4.7 - RHSA-2009:0451

Problem Description:

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.

2. Relevant releases/architectures:

MRG Realtime for RHEL 5 Server - i386, noarch, x86_64

3. 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.

4. 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

5. Bugs fixed (http://bugzilla.redhat.com/):

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