Bug 1283934 (CVE-2016-1922)

Summary:	CVE-2016-1922 Qemu: i386: null pointer dereference in vapic_write()
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	abaron, apevec, areis, ayoung, carnil, chrisw, dallan, gkotton, jen, jschluet, knoel, lhh, lpeer, markmc, mkenneth, mrezanin, mst, osoukup, pbonzini, ppandit, rbryant, sclewis, security-response-team, slong, srevivo, tdecacqu
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	A NULL-pointer dereference flaw was found in the QEMU emulator built with TPR optimization for 32-bit Windows guests support. The flaw occurs when doing I/O-port write operations from the HMP interface. The 'current_cpu' value remains null because it is not called from the cpu_exec() loop, and dereferencing it results in the flaw. An attacker with access to the HMP interface could use this flaw to crash the QEMU instance (denial of service).	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 02:45:43 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1292766, 1292767
Bug Blocks:	1283937

Description Adam Mariš 2015-11-20 10:29:50 UTC

Qemu emulator built with the TPR optimization for 32-bit Windows guests support is vulnerable to a null pointer dereference flaw. It occurs while doing I/O port write operations via hmp interface. In that, 'current_cpu' remains null, which leads to the null pointer dereference.

A user/process could use this flaw to crash the Qemu instance, resulting in DoS issue.

Upstream patch:
---------------
  -> https://lists.gnu.org/archive/html/qemu-devel/2016-01/msg02812.html

Reference:
----------
  -> http://www.openwall.com/lists/oss-security/2016/01/16/6

Comment 3 Prasad Pandit 2015-12-18 10:02:33 UTC

Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1292767]

Comment 4 Prasad Pandit 2015-12-18 10:02:46 UTC

Created qemu tracking bugs for this issue:

Affects: fedora-all [bug 1292766]

Comment 5 Prasad Pandit 2015-12-18 10:14:31 UTC

Statement: 

This issue does not affect the versions of the kvm and xen packages as shipped with Red Hat Enterprise Linux 5.

This issue does not affect the versions of the qemu-kvm packages as shipped with Red Hat Enterprise Linux 6, and the Red Hat Enterprise Linux 6 based versions of qemu-kvm-rhev packages as shipped with Red Hat Enterprise Virtualization 3.

This issue affects the versions of the qemu-kvm packages as shipped with Red Hat Enterprise Linux 7.

This issue affects the Red Hat Enterprise Linux 7 based versions of the qemu-kvm-rhev packages as shipped with Red Hat Enterprise Virtualization 3.

This has been rated as having Low security impact and is not currently
planned to be addressed in future updates. For additional information, refer
to the Red Hat Enterprise Linux Life Cycle:
https://access.redhat.com/support/policy/updates/errata/.

Comment 6 Fedora Update System 2016-01-24 03:26:33 UTC

qemu-2.4.1-6.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.

Comment 7 Fedora Update System 2016-02-02 00:52:25 UTC

qemu-2.3.1-11.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.

Comment 8 Fedora Update System 2016-03-19 21:22:19 UTC

xen-4.5.2-9.fc22 has been pushed to the Fedora 22 stable repository. If problems still persist, please make note of it in this bug report.

Comment 9 Fedora Update System 2016-03-20 02:26:09 UTC

xen-4.5.2-9.fc23 has been pushed to the Fedora 23 stable repository. If problems still persist, please make note of it in this bug report.