unregister_netdevice: waiting for batadv_slave_0 to become free. Usage count = 2
ref_tracker: netdev@ffff888024836610 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4349 [inline]
     netdev_hold include/linux/netdevice.h:4378 [inline]
     batadv_hardif_add_interface net/batman-adv/hard-interface.c:877 [inline]
     batadv_hard_if_event+0xf0f/0x1730 net/batman-adv/hard-interface.c:957
     notifier_call_chain+0x1b3/0x3e0 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:11244
     veth_newlink+0x5cc/0xa50 drivers/net/veth.c:1884
     rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3825
     __rtnl_newlink net/core/rtnetlink.c:3942 [inline]
     rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057
     rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6946
     netlink_rcv_skb+0x205/0x470 net/netlink/af_netlink.c:2552
     netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
     netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346
     netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
     sock_sendmsg_nosec net/socket.c:714 [inline]
     __sock_sendmsg+0x21c/0x270 net/socket.c:729
     __sys_sendto+0x3bd/0x520 net/socket.c:2228
     __do_compat_sys_socketcall net/compat.c:-1 [inline]
     __se_compat_sys_socketcall net/compat.c:423 [inline]
     __ia32_compat_sys_socketcall+0x71c/0x9c0 net/compat.c:423
     do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
     __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306
     do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
     entry_SYSENTER_compat_after_hwframe+0x84/0x8e