unregister_netdevice: waiting for lo to become free. Usage count = 3
ref_tracker: netdev@ffff888036268620 has 2/2 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4454 [inline]
     netdev_hold include/linux/netdevice.h:4483 [inline]
     dst_init+0xd9/0x480 net/core/dst.c:52
     dst_alloc+0x12a/0x170 net/core/dst.c:94
     rt_dst_alloc net/ipv4/route.c:1651 [inline]
     ip_route_input_slow net/ipv4/route.c:2429 [inline]
     ip_route_input_rcu+0x23e5/0x3130 net/ipv4/route.c:2543
     ip_route_input_noref+0x17c/0x270 net/ipv4/route.c:2554
     ip_rcv_finish_core+0x5af/0x1c00 net/ipv4/ip_input.c:407
     ip_rcv_finish+0x14c/0x2a0 net/ipv4/ip_input.c:490
     NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318
     __netif_receive_skb_one_core net/core/dev.c:6209 [inline]
     __netif_receive_skb net/core/dev.c:6322 [inline]
     netif_receive_skb_internal net/core/dev.c:6408 [inline]
     netif_receive_skb+0x45b/0xbf0 net/core/dev.c:6467
     tun_rx_batched+0x1de/0x790 drivers/net/tun.c:1487
     tun_get_user+0x2aeb/0x3ed0 drivers/net/tun.c:1955
     tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:2001
     new_sync_write fs/read_write.c:595 [inline]
     vfs_write+0x61d/0xb90 fs/read_write.c:688
     ksys_write+0x150/0x270 fs/read_write.c:740
     do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
     do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
     entry_SYSCALL_64_after_hwframe+0x77/0x7f