RHSA-2010:0521 - Security Advisory

Topic

Updated gfs-kmod packages that fix one security issue are now available for
Red Hat Enterprise Linux 5.4 Extended Update Support, kernel release
2.6.18-164.19.1.el5.

The Red Hat Security Response Team has rated this update as having moderate
security impact. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available from the CVE link in
the References section.

Description

The gfs-kmod packages contain modules that provide the ability to mount and
use GFS file systems.

A flaw was found in the gfs_lock() implementation. The GFS locking code
could skip the lock operation for files that have the S_ISGID bit
(set-group-ID on execution) in their mode set. A local, unprivileged user
on a system that has a GFS file system mounted could use this flaw to cause
a kernel panic. (CVE-2010-0727)

These updated gfs-kmod packages are in sync with the latest kernel
(2.6.18-164.19.1.el5). The modules in earlier gfs-kmod packages failed to
load because they did not match the running kernel. It was possible to
force-load the modules. With this update, however, users no longer need to.

Users are advised to upgrade to these latest gfs-kmod packages, updated for
use with the 2.6.18-164.19.1.el5 kernel, which contain a backported patch
to correct this issue.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Resilient Storage for x86_64 - Extended Update Support 5.4 x86_64
• Red Hat Enterprise Linux Resilient Storage for x86_64 - Extended Update Support 5.4 ppc
• Red Hat Enterprise Linux Resilient Storage for x86_64 - Extended Update Support 5.4 ia64
• Red Hat Enterprise Linux Resilient Storage for x86_64 - Extended Update Support 5.4 i386

Fixes

• BZ - 570863 - CVE-2010-0727 bug in GFS/GFS2 locking code leads to dos

CVEs

• CVE-2010-0727

References

• http://www.redhat.com/security/updates/classification/#moderate