Issue #24467: Fixed possible buffer over-read in bytearray. The bytearray

object now always allocates place for trailing null byte and it's buffer now
is always null-terminated.

1 files changed, 3 insertions, 1 deletions

diff --git a/Objects/bytearrayobject.c b/Objects/bytearrayobject.c
index 2e47a1c47c..15c525c442 100644
--- a/Objects/bytearrayobject.c
+++ b/Objects/bytearrayobject.c
@@ -854,8 +854,10 @@ bytearray_init(PyByteArrayObject *self, PyObject *args, PyObject *kwds)
             goto error;
 
         /* Append the byte */
-        if (Py_SIZE(self) < self->ob_alloc)
+        if (Py_SIZE(self) + 1 < self->ob_alloc) {
             Py_SIZE(self)++;
+            PyByteArray_AS_STRING(self)[Py_SIZE(self)] = '\0';
+        }
         else if (PyByteArray_Resize((PyObject *)self, Py_SIZE(self)+1) < 0)
             goto error;
         PyByteArray_AS_STRING(self)[Py_SIZE(self)-1] = value;