memory corruption while parsing HTTP response

In the network interfacing PHP API file_get_contents(), a mechanism is implemented to parse the HTTP/S response from the remote host. A vulnerability is found when the vulnerable PHP build processes certain malformed HTTP/S response packets, resulting an array negative indexing.

php_stream_url_wrap_http_ex /home/weilei/php-7.2.2/ext/standard/http_fopen_wrapper.c:723

			if (tmp_line[tmp_line_len - 1] == '\n') {
				--tmp_line_len;
				if (tmp_line[tmp_line_len - 1] == '\r') {
					--tmp_line_len;
				}