Synopsis

Moderate: gfs-kmod security, bug fix and enhancement update

Type/Severity

Security Advisory: Moderate

Topic

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.

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.
  (BZ#487610)
  

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.

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 RHEL Server) 5 x86_64
• Red Hat Enterprise Linux Resilient Storage (for RHEL Server) 5 ppc
• Red Hat Enterprise Linux Resilient Storage (for RHEL Server) 5 ia64
• Red Hat Enterprise Linux Resilient Storage (for RHEL Server) 5 i386
• Red Hat Enterprise Linux Resilient Storage (for RHEL Server) from RHUI 5 x86_64
• Red Hat Enterprise Linux Resilient Storage (for RHEL Server) from RHUI 5 i386

Fixes

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

Red Hat Enterprise Linux Resilient Storage (for RHEL Server) 5

SRPM
gfs-kmod-0.1.34-12.el5.src.rpm	SHA-256: b2d0f93451cb54952d0721d89b5b3f0299de268c33119965230e4b7ecb82bc19
x86_64
kmod-gfs-0.1.34-12.el5.x86_64.rpm	SHA-256: 654cf89fe5729078f865358f83b76b036cf17435c7826daa5343b0e18b685854
kmod-gfs-xen-0.1.34-12.el5.x86_64.rpm	SHA-256: 83f1bdce69f52a033cc501c43063d173c7254864676112d45c99ebcca9d48fb8
ppc
kmod-gfs-0.1.34-12.el5.ppc64.rpm	SHA-256: 879ca6c292ea399d0925d9d049154570fb9e39c27a0b92315bfbf0a96bcb0b92
ia64
kmod-gfs-0.1.34-12.el5.ia64.rpm	SHA-256: 9c23a4e6454fd8e351670a22297ab9cd1ba28e5f6f7d6ec22a26c19302d3aba7
kmod-gfs-xen-0.1.34-12.el5.ia64.rpm	SHA-256: aee3dd6856bba995f589fc1d5a867765d28fe2b1c92e2a0c02a50c3ee4e9d8f2
i386
kmod-gfs-0.1.34-12.el5.i686.rpm	SHA-256: 9e7576fd8e1b29890a92c0523ac756e5ee3f1b18928c78aabc812ec6624cc7b7
kmod-gfs-PAE-0.1.34-12.el5.i686.rpm	SHA-256: 791aa9ed2f6f0a86f38635f5f39233da671d34083538c39206cbdd2fcb338cc1
kmod-gfs-xen-0.1.34-12.el5.i686.rpm	SHA-256: 27c6f10d5a8bc39249eba12e35e5948c997357a0931810f8a9991d154559eaf1

Red Hat Enterprise Linux Resilient Storage (for RHEL Server) from RHUI 5

SRPM
gfs-kmod-0.1.34-12.el5.src.rpm	SHA-256: b2d0f93451cb54952d0721d89b5b3f0299de268c33119965230e4b7ecb82bc19
x86_64
kmod-gfs-0.1.34-12.el5.x86_64.rpm	SHA-256: 654cf89fe5729078f865358f83b76b036cf17435c7826daa5343b0e18b685854
kmod-gfs-xen-0.1.34-12.el5.x86_64.rpm	SHA-256: 83f1bdce69f52a033cc501c43063d173c7254864676112d45c99ebcca9d48fb8
i386
kmod-gfs-0.1.34-12.el5.i686.rpm	SHA-256: 9e7576fd8e1b29890a92c0523ac756e5ee3f1b18928c78aabc812ec6624cc7b7
kmod-gfs-PAE-0.1.34-12.el5.i686.rpm	SHA-256: 791aa9ed2f6f0a86f38635f5f39233da671d34083538c39206cbdd2fcb338cc1
kmod-gfs-xen-0.1.34-12.el5.i686.rpm	SHA-256: 27c6f10d5a8bc39249eba12e35e5948c997357a0931810f8a9991d154559eaf1