From owner-freebsd-hackers  Wed Aug  7 14:41:53 1996
Return-Path: owner-hackers
Received: (from root@localhost)
          by freefall.freebsd.org (8.7.5/8.7.3) id OAA10892
          for hackers-outgoing; Wed, 7 Aug 1996 14:41:53 -0700 (PDT)
Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.19])
          by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id OAA10883
          for <Hackers@FreeBSD.ORG>; Wed, 7 Aug 1996 14:41:47 -0700 (PDT)
Received: (from bde@localhost) by godzilla.zeta.org.au (8.6.12/8.6.9) id HAA05066; Thu, 8 Aug 1996 07:38:59 +1000
Date: Thu, 8 Aug 1996 07:38:59 +1000
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199608072138.HAA05066@godzilla.zeta.org.au>
To: jds@TracerTech.COM, michaelh@cet.co.jp
Subject: Re: kern_mib.c:int securelevel = -1;
Cc: Hackers@FreeBSD.ORG
Sender: owner-hackers@FreeBSD.ORG
X-Loop: FreeBSD.org
Precedence: bulk

> > #ifdef INSECURE
> > int securelevel = -1
> > #else
> > int securelevel
> > #endif
> > 
> > Here's the a comment from <sys/systm.h> ...

>By the way, the comment is wrong on one important point: the disposition of
>this variable in bss vs data will be irrelevant to a cracker.  If the
>kernel is not immutable, the variable can be patched either way.

Not quite.  The point is to patch the kernel that will be booted from.
However if the kernel is not immutable, a cracker could patch some of
the code that tests the variable.

Bruce