CVE Request Qemu: scsi: esp: OOB write when using non-DMA mode in get_cmd

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

  Hello,

Quick Emulator(Qemu) built with the ESP/NCR53C9x controller emulation support 
is vulnerable to an OOB write access issue. The controller uses 16-byte FIFO 
buffer for command and information transfer. The OOB write occurs while 
reading from information transfer buffer via non-DMA mode in routine 
get_cmd().

A privileged user inside guest could use this flaw to crash the Qemu process 
resulting in DoS.

Upstream patch:
---------------
  -> https://lists.gnu.org/archive/html/qemu-devel/2016-06/msg00150.html

Reference:
----------
  -> https://bugzilla.redhat.com/show_bug.cgi?id=1341931

This issue was discovered by Li Qiang of 360.cn Inc.

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