Re: [PATCH 0/2] exec: Use sane stack rlimit for setuid exec

From: Kees Cook
Date: Fri Jul 07 2017 - 18:11:09 EST


On Fri, Jul 7, 2017 at 1:09 PM, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> On Fri, Jul 7, 2017 at 1:04 PM, Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> It looks like Kees went through the security modules [..]
>
> i take that back. It looks like Kees looked at smack, but not at
> SElinux, for example.

Well, I looked at the all but misthought about SELinux.

> selinux_bprm_secureexec() seems to just look at current_security(),
> not at the new stuff in bprm at all.

I was looking for cred. Yeah, I'll see what should happen here...

> Which would seem to be exactly the wrong thing to do, and is insane
> (why pass in bprm at all?) but comes from the fact that we used to
> call bprm_secureexec() in an insane place.
>
> So I think this patch series is sadly broken - I think it does the
> right thing, but the security modules definitely look like they need
> to be updated for that right thing.

Yeah, I'll rev this once SELinux is more clear...

-Kees

--
Kees Cook
Pixel Security