Issue #14471: Fix a possible buffer overrun in the winreg module.

Misc/NEWS

@@ -34,6 +34,8 @@ Core and Builtins
 - Issue #13521: dict.setdefault() now does only one lookup for the given key,
   making it "atomic" for many purposes.  Patch by Filip Gruszczyński.
 
+- Issue #14471: Fix a possible buffer overrun in the winreg module.
+
 Library
 -------
 

PC/winreg.c

@@ -1110,7 +1110,7 @@ PyEnumKey(PyObject *self, PyObject *args)
      * nul.  RegEnumKeyEx requires a 257 character buffer to
      * retrieve such a key name. */
     wchar_t tmpbuf[257];
-    DWORD len = sizeof(tmpbuf); /* includes NULL terminator */
+    DWORD len = sizeof(tmpbuf)/sizeof(wchar_t); /* includes NULL terminator */
 
     if (!PyArg_ParseTuple(args, "Oi:EnumKey", &obKey, &index))
         return NULL;