3 files changed, 17 insertions, 1 deletions
diff --git a/Lib/test/test_importlib/import_/test_relative_imports.py b/Lib/test/test_importlib/import_/test_relative_imports.py
index e535d119763..1549cbe96ce 100644
--- a/Lib/test/test_importlib/import_/test_relative_imports.py
+++ b/Lib/test/test_importlib/import_/test_relative_imports.py
@@ -223,6 +223,21 @@ class RelativeImports:
             self.__import__('sys', {'__package__': '', '__spec__': None},
                             level=1)
 
+    def test_malicious_relative_import(self):
+        # https://github.com/python/cpython/issues/134100
+        # Test to make sure UAF bug with error msg doesn't come back to life
+        import sys
+        loooong = "".ljust(0x23000, "b")
+        name = f"a.{loooong}.c"
+
+        with util.uncache(name):
+            sys.modules[name] = {}
+            with self.assertRaisesRegex(
+                KeyError,
+                r"'a\.b+' not in sys\.modules as expected"
+            ):
+                __import__(f"{loooong}.c", {"__package__": "a"}, level=1)
+
 
 (Frozen_RelativeImports,
  Source_RelativeImports
diff --git a/Lib/test/test_importlib/test_locks.py b/Lib/test/test_importlib/test_locks.py
index befac5d62b0..655e5881a15 100644
--- a/Lib/test/test_importlib/test_locks.py
+++ b/Lib/test/test_importlib/test_locks.py
@@ -34,6 +34,7 @@ class ModuleLockAsRLockTests:
     # lock status in repr unsupported
     test_repr = None
     test_locked_repr = None
+    test_repr_count = None
 
     def tearDown(self):
         for splitinit in init.values():
diff --git a/Lib/test/test_importlib/test_util.py b/Lib/test/test_importlib/test_util.py
index 5de89714eb5..6d6d5f96aab 100644
--- a/Lib/test/test_importlib/test_util.py
+++ b/Lib/test/test_importlib/test_util.py
@@ -635,7 +635,7 @@ class MagicNumberTests(unittest.TestCase):
         # stakeholders such as OS package maintainers must be notified
         # in advance. Such exceptional releases will then require an
         # adjustment to this test case.
-        EXPECTED_MAGIC_NUMBER = 3495
+        EXPECTED_MAGIC_NUMBER = 3625
         actual = int.from_bytes(importlib.util.MAGIC_NUMBER[:2], 'little')
 
         msg = (