shred: bug or feature? think you should know about it

[Anton Chuvakin, Ph.D.]

when shred runs, the slack space is not wiped:

0. # shred --version
shred (fileutils) 4.1
1. # mkfs -t ext2 /dev/fd0
2. # dd if=/dev/zero of=/mnt/floppy/oooo ; sync ; /bin/rm /mnt/floppy/oooo ; 
sync
3. # mount /mnt/floppy
4. # echo "good data" > /mnt/floppy/TEST
5. # echo "evil data" | bmap --mode putslack /mnt/floppy/TEST
6. # strings /dev/fd0 | grep data
good data
evil data
7. # shred -u -v -z /mnt/floppy/TEST
8. # strings /dev/fd0 | grep data
evil data

-- 
Anton Chuvakin, Ph.D.
Senior Security Analyst 
netForensics -  http://www.netforensics.com
732-393-6071