Red Hat 6.3: RHSA-2013:1783-01 Important Kernel Update: Critical Issues

The kernel packages contain the Linux kernel, the core of any Linux operating system.
* A race condition was found in the way asynchronous I/O and fallocate() interacted when using the ext4 file system. A local, unprivileged user could use this flaw to expose random data from an extent whose data blocks have not yet been written, and thus contain data from a deleted file. (CVE-2012-4508, Important)
* An information leak flaw was found in the way the Linux kernel's device mapper subsystem, under certain conditions, interpreted data written to snapshot block devices. An attacker could use this flaw to read data from disk blocks in free space, which are normally inaccessible. (CVE-2013-4299, Moderate)
* A format string flaw was found in the Linux kernel's block layer. A privileged, local user could potentially use this flaw to escalate their privileges to kernel level (ring0). (CVE-2013-2851, Low)
Red Hat would like to thank Theodore Ts'o for reporting CVE-2012-4508, Fujitsu for reporting CVE-2013-4299, and Kees Cook for reporting CVE-2013-2851. Upstream acknowledges Dmitry Monakhov as the original reporter of CVE-2012-4508.
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.