GH-93990: fix refcounting bug in `add_subclass` in `typeobject.c` (GH-93989) (GH...

(cherry picked from commit 726448ebe15cd78e180c29c9858cb6c10a581524)

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 50f2742f676f68f0b7083d42a0ee5fc4eee3358d..65a9475ab7d7fe4737c58c7c3c3a05cef0f76f4c 100644 (file)
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -6400,8 +6400,11 @@ add_subclass(PyTypeObject *base, PyTypeObject *type)
     PyObject *dict = base->tp_subclasses;
     if (dict == NULL) {
         base->tp_subclasses = dict = PyDict_New();
-        if (dict == NULL)
+        if (dict == NULL) {
+            Py_DECREF(key);
+            Py_DECREF(ref);
             return -1;
+        }
     }
     assert(PyDict_CheckExact(dict));