unregister_netdevice: waiting for lo to become free. Usage count = 2
leaked reference.
 __netdev_tracker_alloc include/linux/netdevice.h:4051 [inline]
 netdev_hold include/linux/netdevice.h:4080 [inline]
 dst_init+0xc8/0x3c0 net/core/dst.c:52
 dst_alloc+0x120/0x170 net/core/dst.c:92
 rt_dst_alloc net/ipv4/route.c:1662 [inline]
 ip_route_input_slow net/ipv4/route.c:2402 [inline]
 ip_route_input_rcu+0x1afc/0x29b4 net/ipv4/route.c:2516
 ip_route_input_noref+0x158/0x250 net/ipv4/route.c:2527
 ip_rcv_finish_core+0x484/0x18f0 net/ipv4/ip_input.c:365
 ip_rcv_finish+0x130/0x24c net/ipv4/ip_input.c:447
 NF_HOOK+0x2dc/0x36c include/linux/netfilter.h:302
 ip_rcv+0x7c/0x9c net/ipv4/ip_input.c:569
 __netif_receive_skb_one_core net/core/dev.c:5581 [inline]
 __netif_receive_skb+0xcc/0x2a8 net/core/dev.c:5695
 netif_receive_skb_internal net/core/dev.c:5781 [inline]
 netif_receive_skb+0x1e8/0x924 net/core/dev.c:5840
 tun_rx_batched+0x48c/0x5dc drivers/net/tun.c:-1
 tun_get_user+0x1fe8/0x3298 drivers/net/tun.c:1998
 tun_chr_write_iter+0xfc/0x200 drivers/net/tun.c:2044
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x3ec/0x7f0 fs/read_write.c:584
 ksys_write+0x12c/0x224 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646