Vigil@nce - QEMU-KVM: denial of service via virtio-net
April 2010 by Vigil@nce
This bulletin was written by Vigil@nce : http://vigilance.fr/
SYNTHESIS OF THE VULNERABILITY
An attacker can send several data to a QEMU-KVM guest system,
using virtio-net, in order to stop it.
Severity: 2/4
Creation date: 29/03/2010
DESCRIPTION OF THE VULNERABILITY
QEMU-KVM uses the KVM kernel module, and can use VIRTIO to
communicate efficiently with the kernel.
The TSO (TCP Segmentation Offload) feature is used to delegate the
segmentation of TCP data to the network device.
The virtio_net_bad_features() of QEMU-KVM does not forbid the
virtualization of TSO. However, this feature is not correctly
implemented, and its usage stops the QEMU-KVM guest system.
An attacker can therefore send several data to a QEMU-KVM guest
system, using virtio-net, in order to stop it.
ACCESS TO THE COMPLETE VIGIL@NCE BULLETIN
http://vigilance.fr/vulnerability/QEMU-KVM-denial-of-service-via-virtio-net-9542