png_set_user_limits (png_structp png_ptr, png_uint_32 user_width_max,
    png_uint_32 user_height_max)
{
   /* Images with dimensions larger than these limits will be
    * rejected by png_set_IHDR().  To accept any PNG datastream
    * regardless of dimensions, set both limits to 0x7ffffffL.
    */
   if (png_ptr == NULL)
      return;
   png_ptr->user_width_max = user_width_max;
   png_ptr->user_height_max = user_height_max;
}

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.