Re: [RFC v2 00/10] Landlock LSM: Unprivileged sandboxing (cgroup delegation)

From: MickaÃl SalaÃn
Date: Sat Aug 27 2016 - 11:22:49 EST


Cc Tejun and the cgroups ML.

On 27/08/2016 17:10, MickaÃl SalaÃn wrote:
> On 27/08/2016 09:40, Andy Lutomirski wrote:
>> On Thu, Aug 25, 2016 at 3:32 AM, MickaÃl SalaÃn <mic@xxxxxxxxxxx> wrote:
>>>
>>> # Sandbox example with conditional access control depending on cgroup
>>>
>>> $ mkdir /sys/fs/cgroup/sandboxed
>>> $ ls /home
>>> user1
>>> $ LANDLOCK_CGROUPS='/sys/fs/cgroup/sandboxed' \
>>> LANDLOCK_ALLOWED='/bin:/lib:/usr:/tmp:/proc/self/fd/0' \
>>> ./sandbox /bin/sh -i
>>> $ ls /home
>>> user1
>>> $ echo $$ > /sys/fs/cgroup/sandboxed/cgroup.procs
>>> $ ls /home
>>> ls: cannot open directory '/home': Permission denied
>>>
>>
>> Something occurs to me that isn't strictly relevant to landlock but
>> may be relevant to unprivileged cgroups: can you cause trouble by
>> setting up a nastily-configured cgroup and running a setuid program in
>> it?
>>
>
> I hope notâ But the use of cgroups should not be mandatory for Landlock.
>

In a previous email:

On 26/08/2016 17:50, Tejun Heo wrote:
> I haven't looked in detail but in general I'm not too excited about
> layering security mechanism on top of cgroup. Maybe it makes some
> sense when security domain coincides with resource domains but at any
> rate please keep me in the loop.


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