From: utzoo!decvax!harpo!seismo!hao!hplabs!sri-unix!Michael.Young.CMU-CS-A@SRI-UNIX
Newsgroups: net.unix-wizards
Title: Re: protecting kmem because someone felt obnoxious.
Article-I.D.: sri-unix.4961
Posted: Wed Dec 29 00:07:32 1982
Received: Thu Dec 30 04:52:20 1982

From: Michael Wayne Young <Michael.Young.CMU-CS-A@SRI-UNIX>
Date: 23 December 1982 0112-EST (Thursday)
Yes, I think /dev/kmem was meant to be readable, but only by root.
Not only do you get i/o queues, but anything the kernel might ever
consider privileged information -- including user text/data spaces.
If you want to let non-root users read /dev/kmem (or /dev/mem, or even
raw devices, but that's another matter), you can easily let a
"privileged" group own them, let the group members read them, and
make any of that list of programs be setgid.  [This reduces to trusting
this "privileged" group to not giving away their privileges, but
I find that much more reasonable.  It has worked on the systems I've
run, and here at CMU, where I am not privileged, but don't miss it all
that much.]  Note that you also have less setuid-root programs that
might break.

As an aside, I think that a careful system administrator can make
a Unix system much more secure than RSTS, or the myriad of
other Dec operating systems, because of the more coherent design
of Unix privileges.  [Not perfect -- there are lots of ways to
easily screw up -- it's just easier to spot bugs and fix them fast.]

Also, I think that Unix is no more immune to malicious users than other systems.
>From my experience, troublesome users are fairly evenly distributed
among the available resources.

Wishing we'd all think more seriously about security (myself included),

			Michael