Re: [kernel-hardening] Re: [PATCH v5 next 5/5] net: modules: use request_module_cap() to load 'netdev-%s' modules

From: Kees Cook
Date: Tue Nov 28 2017 - 15:08:20 EST


On Tue, Nov 28, 2017 at 11:32 AM, Theodore Ts'o <tytso@xxxxxxx> wrote:
> On Tue, Nov 28, 2017 at 01:16:59PM +0100, Geo Kozey wrote:
>>
>> Userspace can be configured in a way which is compatible with those
>> changes being on the same as it can be configured to work with
>> selinux. That means on distro level or sysadmin level it's a
>> valuable tool. It's better than nothing and it's better than using
>> some out-of-tree patches instead. Switching one sysctl would make
>> their life easier.
>
> If *selinux* can opt-in to something more stringent, such that when
> you upgrade to a new version of selinux which enables something which
> breaks all modules unless you set up the rules corretly, I don't see a
> problem with it. It might force distributions not to go to the latest
> version of SELinux because users get cranky when their systems get
> broken, but for people like me, who *still* don't use SELinux because
> every few years, i try to enable on my development laptop running
> Debian, watch ***far*** too much stuff break. and then turn it off
> again. So tieing it to SELinux (as far as I am concerned) reduces it to
> a previously unsolved problem. :-)
>
> But that's different from opting it on by default for non-SELinux
> users. To which I can only say, "Please, No."

I don't want to see this tied to SELinux because it narrows the
audience, and SELinux still hasn't solved their issues in containers.
I think the per-task setting is sufficient.

Linus, are you okay with this series if the global sysctl gets dropped?

-Kees

--
Kees Cook
Pixel Security