[Secure-testing-team] Bug#809229: CVE-2015-8550: xen: unsafe access to shared memory

[Michael Tokarev]

Source: qemu
Version: 2.1+dfsg-1
Severity: important
Tags: security patch upstream fixed-upstream pending

CVE-2015-8550 (XSA-155).  xenfb and xen/blkif reads shared memory contents
more than once which open possibility to verification bypass from guest.
http://xenbits.xen.org/xsa/advisory-155.html

The issue has been fixed past upstream 2.5.0 release.

Filing this bug against qemu version 2.1 (jessie), because in Debian, only
in jessie xen uses qemu.  Before jessie, xen used its own copy of qemu.