From e6ef47ac229b5c4a62b9c907e4232e350db77ce3 Mon Sep 17 00:00:00 2001
From: "Tomas R." <tomas.roun8@gmail.com>
Date: Fri, 11 Apr 2025 23:05:03 +0200
Subject: [PATCH] gh-132386: Fix a crash when passing a dict subclass to `exec`
 (GH-132412)

* Fix crash when passing a dict subclass to exec

* Add news entry
---
 Lib/test/test_compile.py                               | 10 ++++++++++
 .../2025-04-11-18-46-37.gh-issue-132386.pMBFTe.rst     |  2 ++
 Python/ceval.c                                         |  2 ++
 3 files changed, 14 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Core_and_Builtins/2025-04-11-18-46-37.gh-issue-132386.pMBFTe.rst

diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py
index ce9c060641d..9cc025d85e1 100644
--- a/Lib/test/test_compile.py
+++ b/Lib/test/test_compile.py
@@ -1636,6 +1636,16 @@ class TestSpecifics(unittest.TestCase):
                     pass
             [[]]
 
+    def test_globals_dict_subclass(self):
+        # gh-132386
+        class WeirdDict(dict):
+            pass
+
+        ns = {}
+        exec('def foo(): return a', WeirdDict(), ns)
+
+        self.assertRaises(NameError, ns['foo'])
+
 class TestBooleanExpression(unittest.TestCase):
     class Value:
         def __init__(self):
diff --git a/Misc/NEWS.d/next/Core_and_Builtins/2025-04-11-18-46-37.gh-issue-132386.pMBFTe.rst b/Misc/NEWS.d/next/Core_and_Builtins/2025-04-11-18-46-37.gh-issue-132386.pMBFTe.rst
new file mode 100644
index 00000000000..65ba7fc182b
--- /dev/null
+++ b/Misc/NEWS.d/next/Core_and_Builtins/2025-04-11-18-46-37.gh-issue-132386.pMBFTe.rst
@@ -0,0 +1,2 @@
+Fix crash when passing a dict subclass as the ``globals`` parameter to
+:func:`exec`.
diff --git a/Python/ceval.c b/Python/ceval.c
index 8ab0c6318c1..e4a63ad9287 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -3312,6 +3312,8 @@ _PyEval_LoadGlobalStackRef(PyObject *globals, PyObject *builtins, PyObject *name
                 _PyEval_FormatExcCheckArg(
                             PyThreadState_GET(), PyExc_NameError,
                             NAME_ERROR_MSG, name);
+                *writeto = PyStackRef_NULL;
+                return;
             }
         }
         *writeto = PyStackRef_FromPyObjectSteal(res);