Re: [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs

[Thomas Graf <tgraf-G/eBtMaohhA@public.gmane.org>]

On 10/08/15 at 08:20pm, Hannes Frederic Sowa wrote:
> Hi Alexei,
> 
> On Thu, Oct 8, 2015, at 07:23, Alexei Starovoitov wrote:
> > The feature is controlled by sysctl kernel.unprivileged_bpf_disabled.
> > This toggle defaults to off (0), but can be set true (1).  Once true,
> > bpf programs and maps cannot be accessed from unprivileged process,
> > and the toggle cannot be set back to false.
> 
> This approach seems fine to me.
> 
> I am wondering if it makes sense to somehow allow ebpf access per
> namespace? I currently have no idea how that could work and on which
> namespace type to depend or going with a prctl or even cgroup maybe. The
> rationale behind this is, that maybe some namespaces like openstack
> router namespaces could make usage of advanced ebpf capabilities in the
> kernel, while other namespaces, especially where untrusted third parties
> are hosted, shouldn't have access to those facilities.
> 
> In that way, hosters would be able to e.g. deploy more efficient
> performance monitoring container (which should still need not to run as
> root) while the majority of the users has no access to that. Or think
> about routing instances in some namespaces, etc. etc.

The standard way of granting privileges like this for containers is
through CAP_ which does seem like a good fit for this as well and would
also solve your mentioned openstack use case.