Security update for xen

Open Source Vulnerabilities SUSE-SU-2018:1203-1

This update for xen fixes several issues. These security issues were fixed: - CVE-2018-8897: Prevent mishandling of debug exceptions on x86 (XSA-260, bsc#1090820) - Handle HPET timers in IO-APIC mode correctly to prevent malicious or buggy HVM guests from causing a hypervisor crash or potentially privilege escalation/information leaks (XSA-261, bsc#1090822) - Prevent unbounded loop, induced by qemu allowing an attacker to permanently keep a physical CPU core busy (XSA-262, bsc#1090823) - CVE-2018-10472: x86 HVM guest OS users (in certain configurations) were able to read arbitrary dom0 files via QMP live insertion of a CDROM, in conjunction with specifying the target file as the backing file of a snapshot (bsc#1089152). - CVE-2018-10471: x86 PV guest OS users were able to cause a denial of service (out-of-bounds zero write and hypervisor crash) via unexpected INT 80 processing, because of an incorrect fix for CVE-2017-5754 (bsc#1089635). - CVE-2018-7550: The load_multiboot function allowed local guest OS users to execute arbitrary code on the host via a mh_load_end_addr value greater than mh_bss_end_addr, which triggers an out-of-bounds read or write memory access (bsc#1083292).