Re: [Xen-devel] [PATCH] xenstored: allow guests to reintroduce themselves

[Vincent Hanquez <vincent.hanquez@xxxxxxxxxxxxx>]

On 08/09/2011 11:14 AM, Keir Fraser wrote:
> On 09/08/2011 11:08, "Vincent Hanquez"<vincent.hanquez@xxxxxxxxxxxxx>
> wrote:
>
> > > xenstored: allow guests to reintroduce themselves
> > >
> > > During kexec all old watches have to be removed, otherwise the new
> > > kernel will receive unexpected events. Allow a guest to introduce itself
> > > and cleanup all of its watches.
> > What about security wise ?
> >
> > Guest userspace suddenly becomes able to do this operation (and DoS themself)
> > where they used to be limited to normal read/write/.. operations.
> Guest userspace can already DoS the guest if it has access to xenstore, by
> messing with xenbus I/O connections, for example.
How so ?
It seems we validate userspace packets (at least on linux) before actually 
putting them on the ring.

--
Vincent

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel