r0 = socket$inet6_udp(0xa, 0x2, 0x0)
ioctl$sock_ipv6_tunnel_SIOCCHGTUNNEL(r0, 0x89f3, &(0x7f0000000000)={'sit0\x00', &(0x7f0000000100)={'syztnl2\x00', 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @empty, @initdev={0xfe, 0x88, '\x00', 0x0, 0x0}}})