|
|
Log in / Subscribe / Register

Walsh: Cool things with SELinux... Introducing sandbox -X

Walsh: Cool things with SELinux... Introducing sandbox -X

Posted Sep 18, 2009 15:41 UTC (Fri) by nix (subscriber, #2304)
In reply to: Walsh: Cool things with SELinux... Introducing sandbox -X by rahulsundaram
Parent article: Walsh: Cool things with SELinux... Introducing sandbox -X

It may be the case that PaXTeam's native language is not English. It would be obvious to all native English speakers that 'be able to trust that the content can't cause the filter programs to do evil things' is not the same thing as 'be able to trust that the content can't cause the filter programs to do any evil things whatsoever, forever, regardless of kernel bugs, cosmic rays, and Doctor Impossible', but perhaps it isn't obvious to a non-native speaker.

(More precisely, SELinux is sandboxing the *applications* so that bugs in the *applications* do not cause privilege escalation. It can't sandbox the kernel itself, and never has been able to: the most it can do is 'accidentally' prevent the occasional escalation if, say, some escalation depends on doing something to some entity that SELinux is in any case denying access to. I don't see how anything short of VMs could sandbox the kernel itself, and even then you're vulnerable to kernel bugs in the VM, as PaXTeam et al have said ad nauseam.)

(Perhaps Dan *could* have said as much, but I agree, it is ridiculous to expect every single blog post to come with a long disclaimer lest anonymous trolls rip it to shreds after misreading it. Every security solution has a vast list of conditions it doesn't handle: the place to document that is in the docs for the security solution itself, not in every blog post that ever mentions said security solution.)

(I fully expect to get a bunch of virulently offensive followups to this from the pax and grsecurity trolls, as usual. I don't care, they're irredeemable. It's other people who matter.)


to post comments

Walsh: Cool things with SELinux... Introducing sandbox -X

Posted Sep 18, 2009 17:01 UTC (Fri) by dlang (guest, #313) [Link] (1 responses)

the problem is that the SELinux proponents keep claiming that if everyone just used SELinux there would be no possibility of security problems in linux. and further, because people refuse to use SELinux, all security exploits are then the result of this decision.

that may be overstating this slightly, but not by much.

usually I consider the posts by PaXTeam to be extreme in their claims, but in this case I think the point that is being made that SELinux does not defend against malware in content is absolutly correct.

Walsh: Cool things with SELinux... Introducing sandbox -X

Posted Sep 20, 2009 19:40 UTC (Sun) by nix (subscriber, #2304) [Link]

Oh, I certainly agree with *that*. A lot of SELinux proponents seriously
overegg the pudding. It'll protect only against *userspace* vulns
compromising the local system further: not necessarily against userspace
vulns compromising other systems and not against kernel vulns. Still
that's a fairly large proportion of vulns...


Copyright © 2026, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds