Backport python#122834 for 3.13

Author: ZeroIntensity

Misc/NEWS.d/next/Library/2024-08-08-15-05-58.gh-issue-122695.f7pwBv.rst

@@ -0,0 +1,2 @@
+Fixed double-free when using :func:`gc.get_referents` with a freed
+:class:`asyncio.Future` iterator.

Modules/_asynciomodule.c

@@ -3530,16 +3530,8 @@ module_traverse(PyObject *mod, visitproc visit, void *arg)
 
     Py_VISIT(state->context_kwname);
 
-#ifndef Py_GIL_DISABLED
-    // Visit freelist.
-    PyObject *next = (PyObject*) state->fi_freelist;
-    while (next != NULL) {
-        PyObject *current = next;
-        Py_VISIT(current);
-        next = (PyObject*) ((futureiterobject*) current)->future;
-    }
-#endif
-
+    // GH-122695: Do not traverse the freelist here, as that can cause problems
+    // with gc.get_referents()
     return 0;
 }