unregister_netdevice: waiting for syz_tun to become free. Usage count = 2
ref_tracker: netdev@ffff888058d88700 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4528 [inline]
     netdev_hold include/linux/netdevice.h:4557 [inline]
     fib_check_nh_nongw net/ipv4/fib_semantics.c:1290 [inline]
     fib_check_nh+0xcf1/0x1ac0 net/ipv4/fib_semantics.c:1310
     fib_create_info+0x200e/0x3170 net/ipv4/fib_semantics.c:1530
     fib_table_insert+0xcb/0x1b10 net/ipv4/fib_trie.c:1212
     fib_magic+0x43b/0x530 net/ipv4/fib_frontend.c:1147
     fib_add_ifaddr+0x3e6/0x5d0 net/ipv4/fib_frontend.c:1191
     fib_netdev_event+0x382/0x490 net/ipv4/fib_frontend.c:1529
     notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
     call_netdevice_notifiers_extack net/core/dev.c:2313 [inline]
     call_netdevice_notifiers net/core/dev.c:2327 [inline]
     __dev_notify_flags+0x31e/0x510 net/core/dev.c:9853
     netif_change_flags+0xde/0x1b0 net/core/dev.c:9882
     do_setlink+0xdd6/0x4670 net/core/rtnetlink.c:3266
     rtnl_changelink net/core/rtnetlink.c:3905 [inline]
     __rtnl_newlink net/core/rtnetlink.c:4076 [inline]
     rtnl_newlink+0x15a3/0x1c30 net/core/rtnetlink.c:4215
     rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7132
     netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
     netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
     netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1345
     netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
     sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800