unregister_netdevice: waiting for syz_tun to become free. Usage count = 2
ref_tracker: syz_tun@ffff88802c59c5b8 has 1/1 users at
     __netdev_tracker_alloc include/linux/netdevice.h:4110 [inline]
     netdev_tracker_alloc include/linux/netdevice.h:4122 [inline]
     netdev_get_by_index+0x79/0xa0 net/core/dev.c:911
     fib6_nh_init+0x203/0x1ff0 net/ipv6/route.c:3584
     ip6_route_info_create+0x94d/0x1240 net/ipv6/route.c:3854
     ip6_route_add+0x28/0x160 net/ipv6/route.c:3898
     addrconf_prefix_route net/ipv6/addrconf.c:2458 [inline]
     fixup_permanent_addr net/ipv6/addrconf.c:3588 [inline]
     addrconf_permanent_addr+0x6d4/0xa70 net/ipv6/addrconf.c:3612
     addrconf_notify+0x996/0x1010 net/ipv6/addrconf.c:3684
     notifier_call_chain+0x197/0x380 kernel/notifier.c:93
     call_netdevice_notifiers_extack net/core/dev.c:2077 [inline]
     call_netdevice_notifiers net/core/dev.c:2091 [inline]
     __dev_notify_flags+0x1aa/0x310 net/core/dev.c:8762
     dev_change_flags+0xe8/0x1a0 net/core/dev.c:8800
     do_setlink+0xc58/0x4130 net/core/rtnetlink.c:2908
     __rtnl_newlink net/core/rtnetlink.c:3706 [inline]
     rtnl_newlink+0x17da/0x20a0 net/core/rtnetlink.c:3753
     rtnetlink_rcv_msg+0x869/0xfa0 net/core/rtnetlink.c:6475
     netlink_rcv_skb+0x241/0x4d0 net/netlink/af_netlink.c:2545
     netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
     netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346
     netlink_sendmsg+0x8d0/0xbf0 net/netlink/af_netlink.c:1894
     sock_sendmsg_nosec net/socket.c:730 [inline]
     __sock_sendmsg net/socket.c:745 [inline]
     __sys_sendto+0x4a9/0x6b0 net/socket.c:2200