The kernel packages contain the Linux kernel, the core of any Linux operating system.
This update fixes the following security issues:
Note: For Red Hat Enterprise Linux guests, only privileged guest users can exploit CVE-2012-0217.
If you do not run applications that use xfrm6_tunnel, you can prevent the xfrm6_tunnel module from being loaded by creating (as the root user) a "/etc/modprobe.d/xfrm6_tunnel.conf" file, and adding the following line to it:
This way, the xfrm6_tunnel module cannot be loaded accidentally. A reboot is not necessary for this change to take effect.
Red Hat would like to thank the Xen project for reporting CVE-2012-0217. Upstream acknowledges Rafal Wojtczuk as the original reporter of CVE-2012-0217.
This update also fixes the following bugs:
A bug in the vsyscall interface caused 32-bit multi-threaded programs, which received the SIGCANCEL signal right after they returned from a system call, to terminate unexpectedly with a segmentation fault when run on the AMD64 or Intel 64 architecture. A patch has been provided to address this issue and the crashes no longer occur in the described scenario. (BZ#807929)
Incorrect duplicate MAC addresses were being used on a rack network daughter card that contained a quad-port Intel I350 Gigabit Ethernet Controller. With this update, the underlying source code has been modified to address this issue, and correct MAC addresses are now used under all circumstances. (BZ#813195)
When the Fibre Channel (FC) layer sets a device to "running", the layer also scans for other new devices. Previously, there was a race condition between these two operations. Consequently, for certain targets, thousands of invalid devices were created by the SCSI layer and the udev service. This update ensures that the FC layer always sets a device to "online" before scanning for others, thus fixing this bug.
Additionally, when attempting to transition priority groups on a busy FC device, the multipath layer retried immediately. If this was the only available path, a large number of retry operations were performed in a short period of time. Consequently, the logging of retry messages slowed down the system. This bug has been fixed by ensuring that the DM Multipath feature delays retry operations in the described scenario. (BZ#816683)
Users should upgrade to these updated packages, which contain backported patches to correct these issues. The system must be rebooted for this update to take effect.