Re: [RFC] Introduce CAP_CHECKPOINT capability and filter map_files/access

From: Andrew Morton
Date: Thu Nov 17 2011 - 15:54:16 EST


On Thu, 17 Nov 2011 09:41:05 -0600
"Serge E. Hallyn" <serge.hallyn@xxxxxxxxxxxxx> wrote:

> > - (not yet merged) clone-with-specified-pid, might be changed to last_pid+clone setup
> > - (not yet published/stabilized) prctls calls to tune up vDSO and elements
> > of mm_struct such as mm->start_code, mm->end_code, mm->start_data and etc
> >
> > I would like to gather people opinions on such approach as a general.
> > _ANY_ comments are highly appreciated. Would it worth it or not (since
> > CAPs space is pretty limited one).
>
> It's hard to have a specific dialogue without the full c/r patchset and
> idea of the architecture of the exploiters (ie c/r and maybe
> debuggers)
>
> Sorry, the security implications of the in-kernel c/r syscalls were
> pretty simple and clear to me, but those of the new approach are not.

yup.

>From a development-order perspective perhaps it is better to get
everything working and stabilized for root first. Then as a separate
activity start working on making it available to less-privileged users.

We would need to be confident that such a second development effort
doesn't cause back-compatibility issues (ie: interface changes) for
existing root users.



Is it possible that once everything is working for root, we realise
that we can get it all working for non-root users via suitable setuid
userspace tools?
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