From owner-freebsd-security  Tue Jul  2 03:46:37 1996
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Date: Tue, 2 Jul 1996 05:49:46 -0500
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From: Alex Nash <alex@orion.fa.tdktca.com>
To: zbs@softec.softec.sk
Cc: freebsd-security@freebsd.org
Subject: Re: securelevel and modload
Reply-to: alex@fa.tdktca.com
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> I think the FreeBSD kernel securelevel functionality together with
> the schg and sappnd flags are a very good idea to make systems
> more secure. I like the idea of unchangable securelevel,
> unchangable flags etc. But I don't know whether this
> all securelevel stuff can be eliminated by a 
> loadable kernel module, which, say, changes the value of 
> the variable securelevel. 
> 
> So what's the situation? 
> 
> Anyway, from a security point of view I would like to completely
> disable loadable kernel modules. Is there a way to do it?

You cannot load or unload LKMs at securelevels greater than 0.
This is the case with -current as of Nov 29th 1995, and -stable
as of May 31st 1996.

Alex