Re: cve request: systemd-machined: information exposure for docker containers

[Daniel J Walsh <dwalsh () redhat com>]

On 07/28/2016 10:42 AM, Simon McVittie wrote:
> On Thu, 28 Jul 2016 at 08:34:35 -0400, Daniel J Walsh wrote:
> > Lennart is wrong when he states that this only effects "user"
> > containers, any container that registers with
> > machinectl, will have this information revealed to non privileged user
> > processes.
> *Which* unprivileged user processes?
>
> If the unprivileged user processes are not in a container, they can get a
> significant amount of the same information by reading the host's /proc.
>
> If the unprivileged user processes are in a container or other confinement
> that prevents them from looking at the host's /proc, then one of the other
> things that confinement can/should prevent is unfiltered access to the host
> system's D-Bus system bus, which is how machinectl talks to systemd-machined.
>
> Lennart also points out on the systemd bug that the
> methods in question can be access-controlled (at your
> own risk, the policy language is horrible) by modifying
> /etc/dbus-1/system.d/org.freedesktop.machine1.conf. They don't appear to
> be mediated by /usr/share/polkit-1/actions/org.freedesktop.machine1.policy
> too, but they could be; that would be an enhancement request for systemd
> upstream.
>
> I think the bottom line here is that if the author of a container integration
> tool chooses to publish information in a central registry (systemd-machined),
> then they shouldn't be surprised to find the central registry's security model
> getting applied to that information.
>
>     S
So we can add documentation to oci-register-machine that if you use it,
this information
will not be available to the system.  If you don't want this information
revealed you can
uninstall the package, but tools like journalctl -M will no longer work
for docker/runc containers.