CVE-2017-7980 Qemu: display: cirrus: OOB r/w access issues in bitblt routines

[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 r/w access issues. It could occur while copying 
VGA data via various bitblt functions.

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

Upstream patches:
-----------------
  -> http://git.qemu.org/?p=qemu.git;a=commitdiff;h=026aeffcb4752054830ba203020ed6eb05bcaba8
  -> http://git.qemu.org/?p=qemu.git;a=commitdiff;h=ffaf857778286ca54e3804432a2369a279e73aa7

Reference:
----------
  -> https://bugzilla.redhat.com/show_bug.cgi?id=1444371


This issue was independently reported by Jiangxin of PSIRT Huawei Inc. and Li 
Qiang of 360.cn Inc.

CVE-2017-7980 assigned via -> http://cveform.mitre.org/

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