From 15c8838273e1be94dc3f32db21a35f5302ed1a1d Mon Sep 17 00:00:00 2001
From: "Miss Islington (bot)"
 <31488909+miss-islington@users.noreply.github.com>
Date: Sun, 19 Jun 2022 02:51:22 -0700
Subject: [PATCH] GH-93990: fix refcounting bug in `add_subclass` in
 `typeobject.c` (GH-93989)

(cherry picked from commit 726448ebe15cd78e180c29c9858cb6c10a581524)

Co-authored-by: Kumar Aditya <59607654+kumaraditya303@users.noreply.github.com>
---
 Objects/typeobject.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index c1bae0b9a6d62f..d95b850699ed8e 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -6512,8 +6512,11 @@ add_subclass(PyTypeObject *base, PyTypeObject *type)
     PyObject *subclasses = base->tp_subclasses;
     if (subclasses == NULL) {
         base->tp_subclasses = subclasses = PyDict_New();
-        if (subclasses == NULL)
+        if (subclasses == NULL) {
+            Py_DECREF(key);
+            Py_DECREF(ref);
             return -1;
+        }
     }
     assert(PyDict_CheckExact(subclasses));