Re: [PATCH 3/5] v2 seccomp_filters: Enable ftrace-based system call filtering

Eric Paris
2011-05-26T19:09:10Z

On Thu, May 26, 2011 at 3:05 PM, <david@lang.hm> wrote:
> On Thu, 26 May 2011, Ingo Molnar wrote:
>
>> * Linus Torvalds <torvalds@linux-foundation.org> wrote:
>>
>>> It also gets rid of all configuration - one of the things that
>>> makes most security frameworks (look at selinux, but also just
>>> ACL's etc) such a crazy rats nest is the whole "set up for other
>>> processes". If it's designed very much to be about just the "self"
>>> process (after initialization etc), then I think that avoids pretty
>>> much all the serious issues.
>>
>> That's how the event filters work currently: even when inherited they
>> get removed when exec-ing a setuid task, so they cannot leak into
>> privileged context and cannot modify execution there.
>>
>> Inheritance works when requested, covering only same-credential child
>> tasks, not privileged successors.
>
> this is a very reasonable default, but there should be some way of saying
> that you want the restrictions to carry over to the suid task (I really know
> what I'm doing switch)

You mean the "i'm a hacker and want to be able to learn about tasks I
shouldn't be able to learn about" switch? No. You either get out of
the way on SUID or refuse to launch SUID apps. Those are the only
reasonable choices.