Bug 1172765 (CVE-2014-8134) - CVE-2014-8134 kernel: x86: espfix not working for 32-bit KVM paravirt guests
Summary: CVE-2014-8134 kernel: x86: espfix not working for 32-bit KVM paravirt guests
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2014-8134
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:
Depends On: 1172767 1172769
Blocks: 1170693
TreeView+ depends on / blocked
 
Reported: 2014-12-10 17:12 UTC by Petr Matousek
Modified: 2023-05-12 06:48 UTC (History)
30 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
It was found that the espfix functionality does not work for 32-bit KVM paravirtualized guests. A local, unprivileged guest user could potentially use this flaw to leak kernel stack addresses.
Clone Of:
Environment:
Last Closed: 2016-05-11 07:27:18 UTC
Embargoed:

Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2016:0855 0 normal SHIPPED_LIVE Moderate: kernel security, bug fix, and enhancement update 2016-05-10 22:43:57 UTC

Description Petr Matousek 2014-12-10 17:12:41 UTC 
It was found that espfix funcionality (when returning to userspace with a 16
bit stack, the CPU will not restore the high word of esp for us on executing
iret and thus potentially leaks kernel addresses; espfix fixes this) does not
work for 32-bit KVM paravirt guests.

A local unprivileged user could potentially use this flaw to leak kernel
stack addresses.

Proposed upstream patch:
http://www.spinics.net/lists/kvm/msg111458.html

Acknowledgements:

Red Hat would like to thank Andy Lutomirski for reporting this issue.
Comment 1 Petr Matousek 2014-12-10 17:13:17 UTC 
Statement:

This issue did not affect the Linux kernel packages as shipped with Red
Hat Enterprise Linux 5 and 7, and Red Hat Enterprise Linux MRG 2.
Comment 3 Petr Matousek 2014-12-10 17:14:47 UTC 
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1172769]
Comment 4 Petr Matousek 2014-12-15 18:28:08 UTC 
Upstream patch:

https://git.kernel.org/cgit/virt/kvm/kvm.git/commit/?h=linux-next&id=29fa6825463c97e5157284db80107d1bfac5d77b
Comment 5 Fedora Update System 2014-12-21 06:36:34 UTC 
kernel-3.17.7-200.fc20 has been pushed to the Fedora 20 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 6 Fedora Update System 2014-12-22 02:32:43 UTC 
kernel-3.17.7-300.fc21 has been pushed to the Fedora 21 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 7 Fedora Update System 2015-01-05 07:34:46 UTC 
kernel-3.14.27-100.fc19 has been pushed to the Fedora 19 stable repository.  If problems still persist, please make note of it in this bug report.
Comment 8 errata-xmlrpc 2016-05-10 22:06:11 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2016:0855 https://rhn.redhat.com/errata/RHSA-2016-0855.html
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