Share your story
The central voice for Linux and Open Source security news
Home News Topics Advisories HOWTOs Features Newsletters About Register

Sign up!
EnGarde Community
What is the most important Linux security technology?
Linux Events
Linux User Groups
Link to Us
Security Center
Book Reviews
Security Dictionary
Security Tips
White Papers
Featured Blogs
All About Linux
DanWalsh LiveJournal
Latest Newsletters
Linux Security Week: March 23rd, 2015
Linux Advisory Watch: March 20th, 2015
LinuxSecurity Newsletters
Choose Lists:
About our Newsletters
RSS Feeds
Get the LinuxSecurity news you want faster with RSS
Powered By

Red Hat: 2010:0291-04: gfs-kmod: Moderate Advisory Print E-mail
User Rating:      How can I rate this item?
Posted by Benjamin D. Thomas   
RedHat Linux Updated gfs-kmod packages that fix one security issue, numerous bugs, and add one enhancement are now available for Red Hat Enterprise Linux 5.5, kernel release 2.6.18-194.el5. [More...]
                   Red Hat Security Advisory

Synopsis:          Moderate: gfs-kmod security, bug fix and enhancement update
Advisory ID:       RHSA-2010:0291-04
Product:           Red Hat Enterprise Linux
Advisory URL:
Issue date:        2010-03-30
CVE Names:         CVE-2010-0727 

1. Summary:

Updated gfs-kmod packages that fix one security issue, numerous bugs, and
add one enhancement are now available for Red Hat Enterprise Linux 5.5,
kernel release 2.6.18-194.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.

2. Relevant releases/architectures:

RHEL Cluster-Storage (v. 5 server) - i386, ia64, ppc, x86_64

3. 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
(2.6.18-194.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.

These updated gfs-kmod packages also fix the following bugs:

* when SELinux was in permissive mode, a race condition during file
creation could have caused one or more cluster nodes to be fenced and lock
the remaining nodes out of the GFS file system. This race condition no
longer occurs with this update. (BZ#471258)

* when ACLs (Access Control Lists) are enabled on a GFS file system, if a
transaction that has started to do a write request does not have enough
spare blocks for the operation it causes a kernel panic. This update
ensures that there are enough blocks for the write request before starting
the operation. (BZ#513885)

* requesting a "flock" on a file in GFS in either read-only or read-write
mode would sometimes cause a "Resource temporarily unavailable" state error
(error 11 for EWOULDBLOCK) to occur. In these cases, a flock could not be
obtained on the file in question. This has been fixed with this update so
that flocks can successfully be obtained on GFS files without this error
occurring. (BZ#515717)

* the GFS withdraw function is a data integrity feature of GFS file systems
in a cluster. If the GFS kernel module detects an inconsistency in a GFS
file system following an I/O operation, the file system becomes unavailable
to the cluster. The GFS withdraw function is less severe than a kernel
panic, which would cause another node to fence the node. With this update,
you can override the GFS withdraw function by mounting the file system with
the "-o errors=panic" option specified. When this option is specified, any
errors that would normally cause the system to withdraw cause the system to
panic instead. This stops the node's cluster communications, which causes
the node to be fenced. (BZ#517145)

Finally, these updated gfs-kmod packages provide the following enhancement:

* the GFS kernel modules have been updated to use the new generic freeze
and unfreeze ioctl interface that is also supported by the following file
systems: ext3, ext4, GFS2, JFS and ReiserFS. With this update, GFS supports
freeze/unfreeze through the VFS-level FIFREEZE/FITHAW ioctl interface.

Users are advised to upgrade to these latest gfs-kmod packages, updated for
use with the 2.6.18-194.el5 kernel, which contain backported patches to
correct these issues, fix these bugs, and add this enhancement.

4. 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

5. Bugs fixed (

471258 - fatal: assertion "gfs_glock_is_locked_by_me(gl) && gfs_glock_is_held_excl(gl)" failed
487610 - GFS: Change gfs freeze/unfreeze to use new standard
513885 - GFS kernel panic, suid + nfsd with posix ACLs enabled
515717 - Flock on GFS fs file will error with "Resource tempory unavailable" for EWOULDBLOCK
517145 - [RFE] GFS: New mount option: -o errors=withdraw|panic
570863 - CVE-2010-0727 bug in GFS/GFS2 locking code leads to dos

6. Package List:

RHEL Cluster-Storage (v. 5 server):






These packages are GPG signed by Red Hat for security.  Our key and 
details on how to verify the signature are available from

7. References:

8. Contact:

The Red Hat security contact is .  More contact
details at

Copyright 2010 Red Hat, Inc.
< Prev   Next >


Latest Features
Peter Smith Releases Linux Network Security Online
Securing a Linux Web Server
Password guessing with Medusa 2.0
Password guessing as an attack vector
Squid and Digest Authentication
Squid and Basic Authentication
Demystifying the Chinese Hacking Industry: Earning 6 Million a Night
Free Online security course (LearnSIA) - A Call for Help
What You Need to Know About Linux Rootkits
Review: A Practical Guide to Fedora and Red Hat Enterprise Linux - Fifth Edition
Yesterday's Edition
Tech Companies, Privacy Advocates Call for NSA Reform
Google warns of unauthorized TLS certificates trusted by almost all OSes
How Kevin Mitnick hacked the audience at CeBIT 2015
Partner Sponsor

Community | HOWTOs | Blogs | Features | Book Reviews | Networking
 Security Projects |  Latest News |  Newsletters |  SELinux |  Privacy |  Home
 Hardening |   About Us |   Advertise |   Legal Notice |   RSS |   Guardian Digital
(c)Copyright 2015 Guardian Digital, Inc. All rights reserved.