(RHSA-2011:0017) Important: Red Hat Enterprise Linux 5.6 kernel security and bug fix update

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

This update fixes the following security issues:

• A NULL pointer dereference flaw was found in the igb driver in the Linux
  kernel. If both the Single Root I/O Virtualization (SR-IOV) feature and
  promiscuous mode were enabled on an interface using igb, it could result in
  a denial of service when a tagged VLAN packet is received on that
  interface. (CVE-2010-4263, Important)

• A missing sanity check was found in vbd_create() in the Xen hypervisor
  implementation. As CD-ROM drives are not supported by the blkback back-end
  driver, attempting to use a virtual CD-ROM drive with blkback could trigger
  a denial of service (crash) on the host system running the Xen hypervisor.
  (CVE-2010-4238, Moderate)

• A flaw was found in the Linux kernel execve() system call implementation.
  A local, unprivileged user could cause large amounts of memory to be
  allocated but not visible to the OOM (Out of Memory) killer, triggering a
  denial of service. (CVE-2010-4243, Moderate)

• A flaw was found in fixup_page_fault() in the Xen hypervisor
  implementation. If a 64-bit para-virtualized guest accessed a certain area
  of memory, it could cause a denial of service on the host system running
  the Xen hypervisor. (CVE-2010-4255, Moderate)

• A missing initialization flaw was found in the bfa driver used by Brocade
  Fibre Channel Host Bus Adapters. A local, unprivileged user could use this
  flaw to cause a denial of service by reading a file in the
  “/sys/class/fc_host/host#/statistics/” directory. (CVE-2010-4343, Moderate)

• Missing initialization flaws in the Linux kernel could lead to
  information leaks. (CVE-2010-3296, CVE-2010-3877, CVE-2010-4072,
  CVE-2010-4073, CVE-2010-4075, CVE-2010-4080, CVE-2010-4081, CVE-2010-4158,
  Low)

Red Hat would like to thank Kosuke Tatsukawa for reporting CVE-2010-4263;
Vladymyr Denysov for reporting CVE-2010-4238; Brad Spengler for reporting
CVE-2010-4243; Dan Rosenberg for reporting CVE-2010-3296, CVE-2010-4073,
CVE-2010-4075, CVE-2010-4080, CVE-2010-4081, and CVE-2010-4158; Vasiliy
Kulikov for reporting CVE-2010-3877; and Kees Cook for reporting
CVE-2010-4072.

These updated packages also include several hundred bug fixes for and
enhancements to the Linux kernel. Space precludes documenting each of these
changes in this advisory and users are directed to the Red Hat Enterprise
Linux 5.6 Release Notes for information on the most significant of these
changes:

http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/5.6_Release_Notes/index.html

Refer to the kernel chapter in the Red Hat Enterprise Linux 5.6 Technical
Notes for further information:

http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/5.6_Technical_Notes/kernel.html

All Red Hat Enterprise Linux 5 users are advised to install these updated
packages, which address these vulnerabilities as well as fixing the bugs
and adding the enhancements noted in the Red Hat Enterprise Linux 5.6
Release Notes and Technical Notes. The system must be rebooted for this
update to take effect.