bpo-34987: Fix a possible null pointer dereference in _pickle.c's save_reduce()....

(cherry picked from commit 25d389789c59a52a31770f7c50ce9e02a8909190)

Co-authored-by: Zackery Spytz <zspytz@gmail.com>

diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index a1a90bd95cae61bc6fc59f422a6a6fa1d216257f..57bb771addde904ede033e203a44551252b71c4d 100644 (file)
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -3838,7 +3838,10 @@ save_reduce(PicklerObject *self, PyObject *args, PyObject *obj)
 
         if (obj != NULL) {
             obj_class = get_class(obj);
-            p = obj_class != cls;    /* true iff a problem */
+            if (obj_class == NULL) {
+                return -1;
+            }
+            p = obj_class != cls;
             Py_DECREF(obj_class);
             if (p) {
                 PyErr_SetString(st->PicklingError, "args[0] from "