Re: [PATCH] apparmor: allow to call vhost-user-gpu

On 2/14/20 1:14 PM, Christian Ehrhardt wrote: > > > On Fri, Feb 14, 2020 at 6:00 PM Jim Fehlig <jfehlig(a)suse.com > <mailto:jfehlig@suse.com>> wrote: > > On 2/13/20 4:32 AM, Christian Ehrhardt wrote: > > Configuring vhost-user-gpu like: > > <video> > > <driver name='vhostuser'/> > > <model type='virtio' heads='1'/> > > </video> > > Triggers an apparmor denial like: > > apparmor="DENIED" operation="exec" profile="libvirtd" > > name="/usr/lib/qemu/vhost-user-gpu" pid=888257 comm="libvirtd" > > requested_mask="x" denied_mask="x" fsuid=0 ouid=0 > > > > This helper is provided by qemu for vhost-user-gpu and thereby being > > in the same path as qemu_bridge_helper. Due to that adding a rule allowing > > to call uses the same path list. > > Does the vhost-usr-gpu helper need a profile to restrict its access, similar to > the bridge helper? > > Hi Jim, > Yes - we can later on add one, as soon as someone did the work to trace all the > things that will be needed. > I had no full setup - and I'm not sure about the multitude of potential > configurations - so I didn't go that far. > I didn't have that yet, but if anyone has please just add a follow on patch. > > The P in PUx allows that someone defines an external profile to guard it - and > it would be used, but without one existing the U allows it to fall back to > unconfined. Nod. That's reasonable behavior in the absence of an internal profile. > If/Once we add an internal profile like we do for bridge helper P can be changed > to C, but as I said I have no useful profile and no full setup to test&train one > at the moment. With a bit of searching I could probably find a setup, but getting access is another thing. In the meantime your patch is a fine alternative IMO Reviewed-by: Jim Fehlig <jfehlig(a)suse.com&gt;

Regards, Jim > > > > Signed-off-by: Christian Ehrhardt < christian.ehrhardt(a)canonical.com > <mailto:christian.ehrhardt@canonical.com>> > > --- > > src/security/apparmor/usr.sbin.libvirtd.in > <http://usr.sbin.libvirtd.in> | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/src/security/apparmor/usr.sbin.libvirtd.in > <http://usr.sbin.libvirtd.in> b/src/security/apparmor/ usr.sbin.libvirtd.in > <http://usr.sbin.libvirtd.in> > > index b384b7213b..1e137039e9 100644 > > --- a/src/security/apparmor/usr.sbin.libvirtd.in > <http://usr.sbin.libvirtd.in> > > +++ b/src/security/apparmor/usr.sbin.libvirtd.in > <http://usr.sbin.libvirtd.in> > > @@ -86,6 +86,7 @@ profile libvirtd @sbindir@/libvirtd > flags=(attach_disconnected) { > > /usr/{lib,lib64}/xen-common/bin/xen-toolstack PUx, > > /usr/{lib,lib64}/xen/bin/* Ux, > > /usr/lib/xen-*/bin/libxl-save-helper PUx, > > + /usr/{lib,lib64,lib/qemu,libexec}/vhost-user-gpu PUx, > > > > # Required by nwfilter_ebiptables_driver.c:ebiptablesWriteToTempFile() to > > # read and run an ebtables script. > > > > > > -- > Christian Ehrhardt > Staff Engineer, Ubuntu Server > Canonical Ltd