This update for xen to version 4.9.2 fixes several issues. This feature was added: - Added script, udev rule and systemd service to watch for vcpu online/offline events in a HVM domU. They are triggered via "xl vcpu-set domU N" These security issues were fixed: - CVE-2018-8897: Prevent mishandling of debug exceptions on x86 - 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 - Prevent unbounded loop, induced by qemu allowing an attacker to permanently keep a physical CPU core busy - CVE-2018-10472: x86 HVM guest OS users 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 . - CVE-2018-10471: x86 PV guest OS users were able to cause a denial of service via unexpected INT 80 processing, because of an incorrect fix for CVE-2017-5754 . - CVE-2018-7540: x86 PV guest OS users were able to cause a denial of service via non-preemptable L3/L4 pagetable freeing . - CVE-2018-7541: Guest OS users were able to cause a denial of service or gain privileges by triggering a grant-table transition from v2 to v1 . - CVE-2018-7542: x86 PVH guest OS users were able to cause a denial of service by leveraging the mishandling of configurations that lack a Local APIC . These non-security issues were fixed: - bsc#1087252: Update built-in defaults for xenstored in stubdom, keep default to run xenstored as daemon in dom0 - bsc#1087251: Preserve xen-syms from xen-dbg.gz to allow processing vmcores with crash - bsc#1072834: Prevent unchecked MSR access error