[3.11] gh-109216: Fix possible memory leak in BUILD_MAP (#109323)

* [3.11] gh-109216: Fix possible memory leak in `BUILD_MAP`

* Add NEWS

* Update Python/ceval.c

Co-authored-by: Kumar Aditya <[email protected]>

---------

Co-authored-by: Kumar Aditya <[email protected]>

Author: sobolevn

Misc/NEWS.d/next/Core and Builtins/2023-09-11-12-41-42.gh-issue-109216.60QOSb.rst

@@ -0,0 +1,2 @@
+Fix possible memory leak in :opcode:`BUILD_MAP`.
+

Python/ceval.c

@@ -3318,13 +3318,14 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
                     &PEEK(2*oparg), 2,
                     &PEEK(2*oparg - 1), 2,
                     oparg);
-            if (map == NULL)
-                goto error;
 
             while (oparg--) {
                 Py_DECREF(POP());
                 Py_DECREF(POP());
             }
+            if (map == NULL) {
+                goto error;
+            }
             PUSH(map);
             DISPATCH();
         }