Issue #16445: Fix potential segmentation fault when deleting an exception message.
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index 2160641..a485cba 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -479,6 +479,18 @@
except AssertionError as e:
self.assertEqual(str(e), "(3,)")
+ def test_bad_exception_clearing(self):
+ # See issue 16445: use of Py_XDECREF instead of Py_CLEAR in
+ # BaseException_set_message gave a possible way to segfault the
+ # interpreter.
+ class Nasty(str):
+ def __del__(message):
+ del e.message
+
+ e = ValueError(Nasty("msg"))
+ e.args = ()
+ del e.message
+
# Helper class used by TestSameStrAndUnicodeMsg
class ExcWithOverriddenStr(Exception):
diff --git a/Misc/NEWS b/Misc/NEWS
index 78d52f0..4f6fdca 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -9,6 +9,9 @@
Core and Builtins
-----------------
+- Issue #16445: Fixed potential segmentation fault when deleting an exception
+ message.
+
- Issue #17275: Corrected class name in init error messages of the C version of
BufferedWriter and BufferedRandom.
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index 49f6d30..0f86cfb 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -349,8 +349,7 @@
if (PyDict_DelItemString(self->dict, "message") < 0)
return -1;
}
- Py_XDECREF(self->message);
- self->message = NULL;
+ Py_CLEAR(self->message);
return 0;
}