pdo_odbc: Fix memory leak if WideCharToMultiByte() fails

ndossche · ndossche · commit 786090b35d2c · 2025-06-09T11:24:48.000+02:00
Closes phpGH-18788.
diff --git a/NEWS b/NEWS
@@ -34,6 +34,9 @@ PHP                                                                        NEWS
   . Add missing filter cleanups on phar failure. (nielsdos)
   . Fixed bug GH-18642 (Signed integer overflow in ext/phar fseek). (nielsdos)
 
+- PDO ODBC:
+  . Fix memory leak if WideCharToMultiByte() fails. (nielsdos)
+
 - PGSQL:
   . Fix warning not being emitted when failure to cancel a query with
     pg_cancel_query(). (Girgias)
diff --git a/ext/pdo_odbc/odbc_stmt.c b/ext/pdo_odbc/odbc_stmt.c
@@ -104,6 +104,7 @@ static int pdo_odbc_ucs22utf8(pdo_stmt_t *stmt, int is_unicode, zval *result)
 		zend_string *str = zend_string_alloc(ret, 0);
 		ret = WideCharToMultiByte(CP_UTF8, 0, (LPCWSTR) Z_STRVAL_P(result), Z_STRLEN_P(result)/sizeof(WCHAR), ZSTR_VAL(str), ZSTR_LEN(str), NULL, NULL);
 		if (ret == 0) {
+			zend_string_efree(str);
 			return PDO_ODBC_CONV_FAIL;
 		}
 

Original file line number	Diff line number	Diff line change
`@@ -104,6 +104,7 @@ static int pdo_odbc_ucs22utf8(pdo_stmt_t stmt, int is_unicode, zval result)`
`104`	`104`	`zend_string *str = zend_string_alloc(ret, 0);`
`105`	`105`	`ret = WideCharToMultiByte(CP_UTF8, 0, (LPCWSTR) Z_STRVAL_P(result), Z_STRLEN_P(result)/sizeof(WCHAR), ZSTR_VAL(str), ZSTR_LEN(str), NULL, NULL);`
`106`	`106`	`if (ret == 0) {`
	`107`	`+ zend_string_efree(str);`
`107`	`108`	`return PDO_ODBC_CONV_FAIL;`
`108`	`109`	`}`
`109`	`110`