Bug 1283934 (CVE-2016-1922) - CVE-2016-1922 Qemu: i386: null pointer dereference in vapic_write()
Summary: CVE-2016-1922 Qemu: i386: null pointer dereference in vapic_write()
Status: CLOSED WONTFIX
Alias: CVE-2016-1922
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard: impact=low,public=20151218,reported=2...
Keywords: Security
Depends On: 1292766 1292767
Blocks: 1283937
TreeView+ depends on / blocked
 
Reported: 2015-11-20 10:29 UTC by Adam Mariš
Modified: 2019-06-11 11:13 UTC (History)
25 users (show)

(edit)
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).
Clone Of:
(edit)
Last Closed: 2019-06-08 02:45:43 UTC


Attachments (Terms of Use)

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 2 Adam Mariš 2015-11-20 10:40:36 UTC
Acknowledgments:

Red Hat would like to thank Ling Liu of Qihoo 360 Inc. for reporting this issue.

Comment 3 Prasad J Pandit 2015-12-18 10:02:33 UTC
Created xen tracking bugs for this issue:

Affects: fedora-all [bug 1292767]

Comment 4 Prasad J Pandit 2015-12-18 10:02:46 UTC
Created qemu tracking bugs for this issue:

Affects: fedora-all [bug 1292766]

Comment 5 Prasad J 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.


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