fix possible null ptr deref

diff --git a/ext/standard/basic_functions.c b/ext/standard/basic_functions.c
index f37ae5614e9567e88aa7df7af320e61bc42acc7c..de4d71106b5ea086ff83ef6f01d035ef0a68d065 100644 (file)
--- a/ext/standard/basic_functions.c
+++ b/ext/standard/basic_functions.c
@@ -5011,7 +5011,11 @@ PHP_FUNCTION(register_shutdown_function)
 
        /* Prevent entering of anything but valid callback (syntax check only!) */
        if (!zend_is_callable(&shutdown_function_entry.arguments[0], 0, &callback_name TSRMLS_CC)) {
-               php_error_docref(NULL TSRMLS_CC, E_WARNING, "Invalid shutdown callback '%s' passed", callback_name->val);
+               if (callback_name) {
+                       php_error_docref(NULL TSRMLS_CC, E_WARNING, "Invalid shutdown callback '%s' passed", callback_name->val);
+               } else {
+                       php_error_docref(NULL TSRMLS_CC, E_WARNING, "Invalid shutdown callback passed");
+               }
                efree(shutdown_function_entry.arguments);
                RETVAL_FALSE;
        } else {