--- a/src/radius/radius.c
+++ b/src/radius/radius.c
@@ -755,7 +755,7 @@ struct radius_attr_hdr * radius_msg_add_
 			ext->length = sizeof(*ext) + 1 + alen;
 			ext->ext_type = ext_type;
 			wpabuf_put_u8(msg->buf, data_len > alen ? 0x80 : 0);
-			wpabuf_put_data(msg->buf, data, data_len);
+			wpabuf_put_data(msg->buf, data, alen);
 			data += alen;
 			data_len -= alen;
 			if (radius_msg_add_attr_to_array(