From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Sun, 11 Jun 2023 20:30:47 +0000 (-0700)
Subject: [3.11] gh-105375: Improve error handling in _ctypes (GH-105593) (#105664)
X-Git-Tag: v3.11.5~286
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=a03449374ebd5bffe54d3e09d36b54bc605551d8;p=thirdparty%2FPython%2Fcpython.git

[3.11] gh-105375: Improve error handling in _ctypes (GH-105593) (#105664)

Prevent repeated PyLong_FromVoidPtr() from possibly overwriting the
current exception.
(cherry picked from commit e8998e46a7ce8ad336e0941a6da6e50cb88d1e47)

Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com>
---

diff --git a/Misc/NEWS.d/next/Library/2023-06-09-21-40-45.gh-issue-105375._sZilh.rst b/Misc/NEWS.d/next/Library/2023-06-09-21-40-45.gh-issue-105375._sZilh.rst
new file mode 100644
index 000000000000..87db4c2b4e22
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2023-06-09-21-40-45.gh-issue-105375._sZilh.rst
@@ -0,0 +1 @@
+Fix bugs in :mod:`_ctypes` where exceptions could end up being overwritten.
diff --git a/Modules/_ctypes/callbacks.c b/Modules/_ctypes/callbacks.c
index b46067bf2fa6..e2dc2d23317f 100644
--- a/Modules/_ctypes/callbacks.c
+++ b/Modules/_ctypes/callbacks.c
@@ -499,12 +499,22 @@ long Call_GetClassObject(REFCLSID rclsid, REFIID riid, LPVOID *ppv)
 
     {
         PyObject *py_rclsid = PyLong_FromVoidPtr((void *)rclsid);
+        if (py_rclsid == NULL) {
+            Py_DECREF(func);
+            PyErr_WriteUnraisable(context ? context : Py_None);
+            return E_FAIL;
+        }
         PyObject *py_riid = PyLong_FromVoidPtr((void *)riid);
+        if (py_riid == NULL) {
+            Py_DECREF(func);
+            Py_DECREF(py_rclsid);
+            PyErr_WriteUnraisable(context ? context : Py_None);
+            return E_FAIL;
+        }
         PyObject *py_ppv = PyLong_FromVoidPtr(ppv);
-        if (!py_rclsid || !py_riid || !py_ppv) {
-            Py_XDECREF(py_rclsid);
-            Py_XDECREF(py_riid);
-            Py_XDECREF(py_ppv);
+        if (py_ppv == NULL) {
+            Py_DECREF(py_rclsid);
+            Py_DECREF(py_riid);
             Py_DECREF(func);
             PyErr_WriteUnraisable(context ? context : Py_None);
             return E_FAIL;