r0 = socket$inet6_udp(0xa, 0x2, 0x0)
ioctl$sock_ipv6_tunnel_SIOCDELTUNNEL(r0, 0x89f2, &(0x7f0000000100)={'sit0\x00', &(0x7f0000000080)={'ip6tnl0\x00', 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @private2, @loopback}})