.c:3950 [inline]
     rtnl_newlink+0x16e4/0x1c80 net/core/rtnetlink.c:4065
     rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6954
     netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
     netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
     netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
     netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
     sock_sendmsg_nosec net/socket.c:727 [inline]
     __sock_sendmsg+0x21c/0x270 net/socket.c:742
     ____sys_sendmsg+0x505/0x830 net/socket.c:2630
     ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
     __sys_sendmsg net/socket.c:2716 [inline]
     __do_sys_sendmsg net/socket.c:2721 [inline]
     __se_sys_sendmsg net/socket.c:2719 [inline]
     __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
     do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
     do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94