SynopsisThe remote CentOS host is missing one or more security updates.
DescriptionUpdated kernel packages that fix multiple security issues and several bugs are now available for Red Hat Enterprise Linux 6.
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 futex subsystem handled the requeuing of certain Priority Inheritance (PI) futexes. A local, unprivileged user could use this flaw to escalate their privileges on the system. (CVE-2014-3153, Important)
* A flaw was found in the way the Linux kernel's floppy driver handled user space provided data in certain error code paths while processing FDRAWCMD IOCTL commands. A local user with write access to /dev/fdX could use this flaw to free (using the kfree() function) arbitrary kernel memory. (CVE-2014-1737, Important)
* It was found that the Linux kernel's floppy driver leaked internal kernel memory addresses to user space during the processing of the FDRAWCMD IOCTL command. A local user with write access to /dev/fdX could use this flaw to obtain information about the kernel heap arrangement. (CVE-2014-1738, Low)
Note: A local user with write access to /dev/fdX could use these two flaws (CVE-2014-1737 in combination with CVE-2014-1738) to escalate their privileges on the system.
* It was discovered that the proc_ns_follow_link() function did not properly return the LAST_BIND value in the last pathname component as is expected for procfs symbolic links, which could lead to excessive freeing of memory and consequent slab corruption. A local, unprivileged user could use this flaw to crash the system.
* A flaw was found in the way the Linux kernel handled exceptions when user-space applications attempted to use the linkage stack. On IBM S/390 systems, a local, unprivileged user could use this flaw to crash the system. (CVE-2014-2039, Moderate)
* An invalid pointer dereference flaw was found in the Marvell 8xxx Libertas WLAN (libertas) driver in the Linux kernel. A local user able to write to a file that is provided by the libertas driver and located on the debug file system (debugfs) could use this flaw to crash the system. Note: The debugfs file system must be mounted locally to exploit this issue. It is not mounted by default. (CVE-2013-6378, Low)
* A denial of service flaw was discovered in the way the Linux kernel's SELinux implementation handled files with an empty SELinux security context. A local user who has the CAP_MAC_ADMIN capability could use this flaw to crash the system. (CVE-2014-1874, Low)
Red Hat would like to thank Kees Cook of Google for reporting CVE-2014-3153, Matthew Daley for reporting CVE-2014-1737 and CVE-2014-1738, and Vladimir Davydov of Parallels for reporting CVE-2014-0203. Google acknowledges Pinkie Pie as the original reporter of CVE-2014-3153.
This update also fixes several bugs. Documentation for these changes will be available shortly from the Technical Notes document linked to in the References section.
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 kernel packages.