(RHSA-2009:0451) Important: kernel-rt security and bug fix update

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.