[Python-checkins] closes bpo-38127: _ctypes: PyObject_IsSubclass() should be checked for failure. (GH-16011)

[Miss Islington (bot)]

https://github.com/python/cpython/commit/197ac1ad1c03243c647aa9100edbaa16bebbb7e9
commit: 197ac1ad1c03243c647aa9100edbaa16bebbb7e9
branch: 3.7
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: GitHub <noreply at github.com>
date: 2019-09-12T03:30:55-07:00
summary:

closes bpo-38127: _ctypes: PyObject_IsSubclass() should be checked for failure. (GH-16011)


An exception may occur during a PyObject_IsSubclass() call.
(cherry picked from commit ea683deccc505a78bbbb1eb8c6a88b0835ad5151)

Co-authored-by: Zackery Spytz <zspytz at gmail.com>

files:
M Modules/_ctypes/_ctypes.c

diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index 8008a481e275..f186e5082afb 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -1094,7 +1094,11 @@ PyCPointerType_from_param(PyObject *type, PyObject *value)
         */
         StgDictObject *v = PyObject_stgdict(value);
         assert(v); /* Cannot be NULL for pointer or array objects */
-        if (PyObject_IsSubclass(v->proto, typedict->proto)) {
+        int ret = PyObject_IsSubclass(v->proto, typedict->proto);
+        if (ret < 0) {
+            return NULL;
+        }
+        if (ret) {
             Py_INCREF(value);
             return value;
         }