CVE Request Qemu: scsi: esp: OOB r/w access while processing ESP_FIFO

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

  Hello,

Quick Emulator(Qemu) built with the ESP/NCR53C9x controller emulation support 
is vulnerable to an OOB r/w access issue. The controller uses 16-byte FIFO 
buffer the information transfer. The OOB r/w occurs while reading/writing to 
this buffer in esp_reg_read() and esp_reg_write() routines.

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

Upstream patch:
---------------
  -> https://lists.gnu.org/archive/html/qemu-devel/2016-06/msg01507.html

Reference:
----------
  -> https://bugzilla.redhat.com/show_bug.cgi?id=1343323

This issue was independently discovered and reported by Li Qiang of 360.cn Inc 
and Security Team at Huawei Inc.


Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
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