Security update for xen (important)

This update for xen fixes several issues:

These security issues were fixed:

• CVE-2017-5526: The ES1370 audio device emulation support was vulnerable
  to a memory leakage issue allowing a privileged user inside the guest to
  cause a DoS and/or potentially crash the Qemu process on the host
  (bsc#1059777)
• CVE-2017-15593: Missing cleanup in the page type system allowed a
  malicious or buggy PV guest to cause DoS (XSA-242 bsc#1061084)
• CVE-2017-15592: A problem in the shadow pagetable code allowed a
  malicious or buggy HVM guest to cause DoS or cause hypervisor memory
  corruption potentially allowing the guest to escalate its privilege
  (XSA-243 bsc#1061086)
• CVE-2017-15594: Problematic handling of the selector fields in the
  Interrupt Descriptor Table (IDT) allowed a malicious or buggy x86 PV
  guest to escalate its privileges or cause DoS (XSA-244 bsc#1061087)
• CVE-2017-15589: Intercepted I/O write operations with less than a full
  machine word’s worth of data were not properly handled, which allowed a
  malicious unprivileged x86 HVM guest to obtain sensitive information
  from the host or
  other guests (XSA-239 bsc#1061080)
• CVE-2017-15595: In certain configurations of linear page tables a stack
  overflow might have occured that allowed a malicious or buggy PV guest
  to cause DoS and potentially privilege escalation and information leaks
  (XSA-240 bsc#1061081)
• CVE-2017-15588: Under certain conditions x86 PV guests could have caused
  the hypervisor to miss a necessary TLB flush for a page. This allowed a
  malicious x86 PV guest to access all of system memory, allowing for
  privilege escalation, DoS, and information leaks (XSA-241 bsc#1061082)
• CVE-2017-15590: Multiple issues existed with the setup of PCI MSI
  interrupts that allowed a malicious or buggy guest to cause DoS and
  potentially privilege escalation and information leaks (XSA-237
  bsc#1061076)