fix possible double free in TextIOWrapper.__init__ (closes #22849)

Lib/test/test_io.py

@@ -2784,6 +2784,21 @@ class TextIOWrapperTest(unittest.TestCase):
         self.assertFalse(err)
         self.assertEqual("ok", out.decode().strip())
 
+    def test_issue22849(self):
+        class F(object):
+            def readable(self): return True
+            def writable(self): return True
+            def seekable(self): return True
+
+        for i in range(10):
+            try:
+                self.TextIOWrapper(F(), encoding='utf-8')
+            except Exception:
+                pass
+
+        F.tell = lambda x: 0
+        t = self.TextIOWrapper(F(), encoding='utf-8')
+
 
 class CTextIOWrapperTest(TextIOWrapperTest):
     io = io

Misc/NEWS

@@ -36,6 +36,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #22849: Fix possible double free in the io.TextIOWrapper constructor.
+
 - Issue #12728: Different Unicode characters having the same uppercase but
   different lowercase are now matched in case-insensitive regular expressions.
 

Modules/_io/textio.c

@@ -1061,7 +1061,7 @@ textiowrapper_init(textio *self, PyObject *args, PyObject *kwds)
     }
 
     /* Finished sorting out the codec details */
-    Py_DECREF(codec_info);
+    Py_CLEAR(codec_info);
 
     self->buffer = buffer;
     Py_INCREF(buffer);