Fix use-after-free in php_date.c

Author: iluuu1994

ext/date/php_date.c

@@ -2263,8 +2263,9 @@ PHPAPI zval *php_date_instantiate(zend_class_entry *pce, zval *object) /* {{{ */
 
 /* Helper function used to store the latest found warnings and errors while
  * parsing, from either strtotime or parse_from_format. */
-static void update_errors_warnings(timelib_error_container *last_errors) /* {{{ */
+static void update_errors_warnings(timelib_error_container **last_errors_ptr) /* {{{ */
 {
+	timelib_error_container *last_errors = *last_errors_ptr;
 	if (DATEG(last_errors)) {
 		timelib_error_container_dtor(DATEG(last_errors));
 		DATEG(last_errors) = NULL;
@@ -2273,6 +2274,7 @@ static void update_errors_warnings(timelib_error_container *last_errors) /* {{{
 		DATEG(last_errors) = last_errors;
 	} else {
 		timelib_error_container_dtor(last_errors);
+		*last_errors_ptr = NULL;
 	}
 } /* }}} */
 
@@ -2324,7 +2326,7 @@ PHPAPI bool php_date_initialize(php_date_obj *dateobj, const char *time_str, siz
 	}
 
 	/* update last errors and warnings */
-	update_errors_warnings(err);
+	update_errors_warnings(&err);
 
 	/* If called from a constructor throw an exception */
 	if ((flags & PHP_DATE_INIT_CTOR) && err && err->error_count) {
@@ -3002,7 +3004,7 @@ static bool php_date_modify(zval *object, char *modify, size_t modify_len) /* {{
 	tmp_time = timelib_strtotime(modify, modify_len, &err, DATE_TIMEZONEDB, php_date_parse_tzfile_wrapper);
 
 	/* update last errors and warnings */
-	update_errors_warnings(err);
+	update_errors_warnings(&err);
 	if (err && err->error_count) {
 		/* spit out the first library error message, at least */
 		php_error_docref(NULL, E_WARNING, "Failed to parse time string (%s) at position %d (%c): %s", modify,