(RHSA-2009:1077) Important: kernel security and bug fix update

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

This update includes backported fixes for two approved security issues.
These issues only affected users of Red Hat Enterprise Linux 4.7 Extended
Update Support, as they have already been addressed for users of Red Hat
Enterprise Linux 4 in the 4.8 update, RHSA-2009:1024.

• 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)

• the Linux kernel implementation of the Network File System (NFS) version
  4 did not properly initialize the file name limit in the nfs_server data
  structure. This flaw could possibly lead to a denial of service on a client
  mounting an NFSv4 share. (CVE-2009-1336, Moderate)

This update fixes the following bugs:

• on IBM System z systems, if the cio driver was used for DASD devices, and
  the last path to a DASD device was varied off, it was still possible to
  attempt read and write operations to that device, resulting in errors. In
  this update, path verification is used in this situation, which resolves
  this issue. Also, a bug may have caused errors when subchannels were
  unregistered. (BZ#437486)

• a bug prevented the Broadcom NetXtreme II 57710 network device from
  working correctly on some Dell PowerEdge R805 systems. This device was
  correctly shown in “lspci” output, but “ifup” failed and an IP address was
  not assigned. In this update, the device works correctly on Dell PowerEdge
  R805 systems. (BZ#491752)

Users should upgrade to these updated packages, which contain backported
patches to correct these issues. For this update to take effect, the system
must be rebooted.