Date: Mon, 15 Jun 1998 11:14:37 -0400 (EDT) From: woods@zeus.leitch.com (Greg A. Woods) To: freebsd-security@FreeBSD.ORG Subject: Re: bsd securelevel patch question Message-ID: <199806151514.LAA04480@brain.zeus.leitch.com> In-Reply-To: Niall Smart's message of "Sun, June 14, 1998 22:19:29 %2B0100" regarding "Re: bsd securelevel patch question" id <E0ylKBV-0001IS-00@oak71.doc.ic.ac.uk> References: <E0ylKBV-0001IS-00@oak71.doc.ic.ac.uk>
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[ On Sun, June 14, 1998 at 22:19:29 (+0100), Niall Smart wrote: ] > Subject: Re: bsd securelevel patch question > > This is not correct, the fix does not require the prevention of killing > immutable processes. Its effectiveness relies on the ability to detect > when a system daemon has died, and one other requirement noted below. > There are a number of ways to achieve the first: > > - Kernel modifications which log whenever a process which has no > controlling terminal dies. This is straightforward to achieve and > covers all the important cases. It is even useful for non-security > related reasons. Of course you can extend this patch to log whenever > any particular pid dies. This is the recommended approach. I presume you really mean "when a process which has no controlling terminal dies *abnormally*". Lots and lots of processes in the general category of "have no controlling terminal" will die "normally" during the lifetime of a system, and I don't think they need to be logged specially.... > - Never reuse PID's generated while the system was in secure level 0. > Again, this is relatively easy to achieve, and prevents the replacement > of daemons with trojans that have an identical pid, and the monitoring > can be performed in userland. There is still the question of who > monitors the death of the monitoring process. This is why the first > idea is superior. I don't think this is an either/or proposition -- they are not conflicting. I.e. "and", not "or" is the correct conjunction! -- Greg A. Woods +1 416 443-1734 VE3TCP <gwoods@acm.org> <robohack!woods> Planix, Inc. <woods@planix.com>; Secrets of the Weird <woods@weird.com> To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe security" in the body of the message
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