[3.8] gh-97616: list_resize() checks for integer overflow (GH-97617) (GH-97628)

gh-97616: list_resize() checks for integer overflow (GH-97617)

Fix multiplying a list by an integer (list *= int): detect the
integer overflow when the new allocated length is close to the
maximum size.  Issue reported by Jordan Limor.

list_resize() now checks for integer overflow before multiplying the
new allocated length by the list item size (sizeof(PyObject*)).
(cherry picked from commit a5f092f3c469b674b8d9ccbd4e4377230c9ac7cf)

Co-authored-by: Victor Stinner <vstinner@python.org>

1 files changed, 13 insertions, 0 deletions

diff --git a/Lib/test/test_list.py b/Lib/test/test_list.py
index 105ef650ee..75ecc70b0b 100644
--- a/Lib/test/test_list.py
+++ b/Lib/test/test_list.py
@@ -68,6 +68,19 @@ class ListTest(list_tests.CommonTest):
         self.assertRaises((MemoryError, OverflowError), mul, lst, n)
         self.assertRaises((MemoryError, OverflowError), imul, lst, n)
 
+    def test_list_resize_overflow(self):
+        # gh-97616: test new_allocated * sizeof(PyObject*) overflow
+        # check in list_resize()
+        lst = [0] * 65
+        del lst[1:]
+        self.assertEqual(len(lst), 1)
+
+        size = ((2 ** (tuple.__itemsize__ * 8) - 1) // 2)
+        with self.assertRaises((MemoryError, OverflowError)):
+            lst * size
+        with self.assertRaises((MemoryError, OverflowError)):
+            lst *= size
+
     def test_repr_large(self):
         # Check the repr of large list objects
         def check(n):