On 15/05/14, Eric W. Biederman wrote: > Paul Moore <pmoore@xxxxxxxxxx> writes: > > As Eric, and others, have stated, the container concept is a userspace idea, > > not a kernel idea; the kernel only knows, and cares about, namespaces. This > > is unlikely to change. > > > > However, as Steve points out, there is precedence for the kernel to record > > userspace tokens for the sake of audit. Personally I'm not a big fan of this > > in general, but I do recognize that it does satisfy a legitimate need. Think > > of things like auid and the sessionid as necessary evils; audit is already > > chock full of evilness I doubt one more will doom us all to hell. > > > > Moving forward, I'd like to see the following: > > > * Create a container ID token (unsigned 32-bit integer?), similar to > > auid/sessionid, that is set by userspace and carried by the kernel to be used > > in audit records. I'd like to see some discussion on how we manage this, e.g. > > how do handle container ID inheritance, how do we handle nested containers > > (setting the containerid when it is already set), do we care if multiple > > different containers share the same namespace config, etc.? > > > > Can we all live with this? If not, please suggest some alternate ideas; > > simply shouting "IT'S ALL CRAP!" isn't helpful for anyone ... it may be true, > > but it doesn't help us solve the problem ;) > > Without stopping and defining what someone means by container I think it > is pretty much nonsense. Not complete, but this is why I'm asking for a standards document... > Should every vsftp connection get a container every? Every chrome tab? > > At some of the connections per second numbers I have seen we might > exhaust a 32bit number in an hour or two. Will any of that make sense > to someone reading the audit logs? So making it 64bits buys us some time, but sure... I think your definition of a container may be a bit more liberal than what we're trying to understand... > Without considerning that container creation is an unprivileged > operation I think it is pretty much nonsense. Do I get to say I am any > container I want? That would seem to invalidate the concept of > userspace setting a container id. Ok, my impression was that we're dealing with a privileged application as I alluded with the need to create a new CAP_AUDIT_CONTAINER_ID or something... > How does any of this interact with setns? AKA entering a container? You mean entering another namespace that might all be part of one container? Or an an application attempting to enter the namespace of another container? > I will go as far as looking at patches. If someone comes up with > a mission statement about what they are actually trying to achieve and a > mechanism that actually achieves that, and that allows for containers to > nest we can talk about doing something like that. I don't pretend these patches are anywhere near finished or ready for upstream. > But for right now I just hear proposals for things that make no sense > and can not possibly work. Not least because it will require modifying > every program that creates a container and who knows how many of them > there are. Especially since you don't need to be root. Modifying > /usr/bin/unshare seems a little far out to me. My understanding is that just spawning or changing namespace doesn't imply spawning or changing containers. I also don't necessarily assume that creating a container is an atomic operation, though that concept might make some sense to understand or predict the boundaries of actions... > Eric - RGB -- Richard Guy Briggs <rbriggs@xxxxxxxxxx> Senior Software Engineer, Kernel Security, AMER ENG Base Operating Systems, Red Hat Remote, Ottawa, Canada Voice: +1.647.777.2635, Internal: (81) 32635, Alt: +1.613.693.0684x3545 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
