gh-126991: Fix reference leak in loading pickle's opcode BUILD (GH-126990)

If PyObject_SetItem() fails in the `load_build()` function of _pickle.c, no DECREF for the `dict` variable.

diff --git a/Modules/_pickle.c b/Modules/_pickle.c
index 5837cd41a40cd4893295d666a3f4fcfcb54c59e6..2696f38046121f1d91069b7801e870602d6595ec 100644 (file)
--- a/Modules/_pickle.c
+++ b/Modules/_pickle.c
@@ -6730,6 +6730,7 @@ load_build(PickleState *st, UnpicklerObject *self)
             }
             if (PyObject_SetItem(dict, d_key, d_value) < 0) {
                 Py_DECREF(d_key);
+                Py_DECREF(dict);
                 goto error;
             }
             Py_DECREF(d_key);