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

[Corey Bryant]

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".

By the way, are any test buckets running regularly with -sandbox on?

--
Regards,
Corey Bryant

> > Stefan