Mailing List Archive

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Xen Security Advisory XSA-94

ARM hypervisor crash on guest interrupt controller access

ISSUE DESCRIPTION
=================

When handling a guest access to the virtual GIC distributor (interrupt
controller) Xen could dereference a pointer before checking it for
validity leading to a hypervisor crash and host Denial of Service.

IMPACT
======

A buggy or malicious guest can crash the host.

VULNERABLE SYSTEMS
==================

Both 32- and 64-bit ARM systems are vulnerable from Xen 4.4 onward.

x86 systems are not vulnerable.

MITIGATION
==========

None.

NOTE REGARDING LACK OF EMBARGO
==============================

This bug was publicly reported on xen-devel, before it was appreciated
that there was a security problem.

CREDITS
=======

The initial bug was discovered by Thomas Leonard and the security
aspect was diagnosed by Julien Grall.

RESOLUTION
==========

Applying the appropriate attached patch resolves this issue.

xsa94.patch xen-unstable, Xen 4.4.x

$ sha256sum xsa94*.patch
ad0f20577400756a1786daeafef86fa870727ec35b48f71f565e4a30dcbda58d xsa94.patch
$
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)

iQEcBAEBAgAGBQJTV7qTAAoJEIP+FMlX6CvZ08EH/3pIhD1lCXex3pbvo0BFIc2y
+XqJmLQ8QVeuk1Q9etEVbJxC8YvbmunefyCyfXIYQpL5jWqJdOAGzSktLOuaGrrM
ENG6kFyiC6pxLouJb+BAm3qOfe3vVCdkWh9ouWQGC/3FqbSM+2QGI0vUyxtfmmga
IDeQ+CjyWVVhmR7Tb76Gc/pMLnrfD1HTZSgTe8NacqbnZuXzPMrxkKw8BleK/boH
L5r/0Y/GqqOe5LRqCOZt8U7jlcfwAs+rqUI0UDz70YvokcBH7RwaRiolZxicLdjP
4lFJH8q9d45EA9JI+Xifv2QZ9tJMRNhRtTQpqIS8swAROOM/SblpPUPlOiPvyaE=
=RGUg
-----END PGP SIGNATURE-----