From b3f8754c8a0c743e9f80c06472ec7a7adc96f438 Mon Sep 17 00:00:00 2001
From: JustAnotherArchivist <JustAnotherArchivist@users.noreply.github.com>
Date: Sun, 17 Apr 2022 04:04:40 +0000
Subject: [PATCH] Fix segmentation faults when handling unserialisable objects

Errors during `__repr__` itself as well as ones during the conversion to a bytes object were not handled, resulting in NULL pointer dereferencing.

Cf. #382
---
 python/objToJSON.c  | 11 +++++++++--
 tests/test_ujson.py | 15 ++++++++++++---
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/python/objToJSON.c b/python/objToJSON.c
index d7f6cb92..7d0076d9 100644
--- a/python/objToJSON.c
+++ b/python/objToJSON.c
@@ -670,8 +670,15 @@ static void Object_beginTypeContext (JSOBJ _obj, JSONTypeContext *tc, JSONObject
   PyErr_Clear();
 
   objRepr = PyObject_Repr(obj);
-  PyObject* str = PyUnicode_AsEncodedString(objRepr, "utf-8", "~E~");
-  PyErr_Format (PyExc_TypeError, "%s is not JSON serializable", PyBytes_AsString(str));
+  if (!objRepr)
+  {
+    goto INVALID;
+  }
+  PyObject* str = PyUnicode_AsEncodedString(objRepr, "utf-8", "strict");
+  if (str)
+  {
+    PyErr_Format (PyExc_TypeError, "%s is not JSON serializable", PyBytes_AsString(str));
+  }
   Py_XDECREF(str);
   Py_DECREF(objRepr);
 
diff --git a/tests/test_ujson.py b/tests/test_ujson.py
index 3e3f3f1b..9c40b97b 100644
--- a/tests/test_ujson.py
+++ b/tests/test_ujson.py
@@ -636,8 +636,14 @@ def test_dumps(test_input, expected):
 
 
 class SomeObject:
+    def __init__(self, message, exception=None):
+        self._message = message
+        self._exception = exception
+
     def __repr__(self):
-        return "Some Object"
+        if self._exception:
+            raise self._exception
+        return self._message
 
 
 @pytest.mark.parametrize(
@@ -645,13 +651,16 @@ def __repr__(self):
     [
         (set(), TypeError, "set() is not JSON serializable"),
         ({1, 2, 3}, TypeError, "{1, 2, 3} is not JSON serializable"),
-        (SomeObject(), TypeError, "Some Object is not JSON serializable"),
+        (SomeObject("Some Object"), TypeError, "Some Object is not JSON serializable"),
+        (SomeObject("\ud800"), UnicodeEncodeError, None),
+        (SomeObject(None, KeyboardInterrupt), KeyboardInterrupt, None),
     ],
 )
 def test_dumps_raises(test_input, expected_exception, expected_message):
     with pytest.raises(expected_exception) as e:
         ujson.dumps(test_input)
-    assert str(e.value) == expected_message
+    if expected_message:
+        assert str(e.value) == expected_message
 
 
 @pytest.mark.parametrize(