kernel security update

CentOS Errata and Security Advisory CESA-2015:0783

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

• It was found that the Linux kernel’s Infiniband subsystem did not
  properly sanitize input parameters while registering memory regions from
  user space via the (u)verbs API. A local user with access to a
  /dev/infiniband/uverbsX device could use this flaw to crash the system or,
  potentially, escalate their privileges on the system. (CVE-2014-8159,
  Important)

• An insufficient bound checking flaw was found in the Xen hypervisor’s
  implementation of acceleration support for the “REP MOVS” instructions.
  A privileged HVM guest user could potentially use this flaw to crash the
  host. (CVE-2014-8867, Important)

Red Hat would like to thank Mellanox for reporting CVE-2014-8159, and the
Xen project for reporting CVE-2014-8867.

This update also fixes the following bugs:

• Under memory pressure, cached data was previously flushed to the backing
  server using the PID of the thread responsible for flushing the data in the
  Server Message Block (SMB) headers instead of the PID of the thread which
  actually wrote the data. As a consequence, when a file was locked by the
  writing thread prior to writing, the server considered writes by the thread
  flushing the pagecache as being a separate process from writing to a locked
  file, and thus rejected the writes. In addition, the data to be written was
  discarded. This update ensures that the correct PID is sent to the server,
  and data corruption is avoided when data is being written from a client
  under memory pressure. (BZ#1169304)

• This update adds support for new cryptographic hardware in toleration
  mode for IBM System z. (BZ#1182522)

All kernel users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. The system must be
rebooted for this update to take effect.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2015-April/083218.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-2015:0783