  FT_Activate_Size( FT_Size  size )
  {
    FT_Face  face;


    if ( size == NULL )
      return FT_Err_Invalid_Argument;

    face = size->face;
    if ( face == NULL || face->driver == NULL )
      return FT_Err_Invalid_Argument;

    /* we don't need anything more complex than that; all size objects */
    /* are already listed by the face                                  */
    face->size = size;

    return FT_Err_Ok;
  }

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.