From f9169ce6b48c7cc7cc62d9eb5e4ee1ac7066d14b Mon Sep 17 00:00:00 2001 From: Thomas Kluyver Date: Tue, 23 May 2017 04:27:52 +0100 Subject: bpo-25532: Protect against infinite loops in inspect.unwrap() (#1717) Some objects (like test mocks) auto-generate new objects on attribute access, which can lead to an infinite loop in inspect.unwrap(). Ensuring references are retained to otherwise temporary objects and capping the size of the memo dict turns this case into a conventional exception instead. --- Lib/test/test_inspect.py | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) (limited to 'Lib/test') diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py index c55efd6942..350d5dbd77 100644 --- a/Lib/test/test_inspect.py +++ b/Lib/test/test_inspect.py @@ -3554,6 +3554,19 @@ class TestSignatureDefinitions(unittest.TestCase): self.assertIsNone(obj.__text_signature__) +class NTimesUnwrappable: + def __init__(self, n): + self.n = n + self._next = None + + @property + def __wrapped__(self): + if self.n <= 0: + raise Exception("Unwrapped too many times") + if self._next is None: + self._next = NTimesUnwrappable(self.n - 1) + return self._next + class TestUnwrap(unittest.TestCase): def test_unwrap_one(self): @@ -3609,6 +3622,11 @@ class TestUnwrap(unittest.TestCase): __wrapped__ = func self.assertIsNone(inspect.unwrap(C())) + def test_recursion_limit(self): + obj = NTimesUnwrappable(sys.getrecursionlimit() + 1) + with self.assertRaisesRegex(ValueError, 'wrapper loop'): + inspect.unwrap(obj) + class TestMain(unittest.TestCase): def test_only_source(self): module = importlib.import_module('unittest') -- cgit v1.2.1