[RHSA-2015:1978] kernel security, bug fix, and enhancement update

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

• A flaw was found in the way the Linux kernel's VFS subsystem handled file
  system locks. A local, unprivileged user could use this flaw to trigger a
  deadlock in the kernel, causing a denial of service on the system.
  (CVE-2014-8559, Moderate)

• A buffer overflow flaw was found in the way the Linux kernel's virtio-net
  subsystem handled certain fraglists when the GRO (Generic Receive Offload)
  functionality was enabled in a bridged network configuration. An attacker
  on the local network could potentially use this flaw to crash the system,
  or, although unlikely, elevate their privileges on the system.
  (CVE-2015-5156, Moderate)

The CVE-2015-5156 issue was discovered by Jason Wang of Red Hat.

This update also fixes several bugs and adds one enhancement. Refer to the
following Knowledgebase article for further information:

https://access.redhat.com/articles/2039563

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