r0 = socket$inet6_udp(0xa, 0x2, 0x0)
ioctl$sock_ipv6_tunnel_SIOCDELTUNNEL(r0, 0x89f2, &(0x7f00000019c0)={'sit0\x00', &(0x7f0000001940)={'syztnl2\x00', 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @private1, @ipv4={'\x00', '\xff\xff', @local}}})