From: Serhiy Storchaka <storchaka@gmail.com>
Date: Thu, 5 Jul 2018 09:20:19 +0000 (+0300)
Subject: [2.7] bpo-33720: Improve tests for the stack overflow in marshal.loads(). (GH-7336... 
X-Git-Tag: v2.7.16rc1~216
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9720f60f2aba457121bfe42d09aa3ed91f28b86f;p=thirdparty%2FPython%2Fcpython.git

[2.7] bpo-33720: Improve tests for the stack overflow in marshal.loads(). (GH-7336). (GH-8107)

(cherry picked from commit fc05e68d8fac70349b7ea17ec14e7e0cfa956121)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
---

diff --git a/Lib/test/test_marshal.py b/Lib/test/test_marshal.py
index 76d59bac392a..bbaa9442ab76 100644
--- a/Lib/test/test_marshal.py
+++ b/Lib/test/test_marshal.py
@@ -227,8 +227,22 @@ class BugsTestCase(unittest.TestCase):
                 pass
 
     def test_loads_recursion(self):
-        s = 'c' + ('X' * 4*4) + '{' * 2**20
-        self.assertRaises(ValueError, marshal.loads, s)
+        def run_tests(N, check):
+            # (((...None...),),)
+            check(b'(\x01\x00\x00\x00' * N + b'N')
+            # [[[...None...]]]
+            check(b'[\x01\x00\x00\x00' * N + b'N')
+            # {None: {None: {None: ...None...}}}
+            check(b'{N' * N + b'N' + b'0' * N)
+            # frozenset([frozenset([frozenset([...None...])])])
+            check(b'>\x01\x00\x00\x00' * N + b'N')
+        # Check that the generated marshal data is valid and marshal.loads()
+        # works for moderately deep nesting
+        run_tests(100, marshal.loads)
+        # Very deeply nested structure shouldn't blow the stack
+        def check(s):
+            self.assertRaises(ValueError, marshal.loads, s)
+        run_tests(2**20, check)
 
     def test_recursion_limit(self):
         # Create a deeply nested structure.