Re: [PATCH v3 2/2] modules:capabilities: add a per-task modules autoload restriction

[Djalal Harouni]

On Sat, Apr 22, 2017 at 2:12 AM, Djalal Harouni <tixxdz@xxxxxxxxx> wrote:
> On Sat, Apr 22, 2017 at 1:51 AM, Andy Lutomirski <luto@xxxxxxxxxx> wrote:
> [...]
>>>> 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