Fix memory leak on overflow in _php_stream_scandir()

On overflow, only the array is freed, but not the strings.

Closes phpGH-17789.

Author: ndossche

NEWS

@@ -41,6 +41,7 @@ PHP                                                                        NEWS
 
 - Streams:
   . Fixed bug GH-17650 (realloc with size 0 in user_filters.c). (nielsdos)
+  . Fix memory leak on overflow in _php_stream_scandir(). (nielsdos)
 
 - Windows:
   . Fixed phpize for Windows 11 (24H2). (bwoebi)

main/streams/streams.c

@@ -2469,25 +2469,19 @@ PHPAPI int _php_stream_scandir(const char *dirname, zend_string **namelist[], in
 				vector_size = 10;
 			} else {
 				if(vector_size*2 < vector_size) {
-					/* overflow */
-					php_stream_closedir(stream);
-					efree(vector);
-					return -1;
+					goto overflow;
 				}
 				vector_size *= 2;
 			}
-			vector = (zend_string **) safe_erealloc(vector, vector_size, sizeof(char *), 0);
+			vector = (zend_string **) safe_erealloc(vector, vector_size, sizeof(zend_string *), 0);
 		}
 
 		vector[nfiles] = zend_string_init(sdp.d_name, strlen(sdp.d_name), 0);
 
-		nfiles++;
-		if(vector_size < 10 || nfiles == 0) {
-			/* overflow */
-			php_stream_closedir(stream);
-			efree(vector);
-			return -1;
+		if(vector_size < 10 || nfiles + 1 == 0) {
+			goto overflow;
 		}
+		nfiles++;
 	}
 	php_stream_closedir(stream);
 
@@ -2497,5 +2491,13 @@ PHPAPI int _php_stream_scandir(const char *dirname, zend_string **namelist[], in
 		qsort(*namelist, nfiles, sizeof(zend_string *), (int(*)(const void *, const void *))compare);
 	}
 	return nfiles;
+
+overflow:
+	php_stream_closedir(stream);
+	for (unsigned int i = 0; i < nfiles; i++) {
+		zend_string_efree(vector[i]);
+	}
+	efree(vector);
+	return -1;
 }
 /* }}} */