From e420d032d334192ace884ee60310afd862af1cd2 Mon Sep 17 00:00:00 2001
From: Fidget-Spinner <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Sat, 29 Jan 2022 15:24:16 +0800
Subject: [PATCH] fix refleak in isinstance error path

---
 Python/ceval.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Python/ceval.c b/Python/ceval.c
index fa14a1c04f1e0c..b69d5aa9d32069 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -4946,6 +4946,7 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, InterpreterFrame *frame, int thr
             PyObject *inst = TOP();
             int retval = PyObject_IsInstance(inst, cls);
             if (retval < 0) {
+                Py_DECREF(cls);
                 goto error;
             }
             PyObject *res = PyBool_FromLong(retval);