The kernel packages contain the Linux kernel, the core of any Linux operating system. * It was found that the Linux kernel"s Infiniband subsystem did not properly sanitize input parameters while registering memory regions from user space via the 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. * An insufficient bound checking flaw was found in the Xen hypervisor"s implementation of acceleration support for the "REP MOVS" instructions. A privileged HVM guest user could potentially use this flaw to crash the host. Red Hat would like to thank Mellanox for reporting CVE-2014-8159, and the Xen project for reporting CVE-2014-8867. This update also fixes the following bugs: * Under memory pressure, cached data was previously flushed to the backing server using the PID of the thread responsible for flushing the data in the Server Message Block headers instead of the PID of the thread which actually wrote the data. As a consequence, when a file was locked by the writing thread prior to writing, the server considered writes by the thread flushing the pagecache as being a separate process from writing to a locked file, and thus rejected the writes. In addition, the data to be written was discarded. This update ensures that the correct PID is sent to the server, and data corruption is avoided when data is being written from a client under memory pressure. * This update adds support for new cryptographic hardware in toleration mode for IBM System z. 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.