(RHSA-2014:0593) Important: kernel security and bug fix 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 netfilter connection
  tracking implementation for Datagram Congestion Control Protocol (DCCP)
  packets used the skb_header_pointer() function. A remote attacker could use
  this flaw to send a specially crafted DCCP packet to crash the system or,
  potentially, escalate their privileges on the system. (CVE-2014-2523,
  Important)

• A flaw was found in the way the handle_rx() function handled large
  network packets when mergeable buffers were disabled. A privileged guest
  user could use this flaw to crash the host or corrupt QEMU process memory
  on the host, which could potentially result in arbitrary code execution on
  the host with the privileges of the QEMU process. (CVE-2014-0077, Moderate)

The CVE-2014-0077 issue was discovered by Michael S. Tsirkin of Red Hat.

This update also fixes the following bug:

• Prior to this update, a guest-provided value was used as the head length
  of the socket buffer allocated on the host. If the host was under heavy
  memory load and the guest-provided value was too large, the allocation
  could have failed, resulting in stalls and packet drops in the guest’s Tx
  path. With this update, the guest-provided value has been limited to a
  reasonable size so that socket buffer allocations on the host succeed
  regardless of the memory load on the host, and guests can send packets
  without experiencing packet drops or stalls. (BZ#1092350)

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.