[comp.sys.alliant] setgid kmem executables -> permission denied?

kinzler@iuvax.cs.indiana.edu (Steve Kinzler) (05/28/91)

In an attempt to improve security on our Alliant FX/8 running Concentrix
5.0.0, I wanted to make /dev/kmem and /dev/mem not world-readable.

So I made a group kmem (gid 6), found the system programs that need to
read /dev/*mem, made them all setgid kmem, and made /dev/*mem owned by
group kmem.

But, when I "chmod o-r /dev/*mem", I find that ordinary users can't run
these system programs (such as /bin/ps, /bin/mon, etc).  They get
"Permission denied".

Am I missing something fundamental here, or is this a quirk of
Concentrix?  I've done this on other varients of Unix with success.

Thanks for any help,				Steve Kinzler
						Sys Admin IU Comp Sci