RHSA-2015:0803: Important: kernel security and bug fix update

The kernel packages contain the Linux kernel, the core of any Linuxoperating system. It was found that the Linux kernel's Infiniband subsystem did not properly sanitize input parameters while registering memory regions fromuser space via the (u)verbs API. A local user with access to a/dev/infiniband/uverbsX device could use this flaw to crash the system or,potentially, escalate their privileges on the system. (CVE-2014-8159,Important) An integer overflow flaw was found in the way the Linux kernel's Frame Buffer device implementation mapped kernel memory to user space via themmap syscall. A local user able to access a frame buffer device file(/dev/fb) could possibly use this flaw to escalate their privileges on thesystem. (CVE-2013-2596, Important) It was found that the parserockridgeinodeinternal() function of the Linux kernel's ISOFS implementation did not correctly check relocateddirectories when processing Rock Ridge child link (CL) tags. An attackerwith physical access to the system could use a specially crafted ISO imageto crash the system or, potentially, escalate their privileges on thesystem. (CVE-2014-5471, CVE-2014-5472, Low)Red Hat would like to thank Mellanox for reporting the CVE-2014-8159 issue.This update also fixes the following bugs: The kernel could sometimes panic due to a possible division by zero in the kernel scheduler. This bug has been fixed by defining a new div64ul()division function and correcting the affected calculation in theprocschedshowtask() function. (BZ#1199898) When repeating a Coordinated Universal Time (UTC) value during a leap second (when the UTC time should be 23:59:60), the International AtomicTime (TAI) timescale previously stopped as the kernel NTP code incrementedthe TAI offset one second too late. A patch has been provided, which fixesthe bug by incrementing the offset during the leap second itself. Now, thecorrect TAI is set during the leap second. (BZ#1201672)All kernel users are advised to upgrade to these updated packages, whichcontain backported patches to correct these issues. The system must berebooted for this update to take effect.