MacOS so_pcb type confusion in necp_get_socket_attributes(CVE-2017-13855)

When getsockopt edited; original report said "setsockopt" is called on any socket with level SOLSOCKET and optname SONECPATTRIBUTES, necpgetsocketattributes is invoked. necpgetsocketattributes unconditionally calls sotoinpcbso: errnot necpgetsocketattributesstruct socket so, struct sockopt sopt i...