unregister_netdevice: waiting for syz_tun to become free. Usage count = 2
ref_tracker: netdev@ffff8880299f0620 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4445 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4457 [inline]
     netdev_get_by_index+0x79/0xb0 net/core/dev.c:1027
     fib6_nh_init+0x202/0x1f90 net/ipv6/route.c:3600
     ip6_route_info_create_nh+0x16a/0xad0 net/ipv6/route.c:3899
     ip6_route_add+0x6e/0x1b0 net/ipv6/route.c:3951
     addrconf_prefix_route+0x3a2/0x480 net/ipv6/addrconf.c:2488
     addrconf_add_linklocal+0x266/0x460 net/ipv6/addrconf.c:3313
     addrconf_addr_gen+0x2f8/0x360 net/ipv6/addrconf.c:3447
     addrconf_notify+0xb1e/0x1050 net/ipv6/addrconf.c:3745
     notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85
     call_netdevice_notifiers_extack net/core/dev.c:2288 [inline]
     call_netdevice_notifiers net/core/dev.c:2302 [inline]
     __dev_notify_flags+0x1a9/0x310 net/core/dev.c:9833
     netif_change_flags+0xe8/0x1a0 net/core/dev.c:9862
     do_setlink+0xf82/0x4590 net/core/rtnetlink.c:3180
     rtnl_changelink net/core/rtnetlink.c:3798 [inline]
     __rtnl_newlink net/core/rtnetlink.c:3957 [inline]
     rtnl_newlink+0x15a9/0x1be0 net/core/rtnetlink.c:4094
     rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6980
     netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
     netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
     netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344