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)
• bsc#1061084: Missing cleanup in the page type system allowed a malicious
  or buggy PV guest to cause DoS (XSA-242)
• bsc#1061086: 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#1061087: 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#1061077 Missing checks in the handling of DMOPs allowed malicious or
  buggy stub domain kernels or tool stacks otherwise living outside of
  Domain0 to cause a DoS (XSA-238)
• bsc#1061080: 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#1061081: 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#1061082: 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#1061076: 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#1055321: When dealing with the grant map space of add-to-physmap
  operations, ARM specific code failed to release a lock. This allowed a
  malicious guest administrator to cause DoS (XSA-235)