CVE-2017-2620 Qemu: display: cirrus: out-of-bounds access issue while in cirrus_bitblt_cputovideo

[P J P <ppandit () redhat com>]

  Hello,

Quick emulator(Qemu) built with the Cirrus CLGD 54xx VGA Emulator support is 
vulnerable to an out-of-bounds access issue. It could occur while copying VGA 
data in cirrus_bitblt_cputovideo.

A privileged user inside guest could use this flaw to crash the Qemu process 
resulting in DoS OR potentially execute arbitrary code on the host with 
privileges of Qemu process on the host.

Reference:
----------
  -> https://bugzilla.redhat.com/show_bug.cgi?id=1420460

* 'CVE-2017-2620' has been assigned to this issue by Red Hat Inc.
* Attached herein is a proposed patch to fix this issue.

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F

Attachment: cirrus-add-blit-is-unsafe-to-cirrus-bitblt-cputovideo.patch
Description: