Messages in this thread | | | Date | Sun, 10 Sep 2006 12:41:05 +0200 | From | David Madore <> | Subject | Re: patch to make Linux capabilities into something useful (v 0.3.1) |
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On Sat, Sep 09, 2006 at 11:40:38AM +0000, Pavel Machek wrote: > > > If you can find another uid to hijack, that other uid has bad > > > problems. And I do not think you'll commonly find another uid to > > > hijack. > > > > How about another gid, then? Should we reset all caps on sgid exec? > > Yes. Any setuid/setgid exec is a security barrier, and weird (or new) > semantics may not cross that barrier.
Right, so what I was saying was: if you reset all regular caps on sgid exec, anyone can trivially reset all regular caps by creating a sgid program (users are always members of a great many groups so "finding another gid to hijack" is trivial). So CAP_REG_SXID needs to be off all the time, so we lose again.
But I'll make this a securebit ("unsanitized sxid"), with the behavior you advertise as default (0).
> > Ultimately a compromise is to be reached between security and > > flexibility... The problem is, I don't know who should make the > > decision. > > Go for security here. (Normally, consensus on the list is needed for > merging the patch).
I am now completely convinced the patch will never be merged. :-( Linux will have useless caps forever...
-- David A. Madore (david.madore@ens.fr, http://www.madore.org/~david/ ) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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