On Thu, Oct 29, 2009 at 10:34 AM, Dustin Kirkland <kirkland@xxxxxxxxxxxxx> wrote: > whitelist host virtio networking features > > This patch is a followup to 8eca6b1bc770982595db2f7207c65051572436cb, > fixing crashes when guests with 2.6.25 virtio drivers have saturated > virtio network connections. > > https://bugs.edge.launchpad.net/ubuntu/+source/qemu-kvm/+bug/458521 > > That patch should have been whitelisting *_HOST_* rather than the the > *_GUEST_* features. > > I tested this by running an Ubuntu 8.04 Hardy guest (2.6.24 kernel + > 2.6.25-virtio driver). I saturated both the incoming, and outgoing > network connection with nc, seeing sustained 6MB/s up and 6MB/s down > bitrates for ~20 minutes. Previously, this crashed immediately. Now, > the guest does not crash and maintains network connectivity throughout > the test. <snip> FYI... Canonical's Ubuntu Security Team will be filing a CVE on this issue, since there is a bit of an attack vector here, and since qemu-kvm-0.11.0 is generally available as an official release (and now part of Ubuntu 9.10). Guests running linux <= 2.6.25 virtio-net (e.g Ubuntu 8.04 hardy) on top of qemu-kvm-0.11.0 can be remotely crashed by a non-privileged network user flooding an open port on the guest. The crash happens in a manner that abruptly terminates the guest's execution (ie, without shutting down cleanly). This may affect the guest filesystem's general happiness. :-Dustin -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
