unregister_netdevice: waiting for lo to become free. Usage count = 2
ref_tracker: netdev@ffff88805ce4e618 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4375 [inline]
     netdev_hold include/linux/netdevice.h:4404 [inline]
     dst_init+0xda/0x580 net/core/dst.c:52
     dst_alloc+0xbb/0x1a0 net/core/dst.c:93
     rt_dst_alloc+0x35/0x3a0 net/ipv4/route.c:1646
     ip_route_input_slow+0x16cb/0x3fa0 net/ipv4/route.c:2424
     ip_route_input_rcu net/ipv4/route.c:2538 [inline]
     ip_route_input_noref+0x120/0x2e0 net/ipv4/route.c:2549
     ip_rcv_finish_core+0x46f/0x2290 net/ipv4/ip_input.c:368
     ip_rcv_finish net/ipv4/ip_input.c:451 [inline]
     NF_HOOK include/linux/netfilter.h:318 [inline]
     NF_HOOK include/linux/netfilter.h:312 [inline]
     ip_rcv+0x1c0/0x600 net/ipv4/ip_input.c:573
     __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6079
     __netif_receive_skb+0x1d/0x160 net/core/dev.c:6192
     netif_receive_skb_internal net/core/dev.c:6278 [inline]
     netif_receive_skb+0x137/0x7b0 net/core/dev.c:6337
     tun_rx_batched.isra.0+0x3ee/0x740 drivers/net/tun.c:1509
     tun_get_user+0x28b2/0x3cc0 drivers/net/tun.c:1953
     tun_chr_write_iter+0xdc/0x210 drivers/net/tun.c:1999
     new_sync_write fs/read_write.c:593 [inline]
     vfs_write+0x7d3/0x11d0 fs/read_write.c:686
     ksys_write+0x12a/0x250 fs/read_write.c:738
     do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
     do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94