Bug 684569 (CVE-2011-0726)

Summary:	CVE-2011-0726 kernel: proc: protect mm start_code/end_code in /proc/pid/stat
Product:	[Other] Security Response	Reporter:	Eugene Teo (Security Response) <eteo>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	arozansk, bhu, branto, dhoward, jkacur, jlieskov, kernel-mgr, kmcmartin, lgoncalv, lwang, rkhan, rt-maint, tcallawa, vkrizan, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-07-29 14:08:58 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:	684570, 684571, 684572, 684573, 684574
Bug Blocks:

Description Eugene Teo (Security Response) 2011-03-13 15:15:18 UTC

While mm->start_stack was protected from cross-uid viewing (commit
f83ce3e6b02d5e48b3a43b001390e2b58820389d), the start_code and end_code
values were not. This would allow the text location of a PIE binary to
leak, defeating ASLR.

Note that the value "1" is used instead of "0" for a protected value
since "ps", "killall", and likely other readers of /proc/pid/stat, take
start_code of "0" to mean a kernel thread and will misbehave. Thanks to
Brad Spengler for pointing this out.

https://lkml.org/lkml/2011/3/11/380

Acknowledgements:

Red Hat would like to thank Kees Cook for reporting this issue.

Comment 3 Eugene Teo (Security Response) 2011-03-13 15:23:09 UTC

Statement:

Red Hat Enterprise Linux 4 is now in Production 3 of the maintenance life-cycle,
https://access.redhat.com/support/policy/updates/errata/, therefore the fix for
this issue is not currently planned to be included in the future updates. Future kernel updates in Red Hat Enterprise Linux 5, 6 and Red Hat Enterprise MRG may address this flaw.

Comment 4 Eugene Teo (Security Response) 2011-03-15 03:18:29 UTC

added to -mm tree: http://www.spinics.net/lists/mm-commits/msg82726.html

Comment 5 Eugene Teo (Security Response) 2011-04-11 03:55:27 UTC

Upstream commit:
http://git.kernel.org/linus/5883f57ca0008ffc93e09cbb9847a1928e50c6f3

Comment 6 errata-xmlrpc 2011-05-10 17:20:49 UTC

This issue has been addressed in following products:

  MRG for RHEL-5

Via RHSA-2011:0500 https://rhn.redhat.com/errata/RHSA-2011-0500.html

Comment 7 errata-xmlrpc 2011-05-10 18:11:47 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2011:0498 https://rhn.redhat.com/errata/RHSA-2011-0498.html

Comment 8 errata-xmlrpc 2011-05-31 14:06:34 UTC

This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2011:0833 https://rhn.redhat.com/errata/RHSA-2011-0833.html