From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Fri, 17 Mar 2023 14:54:18 +0000 (-0700)
Subject: gh-102701: Fix overflow in dictobject.c (GH-102750)
X-Git-Tag: v3.11.3~49
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=f967aee4fbb9f417028426568230e2091d95f0fe;p=thirdparty%2FPython%2Fcpython.git

gh-102701: Fix overflow in dictobject.c (GH-102750)

(cherry picked from commit 65fb7c4055f280caaa970939d16dd947e6df8a8d)

Co-authored-by: Inada Naoki <songofacandy@gmail.com>
---

diff --git a/Lib/test/test_bigmem.py b/Lib/test/test_bigmem.py
index 859f1539e20b..c9ab1c1de9e1 100644
--- a/Lib/test/test_bigmem.py
+++ b/Lib/test/test_bigmem.py
@@ -1248,6 +1248,15 @@ class ListTest(unittest.TestCase):
         self.assertEqual(l[-10:], [5] * 10)
 
 
+class DictTest(unittest.TestCase):
+
+    @bigmemtest(size=357913941, memuse=160)
+    def test_dict(self, size):
+        # https://github.com/python/cpython/issues/102701
+        d = dict.fromkeys(range(size))
+        d[size] = 1
+
+
 if __name__ == '__main__':
     if len(sys.argv) > 1:
         support.set_memlimit(sys.argv[1])
diff --git a/Misc/NEWS.d/next/Core and Builtins/2023-03-16-17-24-44.gh-issue-102701.iNGVaS.rst b/Misc/NEWS.d/next/Core and Builtins/2023-03-16-17-24-44.gh-issue-102701.iNGVaS.rst
new file mode 100644
index 000000000000..4e1f31893377
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2023-03-16-17-24-44.gh-issue-102701.iNGVaS.rst	
@@ -0,0 +1 @@
+Fix overflow when creating very large dict.
diff --git a/Objects/dictobject.c b/Objects/dictobject.c
index 4a214f8cf5b7..69a4a865103c 100644
--- a/Objects/dictobject.c
+++ b/Objects/dictobject.c
@@ -600,7 +600,7 @@ new_keys_object(uint8_t log2_size, bool unicode)
 
     assert(log2_size >= PyDict_LOG_MINSIZE);
 
-    usable = USABLE_FRACTION(1<<log2_size);
+    usable = USABLE_FRACTION((size_t)1<<log2_size);
     if (log2_size < 8) {
         log2_bytes = log2_size;
     }