Re: [PATCH V6 05/10] audit: log creation and deletion of namespace instances

From: Paul Moore
Date: Sat May 16 2015 - 08:17:06 EST


On Sat, May 16, 2015 at 5:46 AM, Daniel J Walsh <dwalsh@xxxxxxxxxx> wrote:
> On 05/15/2015 05:05 PM, Paul Moore wrote:
>> On Thursday, May 14, 2015 11:23:09 PM Andy Lutomirski wrote:
>>> On Thu, May 14, 2015 at 7:32 PM, Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
>>>> On 15/05/14, Paul Moore wrote:
>>>>> * Look at our existing audit records to determine which records should
>>>>> have
>>>>> namespace and container ID tokens added. We may only want to add the
>>>>> additional fields in the case where the namespace/container ID tokens are
>>>>> not the init namespace.
>>>> If we have a record that ties a set of namespace IDs with a container
>>>> ID, then I expect we only need to list the containerID along with auid
>>>> and sessionID.
>>> The problem here is that the kernel has no concept of a "container", and I
>>> don't think it makes any sense to add one just for audit. "Container" is a
>>> marketing term used by some userspace tools.
>>>
>>> I can imagine that both audit could benefit from a concept of a
>>> namespace *path* that understands nesting (e.g. root/2/5/1 or
>>> something along those lines). Mapping these to "containers" belongs
>>> in userspace, I think.
>> It might be helpful to climb up a few levels in this thread ...
>>
>> I think we all agree that containers are not a kernel construct. I further
>> believe that the kernel has no business generating container IDs, those should
>> come from userspace and will likely be different depending on how you define
>> "container". However, what is less clear to me at this point is how the
>> kernel should handle the setting, reporting, and general management of this
>> container ID token.
>>
> Wouldn't the easiest thing be to just treat add a containerid to the
> process context like auid.

I believe so. At least that was the point I was trying to get across
when I first jumped into this thread.

> Then make it a privileged operation to set it. Then tools that care about
> auditing like docker can set the ID
> and remove the Capability from it sub processes if it cares. All
> processes adopt parent processes containerid.
> Now containers can be audited and as long as userspace is written
> correctly nested containers can either override the containerid or not
> depending on what the audit rules are.

This part I'm still less certain on. I agree that setting the
container ID should be privileged in some sense, but the kernel
shouldn't *require* privilege to create a new container (however the
user chooses to define it). Simply requiring privilege to set the
container ID and failing silently may be sufficient.

--
paul moore
www.paul-moore.com
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