gh-143544: Fix possible use-after-free in the JSON decoder when JSONDecodeError disap...

Co-authored-by: Bénédikt Tran <10796600+picnixz@users.noreply.github.com>

diff --git a/Modules/_json.c b/Modules/_json.c
index 14714d4b346546d86b874c8d962b43c94d0233da..78a85496575a2cf94be4ace09b6fcb78bd7a4efc 100644 (file)
--- a/Modules/_json.c
+++ b/Modules/_json.c
@@ -423,11 +423,12 @@ raise_errmsg(const char *msg, PyObject *s, Py_ssize_t end)
 
     PyObject *exc;
     exc = PyObject_CallFunction(JSONDecodeError, "zOn", msg, s, end);
-    Py_DECREF(JSONDecodeError);
     if (exc) {
         PyErr_SetObject(JSONDecodeError, exc);
         Py_DECREF(exc);
     }
+
+    Py_DECREF(JSONDecodeError);
 }
 
 static void