inspect: Validate that __signature__ is None or an instance of Signature.
Closes #21801.
diff --git a/Lib/inspect.py b/Lib/inspect.py
index 4c3e33d..f6e1b47 100644
--- a/Lib/inspect.py
+++ b/Lib/inspect.py
@@ -1912,6 +1912,10 @@
pass
else:
if sig is not None:
+ if not isinstance(sig, Signature):
+ raise TypeError(
+ 'unexpected object {!r} in __signature__ '
+ 'attribute'.format(sig))
return sig
try:
diff --git a/Lib/test/test_inspect.py b/Lib/test/test_inspect.py
index 1ede3b5..da0572d 100644
--- a/Lib/test/test_inspect.py
+++ b/Lib/test/test_inspect.py
@@ -3048,6 +3048,13 @@
self.assertEqual(lines[:-1], inspect.getsource(module).splitlines())
self.assertEqual(err, b'')
+ def test_custom_getattr(self):
+ def foo():
+ pass
+ foo.__signature__ = 42
+ with self.assertRaises(TypeError):
+ inspect.signature(foo)
+
@unittest.skipIf(ThreadPoolExecutor is None,
'threads required to test __qualname__ for source files')
def test_qualname_source(self):
diff --git a/Misc/NEWS b/Misc/NEWS
index 128937e..52c1e0e 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -105,6 +105,8 @@
- Issue #21538: The plistlib module now supports loading of binary plist files
when reference or offset size is not a power of two.
+- Issue #21801: Validate that __signature__ is None or an instance of Signature.
+
Build
-----