Synopsis

Important: kernel-rt security and bug fix update

Type/Severity

Security Advisory: Important

Topic

Updated kernel-rt packages that fix several security issues and a bug are
now available for Red Hat Enterprise MRG 1.1.2.

This update has been rated as having important security impact by the Red
Hat Security Response Team.

Description

The kernel-rt packages contain the Linux kernel, the core of any Linux
operating system.

These updated packages fix the following security issues:

• a logic error was found in the do_setlk() function of the Linux kernel

Network File System (NFS) implementation. If a signal interrupted a lock
request, the local POSIX lock was incorrectly created. This could cause a
denial of service on the NFS server if a file descriptor was closed before
its corresponding lock request returned. (CVE-2008-4307, Important)

• a deficiency was found in the Linux kernel system call auditing

implementation on 64-bit systems. This could allow a local, unprivileged
user to circumvent a system call audit configuration, if that configuration
filtered based on the "syscall" number or arguments.
(CVE-2009-0834, Important)

• Chris Evans reported a deficiency in the Linux kernel secure-computing

implementation on 64-bit systems. This could allow a local, unprivileged
user to bypass intended access restrictions, if those access restriction
filters were based on the "syscall" number or arguments.
(CVE-2009-0835, Important)

• the exit_notify() function in the Linux kernel did not properly reset the

exit signal if a process executed a set user ID (setuid) application before
exiting. This could allow a local, unprivileged user to elevate their
privileges. (CVE-2009-1337, Important)

• Chris Evans reported a deficiency in the Linux kernel signals

implementation. The clone() system call permits the caller to indicate the
signal it wants to receive when its child exits. When clone() is called
with the CLONE_PARENT flag, it permits the caller to clone a new child that
shares the same parent as itself, enabling the indicated signal to be sent
to the caller's parent (instead of the caller), even if the caller's parent
has different real and effective user IDs. This could lead to a denial of
service of the parent. (CVE-2009-0028, Moderate)

• an off-by-two error was found in the set_selection() function of the

Linux kernel. This could allow a local, unprivileged user to cause a denial
of service when making a selection of characters in a UTF-8 console. Note:
physical console access is required to exploit this issue.
(CVE-2009-1046, Low)

These updated packages also fix the following bug:

• the __scsi_device_lookup_by_target() function was always returning the

first matching device, regardless of the state of the device. This meant
that any valid device listed after a deleted device would not be found. The
__scsi_device_lookup_by_target() function was modified so that deleted
devices are skipped, and valid devices are now found. (BZ#495976)

All Red Hat Enterprise MRG users should install this update, which resolves
these issues. For this update to take effect, the system must be rebooted.

Solution

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

This update is available via 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

• MRG Realtime 1 x86_64
• MRG Realtime 1 i386

Fixes

• BZ - 456282 - CVE-2008-4307 Kernel BUG() in locks_remove_flock
• BZ - 479932 - CVE-2009-0028 Linux kernel minor signal handling vulnerability
• BZ - 487255 - CVE-2009-0835 kernel: x86-64: seccomp: 32/64 syscall hole
• BZ - 487990 - CVE-2009-0834 kernel: x86-64: syscall-audit: 32/64 syscall hole
• BZ - 491787 - CVE-2009-1046 kernel: utf8 selection memory corruption
• BZ - 493771 - CVE-2009-1337 kernel: exit_notify: kill the wrong capable(CAP_KILL) check

CVEs

• CVE-2009-0028
• CVE-2009-1046
• CVE-2009-1337
• CVE-2008-4307
• CVE-2009-0834
• CVE-2009-0835

References