Re: [PATCH 1/2] virtio-net: Verify page list size before fittinginto skb

[Sasha Levin]

On Mon, 2011-09-26 at 22:45 +0300, Pekka Enberg wrote:
> On Mon, Sep 26, 2011 at 10:37 PM, Sasha Levin <levinsasha928@xxxxxxxxx> wrote:
> >> Interesting.  This is a theoretical issue, correct?
> >> Not a crash you actually see.
> >
> > Actually it was an actual crash caused when our virtio-net driver in kvm
> > tools did funny things and passed '(u32)-1' length as a buffer length to
> > the guest kernel.
> 
> I'm not sure what Michael means with "theoretical issue" here. Can the guest
> driver assume that the hypervisor doesn't attempt to do nasty things?

afaik if the hypervisor can access the vcpus and the memory of the
guest, this shouldn't be a security issue - more of a bug prevention
issue.

I guess it'll be interesting the other way around, when it's the guest
that passes this buggy information to the hypervisor.

-- 

Sasha.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/