https://github.com/python/cpython/commit/8fb36494501aad5b0c1d34311c9743c60bb... commit: 8fb36494501aad5b0c1d34311c9743c60bb9926c branch: main author: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com> committer: pablogsal <Pablogsal@gmail.com> date: 2022-01-29T14:34:12Z summary: fFx refleak in isinstance error path (GH-31005) files: M Python/ceval.c diff --git a/Python/ceval.c b/Python/ceval.c index fa14a1c04f1e0..b69d5aa9d3206 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);