Re: [Qemu-devel] [PATCH] seccomp: adding a second whitelist

[Corey Bryant]

On 09/03/2013 02:21 PM, Paul Moore wrote:
> On Tuesday, September 03, 2013 02:08:28 PM Corey Bryant wrote:
> > On 09/03/2013 02:02 PM, Corey Bryant wrote:
> > > On 08/30/2013 10:21 AM, Eduardo Otubo wrote:
> > > > On 08/29/2013 05:34 AM, Stefan Hajnoczi wrote:
> > > > > On Wed, Aug 28, 2013 at 10:04:32PM -0300, Eduardo Otubo wrote:
> > > > > > Now there's a second whitelist, right before the vcpu starts. The
> > > > > > second
> > > > > > whitelist is the same as the first one, except for exec() and select().
> > > > >
> > > > > -netdev tap,downscript=/path/to/script requires exec() in the QEMU
> > > > > shutdown code path.  Will this work with seccomp?
> > > >
> > > > I actually don't know, but I'll test that as well. Can you run a test
> > > > with this patch and -netdev? I mean, if you're pointing that out you
> > > > might have a scenario already setup, right?
> > > >
> > > > Thanks!
> > >
> > > This uses exec() in net/tap.c.
> > >
> > > I think if we're going to introduce a sandbox environment that restricts
> > > existing QEMU behavior, then we have to introduce a new argument to the
> > > -sandbox option.  So for example, "-sandbox on" would continue to use
> > > the whitelist that allows everything in QEMU to work (or at least it
> > > should :).  And something like "-sandbox on,strict=on" would use the
> > > whitelist + blacklist.
> > >
> > > If this is acceptable though, then I wonder how we could go about adding
> > > new syscalls to the blacklist in future QEMU releases without regressing
> > > "-sandbox on,strict=on".
> >
> > Maybe a better approach is to provide support that allows libvirt to
> > define the blacklist and pass it to QEMU?
>
> FYI: I didn't want to mention this until I had some patches ready to post, but
> I'm currently working on adding syscall filtering, via libseccomp, to libvirt.
> I hope to get an initial RFC-quality patch out "soon".

Great, looking forward to seeing them.

--
Regards,
Corey Bryant