unregister_netdevice: waiting for syz_tun to become free. Usage count = 2
ref_tracker: netdev@ffff88802f4d4620 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4436 [inline]
     netdev_hold include/linux/netdevice.h:4465 [inline]
     netdev_hold include/linux/netdevice.h:4460 [inline]
     fib_check_nh_nongw net/ipv4/fib_semantics.c:1262 [inline]
     fib_check_nh+0x271/0x620 net/ipv4/fib_semantics.c:1282
     fib_create_info+0x218e/0x4640 net/ipv4/fib_semantics.c:1502
     fib_table_insert+0x169/0x1c70 net/ipv4/fib_trie.c:1212
     fib_magic+0x4d4/0x5c0 net/ipv4/fib_frontend.c:1134
     fib_add_ifaddr+0x4ba/0x560 net/ipv4/fib_frontend.c:1178
     fib_netdev_event+0x3d6/0x710 net/ipv4/fib_frontend.c:1516
     notifier_call_chain+0x99/0x420 kernel/notifier.c:85
     call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2249
     call_netdevice_notifiers_extack net/core/dev.c:2287 [inline]
     call_netdevice_notifiers net/core/dev.c:2301 [inline]
     __dev_notify_flags+0x12c/0x2e0 net/core/dev.c:9803
     netif_change_flags+0x108/0x160 net/core/dev.c:9832
     do_setlink.isra.0+0x1abb/0x3e50 net/core/rtnetlink.c:3158
     rtnl_changelink net/core/rtnetlink.c:3776 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3935 [inline]
     rtnl_newlink+0x11bd/0x2380 net/core/rtnetlink.c:4072
     rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6958
     netlink_rcv_skb+0x159/0x420 net/netlink/af_netlink.c:2550
     netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
     netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
     netlink_sendmsg+0x8b0/0xda0 net/netlink/af_netlink.c:1894