Issue #24683: Fixed crashes in _json functions called with arguments of

inappropriate type.

1 files changed, 10 insertions, 2 deletions

diff --git a/Modules/_json.c b/Modules/_json.c
index 8000f915f3..f63d758348 100644
--- a/Modules/_json.c
+++ b/Modules/_json.c
@@ -1344,11 +1344,19 @@ encoder_init(PyObject *self, PyObject *args, PyObject *kwds)
     assert(PyEncoder_Check(self));
     s = (PyEncoderObject *)self;
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwds, "OOOOOOOOp:make_encoder", kwlist,
-        &markers, &defaultfn, &encoder, &indent, &key_separator, &item_separator,
+    if (!PyArg_ParseTupleAndKeywords(args, kwds, "OOOOUUOOp:make_encoder", kwlist,
+        &markers, &defaultfn, &encoder, &indent,
+        &key_separator, &item_separator,
         &sort_keys, &skipkeys, &allow_nan))
         return -1;
 
+    if (markers != Py_None && !PyDict_Check(markers)) {
+        PyErr_Format(PyExc_TypeError,
+                     "make_encoder() argument 1 must be dict or None, "
+                     "not %.200s", Py_TYPE(markers)->tp_name);
+        return -1;
+    }
+
     s->markers = markers;
     s->defaultfn = defaultfn;
     s->encoder = encoder;