From: Jelle Zijlstra <jelle.zijlstra@gmail.com>
Date: Fri, 30 May 2025 09:30:05 +0000 (-0700)
Subject: gh-134885: zstd: Use Py_XSETREF (GH-134886)
X-Git-Tag: v3.15.0a1~1451
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=45c6c48afc13f9897010e32171a3e02d0624258c;p=thirdparty%2FPython%2Fcpython.git

gh-134885: zstd: Use Py_XSETREF (GH-134886)
---

diff --git a/Misc/NEWS.d/next/Library/2025-05-29-06-53-40.gh-issue-134885.-_L22o.rst b/Misc/NEWS.d/next/Library/2025-05-29-06-53-40.gh-issue-134885.-_L22o.rst
new file mode 100644
index 000000000000..4b05d42c109d
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2025-05-29-06-53-40.gh-issue-134885.-_L22o.rst
@@ -0,0 +1,2 @@
+Fix possible crash in the :mod:`compression.zstd` module related to setting
+parameter types. Patch by Jelle Zijlstra.
diff --git a/Modules/_zstd/_zstdmodule.c b/Modules/_zstd/_zstdmodule.c
index 5ad697d2b83d..986b3579479f 100644
--- a/Modules/_zstd/_zstdmodule.c
+++ b/Modules/_zstd/_zstdmodule.c
@@ -514,13 +514,10 @@ _zstd_set_parameter_types_impl(PyObject *module, PyObject *c_parameter_type,
         return NULL;
     }
 
-    Py_XDECREF(mod_state->CParameter_type);
-    Py_INCREF(c_parameter_type);
-    mod_state->CParameter_type = (PyTypeObject*)c_parameter_type;
-
-    Py_XDECREF(mod_state->DParameter_type);
-    Py_INCREF(d_parameter_type);
-    mod_state->DParameter_type = (PyTypeObject*)d_parameter_type;
+    Py_XSETREF(
+        mod_state->CParameter_type, (PyTypeObject*)Py_NewRef(c_parameter_type));
+    Py_XSETREF(
+        mod_state->DParameter_type, (PyTypeObject*)Py_NewRef(d_parameter_type));
 
     Py_RETURN_NONE;
 }