Subject: Re: [PATCH] [request for inclusion] Realtime LSM
From: Lee Revell <rlrevell@joe-job.com>
To: Matt Mackall <mpm@selenic.com>
Cc: Chris Wright <chrisw@osdl.org>, "Jack O'Quin" <joq@io.com>,
       Christoph Hellwig <hch@infradead.org>, Andrew Morton <akpm@osdl.org>,
       paul@linuxaudiosystems.com, arjanv@redhat.com, mingo@elte.hu,
       alan@lxorguk.ukuu.org.uk, linux-kernel@vger.kernel.org
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Date: Tue, 11 Jan 2005 16:38:14 -0500
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On Tue, 2005-01-11 at 13:28 -0800, Matt Mackall wrote:
> But I'm also still not convinced this policy can't be most flexibly
> handled by a setuid helper together with the mlock rlimit.
> 

Quoting my message from a few days ago:

On Thu, 2005-01-06 at 17:18 -0800, Matt Mackall wrote:
> Why can't this be done with a simple SUID helper to promote given
> tasks to RT with sched_setschedule, doing essentially all the checks
> this LSM is doing? 
> 
> Objections of "because it requires dangerous root or suid" don't fly,
> an RT app under user control can DoS the box trivially. Never mind you
> need root to configure the LSM anyway..

Yes but a bug in an app running as root can trash the filesystem.  The
worst you can do with RT privileges is lock up the machine.

Lee

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