Bug 1172806 (CVE-2014-9322)

Summary: CVE-2014-9322 kernel: x86: local privesc due to bad_iret and paranoid entry incompatibility
Product: [Other] Security Response Reporter: Petr Matousek <pmatouse>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: agordeev, aquini, bhu, carnil, dhoward, esammons, fhrbata, iboverma, jkacur, jross, kernel-mgr, lgoncalv, lwang, matt, mcressma, mdshaikh, mguzik, mmilgram, nmurray, pholasek, plougher, rvrbovsk, security-response-team, skito, vgoyal, williams
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: impact=important,public=20141215,reported=20141202,source=vendor-sec,cvss2=7.2/AV:L/AC:L/Au:N/C:C/I:C/A:C,cvss3=8.4/CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H,cwe=CWE-841,rhel-4/kernel=affected,rhel-5/kernel=affected,rhel-5.6.z/kernel=affected,rhel-5.9.z/kernel=affected,rhel-6/kernel=affected,rhel-6.2.z/kernel=affected,rhel-6.4.z/kernel=affected,rhel-6.5.z/kernel=affected,rhel-7/kernel=affected,mrg-2/kernel=affected,fedora-all/kernel=notaffected
Fixed In Version: Doc Type: Bug Fix
Doc Text:
A flaw was found in the way the Linux kernel handled GS segment register base switching when recovering from a #SS (stack segment) fault on an erroneous return to user space. A local, unprivileged user could use this flaw to escalate their privileges on the system.
Story Points: ---
Clone Of: Environment:
Last Closed: 2015-01-06 20:20:16 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---
Bug Depends On: 1172809, 1172810, 1172811, 1172812, 1172813, 1172814, 1172945, 1173083, 1173084, 1173085, 1173591, 1173592, 1175501    
Bug Blocks: 1170693    

Description Petr Matousek 2014-12-10 19:31:55 UTC
It was found that because paranoid entry does not contain the swapgs fixup for
bad_iret (unlike error entry), under certain conditions (#SS on iret) it can
happen that bad_iret is reached with usergs instead of kernelgs that it is
expecting.

A local unprivileged user can use this flaw to increase their privileges on
the system.

Upstream fix:
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=6f442be2fb22be02cafa606f1769fa1e6f894441

Acknowledgements:

Red Hat would like to thank Andy Lutomirski for reporting this issue.

Comment 1 Petr Matousek 2014-12-10 19:32:23 UTC
Statement:

This issue does affect the Linux kernel packages as shipped with Red Hat
Enterprise Linux 4, 5, 6, and 7, and Red Hat Enterprise MRG 2. Future Linux
kernel updates for the respective releases will address this issue.

Comment 4 Petr Matousek 2014-12-10 19:36:03 UTC
Fedora included the patch for this issue as part of the CVE-2014-9090 fix and the impact was limited to local DoS due to the espfix64 functionality.

Comment 9 errata-xmlrpc 2014-12-16 18:52:05 UTC
This issue has been addressed in the following products:

  MRG for RHEL-6 v.2

Via RHSA-2014:1998 https://rhn.redhat.com/errata/RHSA-2014-1998.html

Comment 10 errata-xmlrpc 2014-12-16 19:14:38 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2014:1997 https://rhn.redhat.com/errata/RHSA-2014-1997.html

Comment 13 errata-xmlrpc 2014-12-17 18:28:32 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 5

Via RHSA-2014:2008 https://rhn.redhat.com/errata/RHSA-2014-2008.html

Comment 14 errata-xmlrpc 2014-12-17 18:39:00 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6.5 EUS - Server and Compute Node Only

Via RHSA-2014:2009 https://rhn.redhat.com/errata/RHSA-2014-2009.html

Comment 15 errata-xmlrpc 2014-12-18 08:23:48 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2014:2010 https://rhn.redhat.com/errata/RHSA-2014-2010.html

Comment 16 errata-xmlrpc 2014-12-22 18:51:15 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6.2 AUS

Via RHSA-2014:2028 https://rhn.redhat.com/errata/RHSA-2014-2028.html

Comment 17 errata-xmlrpc 2014-12-22 19:02:04 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 5.6 Long Life

Via RHSA-2014:2031 https://rhn.redhat.com/errata/RHSA-2014-2031.html

Comment 18 errata-xmlrpc 2014-12-22 19:14:26 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 5.9 EUS - Server Only

Via RHSA-2014:2029 https://rhn.redhat.com/errata/RHSA-2014-2029.html

Comment 19 errata-xmlrpc 2014-12-22 19:19:04 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6.4 EUS - Server and Compute Node Only

Via RHSA-2014:2030 https://rhn.redhat.com/errata/RHSA-2014-2030.html

Comment 21 errata-xmlrpc 2015-01-05 19:48:14 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 4 Extended Lifecycle Support

Via RHSA-2015:0009 https://rhn.redhat.com/errata/RHSA-2015-0009.html

Comment 26 Martin Prpič 2015-07-07 11:44:56 UTC
Detailed analysis of this issue has been posted on oss-sec:

http://seclists.org/oss-sec/2015/q3/25