Issue #25021: Correctly make sure that product.__setstate__ does not access

invalid memory.

1 files changed, 10 insertions, 0 deletions

diff --git a/Lib/test/test_itertools.py b/Lib/test/test_itertools.py
index bb3b61f..35391c9 100644
--- a/Lib/test/test_itertools.py
+++ b/Lib/test/test_itertools.py
@@ -959,6 +959,16 @@ class TestBasicOps(unittest.TestCase):
             self.assertEqual(list(copy.deepcopy(product(*args))), result)
             self.pickletest(product(*args))
 
+    def test_product_issue_25021(self):
+        # test that indices are properly clamped to the length of the tuples
+        p = product((1, 2),(3,))
+        p.__setstate__((0, 0x1000))  # will access tuple element 1 if not clamped
+        self.assertEqual(next(p), (2, 3))
+        # test that empty tuple in the list will result in an immediate StopIteration
+        p = product((1, 2), (), (3,))
+        p.__setstate__((0, 0, 0x1000))  # will access tuple element 1 if not clamped
+        self.assertRaises(StopIteration, next, p)
+
     def test_repeat(self):
         self.assertEqual(list(repeat(object='a', times=3)), ['a', 'a', 'a'])
         self.assertEqual(lzip(range(3),repeat('a')),