kernel security update

CentOS Errata and Security Advisory CESA-2009:1455

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

Security fix:

• a NULL pointer dereference flaw was found in the Multiple Devices (md)
  driver in the Linux kernel. If the “suspend_lo” or “suspend_hi” file on the
  sysfs file system (“/sys/”) is modified when the disk array is inactive, it
  could lead to a local denial of service or privilege escalation. Note: By
  default, only the root user can write to the files noted above.
  (CVE-2009-2849, Moderate)

Bug fixes:

• a bug in nlm_lookup_host() could lead to un-reclaimed file system locks,
  resulting in umount failing & NFS service relocation issues for clusters.
  (BZ#517967)

• a bug in the sky2 driver prevented the phy from being reset properly on
  some hardware when it hung, preventing a link from coming back up.
  (BZ#517976)

• disabling MSI-X for qla2xxx also disabled MSI interrupts. (BZ#519782)

• performance issues with reads when using the qlge driver on PowerPC
  systems. A system hang could also occur during reboot. (BZ#519783)

• unreliable time keeping for Red Hat Enterprise Linux virtual machines.
  The KVM pvclock code is now used to detect/correct lost ticks. (BZ#520685)

• /proc/cpuinfo was missing flags for new features in supported processors,
  possibly preventing the operating system & applications from getting the
  best performance. (BZ#520686)

• reading/writing with a serial loopback device on a certain IBM system did
  not work unless booted with “pnpacpi=off”. (BZ#520905)

• mlx4_core failed to load on systems with more than 32 CPUs. (BZ#520906)

• on big-endian platforms, interfaces using the mlx4_en driver & Large
  Receive Offload (LRO) did not handle VLAN traffic properly (a segmentation
  fault in the VLAN stack in the kernel occurred). (BZ#520908)

• due to a lock being held for a long time, some systems may have
  experienced “BUG: soft lockup” messages under heavy load. (BZ#520919)

• incorrect APIC timer calibration may have caused a system hang during
  boot, as well as the system time becoming faster or slower. A warning is
  now provided. (BZ#521238)

• a Fibre Channel device re-scan via ‘echo “—” > /sys/class/scsi_host/
  host[x]/scan’ may not complete after hot adding a drive, leading to soft
  lockups (“BUG: soft lockup detected”). (BZ#521239)

• the Broadcom BCM5761 network device could not to be initialized
  properly; therefore, the associated interface could not obtain an IP
  address via DHCP or be assigned one manually. (BZ#521241)

• when a process attempted to read from a page that had first been accessed
  by writing to part of it (via write(2)), the NFS client needed to flush the
  modified portion of the page out to the server, & then read the entire page
  back in. This flush caused performance issues. (BZ#521244)

• a kernel panic when using bnx2x devices & LRO in a bridge. A warning is
  now provided to disable LRO in these situations. (BZ#522636)

• the scsi_dh_rdac driver was updated to recognize the Sun StorageTek
  Flexline 380. (BZ#523237)

• in FIPS mode, random number generators are required to not return the
  first block of random data they generate, but rather save it to seed the
  repetition check. This update brings the random number generator into
  conformance. (BZ#523289)

• an option to disable/enable the use of the first random block is now
  provided to bring ansi_cprng into compliance with FIPS-140 continuous test
  requirements. (BZ#523290)

• running the SAP Linux Certification Suite in a KVM guest caused severe
  SAP kernel errors, causing it to exit. (BZ#524150)

• attempting to ‘online’ a CPU for a KVM guest via sysfs caused a system
  crash. (BZ#524151)

• when using KVM, pvclock returned bogus wallclock values. (BZ#524152)

• the clock could go backwards when using the vsyscall infrastructure.
  (BZ#524527)

See References for KBase links re BZ#519782 & BZ#520906.

Users should upgrade to these updated packages, which contain backported
patches to correct these issues. Reboot the system for this update to take
effect.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2009-October/078396.html
https://lists.centos.org/pipermail/centos-announce/2009-October/078397.html

Affected packages:
kernel
kernel-PAE
kernel-PAE-devel
kernel-debug
kernel-debug-devel
kernel-devel
kernel-doc
kernel-headers
kernel-xen
kernel-xen-devel

Upstream details at:
https://access.redhat.com/errata/RHSA-2009:1455