bpo-40559: Add Py_DECREF to _asynciomodule.c:task_step_impl() (GH-19990)

cjerdonek · web-flow · commit d2c349b190bc · 2020-05-08T03:54:38.000-07:00
This fixes a possible memory leak in the C implementation of
asyncio.Task.
diff --git a/Misc/NEWS.d/next/Library/2020-05-05-08-12-51.bpo-40559.112wwa.rst b/Misc/NEWS.d/next/Library/2020-05-05-08-12-51.bpo-40559.112wwa.rst
@@ -0,0 +1 @@
+Fix possible memory leak in the C implementation of :class:`asyncio.Task`.
diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c
@@ -2638,6 +2638,10 @@ task_step_impl(TaskObj *task, PyObject *exc)
     coro = task->task_coro;
     if (coro == NULL) {
         PyErr_SetString(PyExc_RuntimeError, "uninitialized Task object");
+        if (clear_exc) {
+            /* We created 'exc' during this call */
+            Py_DECREF(exc);
+        }
         return NULL;
     }
 

Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+Fix possible memory leak in the C implementation of :class:`asyncio.Task`.