Bug 749475 (CVE-2011-4081) - CVE-2011-4081 kernel: crypto: ghash: null pointer deref if no key is set
Summary: CVE-2011-4081 kernel: crypto: ghash: null pointer deref if no key is set
Alias: CVE-2011-4081
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Depends On: 749481 749482 749483 749484 761387
Blocks: 749469
TreeView+ depends on / blocked
Reported: 2011-10-27 07:44 UTC by Eugene Teo (Security Response)
Modified: 2023-05-11 18:19 UTC (History)
20 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Last Closed: 2013-04-04 01:50:57 UTC

Attachments (Terms of Use)

System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2012:0010 0 normal SHIPPED_LIVE Important: kernel-rt security and bug fix update 2012-01-11 01:14:23 UTC
Red Hat Product Errata RHSA-2012:0350 0 normal SHIPPED_LIVE Moderate: kernel security and bug fix update 2012-03-06 23:43:05 UTC

Description Eugene Teo (Security Response) 2011-10-27 07:44:34 UTC
The ghash_update function passes a pointer to gf128mul_4k_lle which will be NULL if ghash_setkey is not called or if the most recent call to ghash_setkey failed to allocate memory.  This causes an oops.  Fix this up by returning an error code in the null case.

This is trivially triggered from unprivileged userspace through the AF_ALG interface by simply writing to the socket without setting a key.

The ghash_final function has a similar issue, but triggering it requires a memory allocation failure in ghash_setkey _after_ at least one successful call to ghash_update.


Red Hat would like to thank Nick Bowler for reporting this issue.

Comment 1 Eugene Teo (Security Response) 2011-10-27 08:07:52 UTC
Upstream commit:

Comment 4 Eugene Teo (Security Response) 2011-10-27 08:10:35 UTC
Created kernel tracking bugs for this issue

Affects: fedora-all [bug 749484]

Comment 5 Eugene Teo (Security Response) 2011-10-27 08:42:26 UTC

This issue did not affect the Linux kernels as shipped with Red Hat Enterprise Linux 4, and 5 as they did not include support for the GHASH message digest algorithm. This has been addressed in Red Hat Enterprise Linux 6, and MRG via https://rhn.redhat.com/errata/RHSA-2012-0350.html, and https://rhn.redhat.com/errata/RHSA-2012-0010.html.

Comment 8 errata-xmlrpc 2012-01-10 20:16:44 UTC
This issue has been addressed in following products:

  MRG for RHEL-6 v.2

Via RHSA-2012:0010 https://rhn.redhat.com/errata/RHSA-2012-0010.html

Comment 9 errata-xmlrpc 2012-03-06 18:44:42 UTC
This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2012:0350 https://rhn.redhat.com/errata/RHSA-2012-0350.html

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