Security update for Xen

Open Source Vulnerabilities SUSE-SU-2015:0747-1

The Virtualization service XEN was updated to fix various bugs and security issues. The following security issues have been fixed: * CVE-2015-2756: XSA-126: Unmediated PCI command register access in qemu could have lead to denial of service attacks against the host, if PCI cards are passed through to guests. * XSA-125: Long latency MMIO mapping operations were not preemptible. * CVE-2015-2151: XSA-123: Instructions with register operands ignored eventual segment overrides encoded for them. Due to an insufficiently conditional assignment such a bogus segment override could have, however, corrupted a pointer used subsequently to store the result of the instruction. * CVE-2015-2045: XSA-122: The code handling certain sub-operations of the HYPERVISOR_xen_version hypercall failed to fully initialize all fields of structures subsequently copied back to guest memory. Due to this hypervisor stack contents were copied into the destination of the operation, thus becoming visible to the guest. * CVE-2015-2044: XSA-121: Emulation routines in the hypervisor dealing with certain system devices checked whether the access size by the guest is a supported one. When the access size is unsupported these routines failed to set the data to be returned to the guest for read accesses, so that hypervisor stack contents were copied into the destination of the operation, thus becoming visible to the guest. Also fixed: * Fully virtualized guest install from network source failed with 'cannot find guest domain' in XEN. (bsc#919341) Security Issues: * CVE-2015-2044 <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-2044> * CVE-2015-2045 <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-2045> * CVE-2015-2151 <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-2151> * CVE-2015-2756 <http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-2756>