Prasad J Pandit, Red Hat Product Security Team, reports:
Qemu emulator built with the Virtual Network Device(virtio-net)
support is vulnerable to a DoS issue. It could occur while receiving
large packets over the tuntap/macvtap interfaces and when guest's
virtio-net driver did not support big/mergeable receive buffers.
An attacker on the local network could use this flaw to disable
guest's networking by sending a large number of jumbo frames to the
guest, exhausting all receive buffers and thus leading to a DoS
situation.