Bug 1031678 (CVE-2013-4591)

Summary: CVE-2013-4591 kernel: nfs: missing check for buffer length in __nfs4_get_acl_uncached
Product: [Other] Security Response Reporter: Petr Matousek <pmatouse>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: agordeev, aquini, bhu, davej, dhoward, esammons, fhrbata, gansalmon, gbarros, iboverma, itamar, jforbes, jkacur, jkurik, jonathan, jross, jwboyer, kernel-maint, kernel-mgr, lgoncalv, lwang, madhu.chinakonda, matt, mcressma, nobody, pholasek, plougher, rt-maint, rvrbovsk, vkrizan, williams
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard: impact=moderate,public=20121211,reported=20130130,source=git,cvss2=6.2/AV:L/AC:H/Au:N/C:C/I:C/A:C,rhel-5/kernel=notaffected,rhel-6/kernel=affected,rhel-7/kernel=notaffected,mrg-2/realtime-kernel=notaffected,fedora-all/kernel=notaffected,rhel-6.4.z/kernel=affected
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2014-06-24 12:54:56 EDT Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---
Bug Depends On: 906056, 1052136    
Bug Blocks: 1031681    

Description Petr Matousek 2013-11-18 09:29:50 EST 
Commit 1f1ea6c (included in Red Hat Enterprise Linux 6 as part of CVE-2012-2375 fix) accidently dropped the checking for too small result buffer length.
   
If someone uses getxattr on "system.nfs4_acl" on an NFSv4 mount supporting ACLs, the ACL has not been cached and the buffer suplied is too short, we still copy the complete ACL, resulting in kernel and user space memory corruption.

Introduced by:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=1f1ea6c2d9d8c0be9ec56454b05315273b5de8ce

Upstream commit:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=7d3e91a89b7adbc2831334def9e494dd9892f9af
Comment 1 Petr Matousek 2013-11-18 09:32:43 EST 
Statement:

This issue did not affect the version of Linux kernel as shipped with Red Hat Enterprise Linux 5 and Red Hat Enterprise MRG 2.
Comment 2 errata-xmlrpc 2013-11-21 15:36:56 EST 
This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2013:1645 https://rhn.redhat.com/errata/RHSA-2013-1645.html
Comment 4 errata-xmlrpc 2014-03-11 13:08:04 EDT 
This issue has been addressed in following products:

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

Via RHSA-2014:0284 https://rhn.redhat.com/errata/RHSA-2014-0284.html