RHEL 6 : kernel (RHSA-2014:0593)
Critical Nessus Plugin ID 79024
SynopsisThe remote Red Hat host is missing one or more security updates.
DescriptionUpdated kernel packages that fix two security issues and one bug are now available for Red Hat Enterprise Linux 6.3 Extended Update Support.
The Red Hat Security Response Team has rated this update as having Important security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.
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.
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.
SolutionUpdate the affected packages.