Subject: bug#23498: grub2 gzio suffers from output buffer overrun when unzipping fdubcd.img.gz

From: Elmar Stellnberger <[email-masked]>
Date: Mon, 9 May 2016 22:59:45 +0200

Package: grub
    Version: 1:2.02.beta2

See for the buffer overrun message at:
http://elstel.rivido.de/uploads/grub-gzio/screenshot.jpeg

The respective .gz file which can not be unpacked is:
http://elstel.rivido.de/uploads/grub-gzio/fdubcd.img.gz

The following menuentry produces the gzip buffer overrun:

   menuentry 'FreeDOS' {
     insmod gzio
     insmod memdisk
     linux16 (hd0,msdos18)/boot/syslinux/memdisk
     initrd16 (hd0,msdos18)/ubcd/images/fdubcd.img.gz
   }

A similar syslinux entry works fine:

LABEL -
MENU LABEL UBCD FreeDOS R1.52 (Based on NwDsk V3.40)
TEXT HELP
  FreeDOS boot disk used to run many of the other DOS apps on the UBCD. 
Revised
  version of Eric Veermans' FreeDOS NwDsk 3.40. Addresses many bug fixes,
  performance enhancements and compatibility issues.
ENDTEXT
COM32 linux.c32 memdisk
INITRD /ubcd/images/fdubcd.img.gz