r0 = socket$inet6_udp(0xa, 0x2, 0x0)
ioctl$sock_ipv6_tunnel_SIOCADDTUNNEL(r0, 0x89f1, &(0x7f0000000200)={'sit0\x00', &(0x7f0000000180)={'syztnl0\x00', 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @private1, @mcast1}})