Re: [PATCH v4 1/2] tiocsti-restrict : Add owner user namespace to tty_struct

[Matt Brown]

On 05/03/2017 03:45 PM, Greg KH wrote:
> On Wed, May 03, 2017 at 12:32:07PM -0700, Kees Cook wrote:
> > On Mon, Apr 24, 2017 at 6:57 AM, Serge E. Hallyn <serge@xxxxxxxxxx> wrote:
> > > Quoting Matt Brown (matt@xxxxxxxxx):
> > > > This patch adds struct user_namespace *owner_user_ns to the tty_struct.
> > > > Then it is set to current_user_ns() in the alloc_tty_struct function.
> > > >
> > > > This is done to facilitate capability checks against the original user
> > > > namespace that allocated the tty.
> > > >
> > > > E.g. ns_capable(tty->owner_user_ns,CAP_SYS_ADMIN)
> > > >
> > > > This combined with the use of user namespace's will allow hardening
> > > > protections to be built to mitigate container escapes that utilize TTY
> > > > ioctls such as TIOCSTI.
> > > >
> > > > See: https://bugzilla.redhat.com/show_bug.cgi?id=1411256
> > > >
> > > > Signed-off-by: Matt Brown <matt@xxxxxxxxx>
> > >
> > > Acked-by: Serge Hallyn <serge@xxxxxxxxxx>
> >
> > This Ack didn't end up in the v5, but I think it stands, yes?
> >
> > Greg, is the v5 okay to pull for you or would a v6 with Acks/Reviews
> > included be preferred?
>
> v6 would be great, and we are dropping patch 2 from the series, right?
> I was expecting this to be resent.  I'll start looking at new patches
> like this after 4.12-rc1 is out.

I will create a v6 with the Acks/Reviews. I'd like to keep patch 2 in
since that got acked by at least Serge. (Kees also? or just patch 1?)

> thanks,
>
> greg k-h