Red Hat file-sgi plugin: integer overflow

A flaw was found in the file-sgi plugin in GIMP. When processing an RLE-compressed SGI image, the plugin allocates memory for a row table. The image header dimensions (ysize and zsize) are read as 16-bit unsigned integers. If a crafted file sets both dimensions to their maximum value (65535), the multiplication ysize * zsize overflows the standard 32-bit int boundary before being passed to calloc. This integer overflow issue results in undefined behavior, aborting the plugin and causing a denial of service.