Bug 481604 (CVE-2009-0269) - CVE-2009-0269 kernel: ecryptfs readlink flaw
Summary: CVE-2009-0269 kernel: ecryptfs readlink flaw
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2009-0269
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
high
high
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL: http://nvd.nist.gov/nvd.cfm?cvename=C...
Whiteboard:
Depends On: 481605 481606 481607
Blocks:
TreeView+ depends on / blocked
 
Reported: 2009-01-26 17:59 UTC by Mark J. Cox
Modified: 2022-04-20 13:00 UTC (History)
16 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed: 2011-09-30 22:00:53 UTC
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2009:0326 0 normal SHIPPED_LIVE Important: kernel security and bug fix update 2009-04-01 08:28:02 UTC
Red Hat Product Errata RHSA-2009:0360 0 normal SHIPPED_LIVE Important: kernel-rt security and bug fix update 2009-03-27 00:15:06 UTC

Description Mark J. Cox 2009-01-26 17:59:07 UTC
Common Vulnerabilities and Exposures assigned an identifier CVE-2009-0269 to the following vulnerability:

fs/ecryptfs/inode.c in the eCryptfs subsystem in the Linux kernel before 2.6.28.1 allows local users to cause a denial of service (fault or memory corruption), or possibly have unspecified other impact, via a readlink call that results in an error, leading to use of a -1 return value as an array index.

Hyperlink:https://lists.launchpad.net/ecryptfs-devel/msg00011.html  
Hyperlink:https://lists.launchpad.net/ecryptfs-devel/msg00010.html  
Hyperlink:http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.27.y.git;a=commit;h=a17d5232de7b53d34229de79ec22f4bb04adb7e4

Comment 3 Mark J. Cox 2009-01-27 10:29:06 UTC
So based on a quick technical first pass on the affected code:

- it can only affect systems that are using and have mounted a ecryptfs directory, and allow such to be done by unprivileged users
- the local attacker would need to be able to make a readlink on a symlink fail, most likely permissions, or perhaps too many symlinks. 
- the outcome would be writing a single null byte one memory address before the kmalloc()ed buffer.

Some sites are writing up this issue as a privilege escalation flaw, but I believe that given the circumstances this is most unlikely.  Setting severity to moderate and requesting review from a kernel engineer.

Comment 4 Eric Sandeen 2009-02-04 16:02:27 UTC
Mark, I concur with your severity analysis.

Patch sent to rhkernel-list on 2/4/2009 (sorry for the delay...)

-Eric

Comment 7 errata-xmlrpc 2009-03-27 00:15:25 UTC
This issue has been addressed in following products:

  MRG for RHEL-5

Via RHSA-2009:0360 https://rhn.redhat.com/errata/RHSA-2009-0360.html

Comment 8 errata-xmlrpc 2009-04-01 08:32:24 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2009:0326 https://rhn.redhat.com/errata/RHSA-2009-0326.html

Comment 9 Jan Tluka 2009-07-20 15:46:40 UTC
Patch is in -158.el5. Adding SanityOnly.


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