(RHSA-2015:1044) Important: virtio-win security and bug fix update

The virtio-win package provides paravirtualized network drivers for most
Microsoft Windows operating systems. Paravirtualized drivers are
virtualization-aware drivers used by fully virtualized guests running on
Red Hat Enterprise Linux. Fully virtualized guests using the
paravirtualized drivers gain significantly better I/O performance than
fully virtualized guests running without the drivers.

It was found that the Windows Virtio NIC driver did not sufficiently
sanitize the length of the incoming IP packets, as demonstrated by a packet
with IP options present but the overall packet length not being adjusted to
reflect the length of those options. A remote attacker able to send a
specially crafted IP packet to the guest could use this flaw to crash that
guest. (CVE-2015-3215)

Red Hat would like to thank Google Project Zero for reporting this issue.

This update also fixes the following bugs:

• When creating a Windows guest using virtio drivers and direct Logical
  Unit Number (LUN) access with more than 4 SCSI disks under one
  virtio-scsi-pci controller, the guest terminated unexpectedly with a stop
  error, also known as the blue screen of death. This update increases the
  maximum amount of LUNs per a single virtio-scsi-pci controller has been
  increased to 254, which prevents the described crash from occurring.
  (BZ#1207546)

• The license.txt file in the virtio-win build has been updated to include
  the correct year number in the copyright information section. (BZ#1183427)

All virtio-win users are advised to upgrade to this updated package, which
contains backported patches to correct these issues.