Fix bug #73768 - Memory corruption when loading hostile phar

Author: smalyshev

ext/phar/phar.c

@@ -981,15 +981,14 @@ static int phar_parse_pharfile(php_stream *fp, char *fname, int fname_len, char
 		/* if the alias is stored we enforce it (implicit overrides explicit) */
 		if (alias && alias_len && (alias_len != (int)tmp_len || strncmp(alias, buffer, tmp_len)))
 		{
-			buffer[tmp_len] = '\0';
 			php_stream_close(fp);
 
 			if (signature) {
 				efree(signature);
 			}
 
 			if (error) {
-				spprintf(error, 0, "cannot load phar \"%s\" with implicit alias \"%s\" under different alias \"%s\"", fname, buffer, alias);
+				spprintf(error, 0, "cannot load phar \"%s\" with implicit alias \"%.*s\" under different alias \"%s\"", fname, tmp_len, buffer, alias);
 			}
 
 			efree(savebuf);

ext/phar/tests/bug73768.phar

@@ -0,0 +1,16 @@
+--TEST--
+Phar: PHP bug #73768: Memory corruption when loading hostile phar
+--SKIPIF--
+<?php if (!extension_loaded("phar")) die("skip"); ?>
+--FILE--
+<?php
+chdir(__DIR__);
+try {
+$p = Phar::LoadPhar('bug73768.phar', 'alias.phar');
+echo "OK\n";
+} catch(PharException $e) {
+	echo $e->getMessage();
+}
+?>
+--EXPECTF--
+cannot load phar "%sbug73768.phar" with implicit alias "" under different alias "alias.phar"