Re: [kernel-hardening] Re: [PATCH 1/2] security, perf: allow further restriction of perf_event_open

From: Mark Rutland
Date: Thu Aug 04 2016 - 13:10:07 EST


On Thu, Aug 04, 2016 at 12:32:32PM -0400, Daniel Micay wrote:
> On Thu, 2016-08-04 at 17:10 +0100, Mark Rutland wrote:
> I wasn't talking specifically about perf.

Then this is irrelevant to a discussion about limiting access to the
perf interface.

Hardening drivers in general is a very interesting topic, but it is a
different topic.

> > But please, let's frame the argument to match reality.
>
> The argument is framed in reality. Stating that it now often takes a
> few hours to find a vulnerability with the unaltered, widely known
> public perf fuzzer is not impressive. It's really an argument for
> claiming that it's a significant security issue.

My claim was not that the mainline code was impressively perfect, but
rather that the vendor code was worse, countering a prior claim
otherwise. Hence, reality.

There is cetainly much that can be done to improve things, if we discuss
that which is actually applicable.

Thanks,
Mark.