Re: [PATCH v3 2/2] modules:capabilities: add a per-task modules autoload restriction
From: Djalal Harouni <hidden>
Date: 2017-04-22 01:19:59
Also in:
linux-security-module, lkml
On Sat, Apr 22, 2017 at 2:12 AM, Djalal Harouni [off-list ref] wrote:
On Sat, Apr 22, 2017 at 1:51 AM, Andy Lutomirski [off-list ref] wrote: [...]quoted
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I personally like my implicit_rights idea, and it might be interesting to prototype it.I don't like blocking a needed feature behind a large super-feature that doesn't exist yet. We'd be able to refactor this code into using such a thing in the future, so I'd prefer to move ahead with this since it would stop actual exploits.I don't think the super-feature is so hard, and I think we should not add the per-task thing the way it's done in this patch. Let's not add per-task things where the best argument for their security is "not sure how it would be exploited".Actually the XFRM framework CVE-2017-7184 [1] is one real example, of course there are others. The exploit was used on a generic distro during a security contest that distro is Ubuntu. That distro will never provide a module autoloading restriction by default to not harm it's users. Consumers or containers/sandboxes then can run their confined apps using such facilities. These bugs will stay in embedded devices that use these generic distros for ever.
The DCCP CVE-2017-6074 exploit: http://seclists.org/oss-sec/2017/q1/503 Well, pretty sure there is more... the bugs are real, as their exploits. Anyway I think these features can coexist as they are optional, and most process trees protections can get along by design. -- tixxdz