This update for xen fixes the following issues: - CVE-2018-17963: qemu_deliver_packet_iov accepted packet sizes greater than INT_MAX, which allows attackers to cause a denial of service or possibly have unspecified other impact. - CVE-2018-15468: The DEBUGCTL MSR contains several debugging features, some of which virtualise cleanly, but some do not. In particular, Branch Trace Store is not virtualised by the processor, and software has to be careful to configure it suitably not to lock up the core. As a result, it must only be available to fully trusted guests. Unfortunately, in the case that vPMU is disabled, all value checking was skipped, allowing the guest to choose any MSR_DEBUGCTL setting it likes. A malicious or buggy guest administrator could have locked up the entire host, causing a Denial of Service. Non security issues fixed: - Kernel oops in fs/dcache.c called by d_materialise_unique