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

[Kees Cook]

On Wed, May 3, 2017 at 1:02 PM, Matt Brown <matt@xxxxxxxxx> wrote:
> 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?)

Sorry, I meant that patch 2's ack from serge got dropped accidentally.
i.e. he Acked v4, but it wasn't in v5.

Serge, just to double-check, does your Ack stand?

-Kees

-- 
Kees Cook
Pixel Security