RHEL 6 : kernel-rt (RHSA-2014:1943)
Medium Nessus Plugin ID 79684
SynopsisThe remote Red Hat host is missing one or more security updates.
DescriptionUpdated kernel-rt packages that fix three security issues, several bugs, and add various enhancements are now available for Red Hat Enterprise MRG 2.5.
Red Hat Product Security has rated this update as having Moderate 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-rt packages contain the Linux kernel, the core of any Linux operating system.
* A denial of service flaw was found in the way the Linux kernel's XFS file system implementation ordered directory hashes under certain conditions. A local attacker could use this flaw to corrupt the file system by creating directories with colliding hash values, potentially resulting in a system crash. (CVE-2014-7283, Moderate)
* An out-of-bounds memory access flaw was found in the syscall tracing functionality of the Linux kernel's perf subsystem. A local, unprivileged user could use this flaw to crash the system. (CVE-2014-7825, Moderate)
* An out-of-bounds memory access flaw was found in the syscall tracing functionality of the Linux kernel's ftrace subsystem. On a system with ftrace syscall tracing enabled, a local, unprivileged user could use this flaw to crash the system, or escalate their privileges. (CVE-2014-7826, Moderate)
The kernel-rt packages have been upgraded to upstream version 3.10.58, which provides a number of bug fixes and enhancements over the previous version. (BZ#1158105)
This update also fixes the following bugs :
* Automatic NUMA balancing on a low priority thread could cause memory contention with a high priority thread running in the same process. This contention could trigger poor real time performance on the system. In order to avoid this potential memory contention, the MRG Realtime kernel now disables NUMA_BALANCING_DEFAULT_ENABLED. (BZ#1158940)
* When tracing a bug, WARN*() functions could flood the ring buffer making the trace useless or even overflowing the ring buffer. To address this issue, a traceoff_on_warning option was added to the kernel command line and as a sysctl option. This option disables the writing of the warning messages to the ring buffer, which results in a cleaner trace for debugging.
In addition, this update adds the following enhancement :
* Support for XHCI (USB 3) is now enabled in the MRG Realtime kernel. (BZ#1134095)
All kernel-rt users are advised to upgrade to these updated packages, which contain correct these issues and add these enhancements. The system must be rebooted for this update to take effect.
SolutionUpdate the affected packages.