Security update for xen (important)

This update for xen fixes several issues.

These security issues were fixed:

• CVE-2017-12135: Unbounded recursion in grant table code allowed a
  malicious guest to crash the host or potentially escalate
  privileges/leak information (XSA-226, bsc#1051787).
• CVE-2017-12137: Incorrectly-aligned updates to pagetables allowed for
  privilege escalation (XSA-227, bsc#1051788).
• CVE-2017-11334: The address_space_write_continue function in exec.c
  allowed local guest OS privileged users to cause a denial of service
  (out-of-bounds access and guest instance crash) by leveraging use of
  qemu_map_ram_ptr to access guest ram block area (bsc#1048920).
• CVE-2017-11434: The dhcp_decode function in slirp/bootp.c allowed local
  guest OS users to cause a denial of service (out-of-bounds read) via a
  crafted DHCP
  options string (bsc#1049578).
• CVE-2017-10806: Stack-based buffer overflow in hw/usb/redirect.c allowed
  local guest OS users to cause a denial of service via vectors related to
  logging debug messages (bsc#1047675).
• CVE-2017-10664: qemu-nbd did not ignore SIGPIPE, which allowed remote
  attackers to cause a denial of service (daemon crash) by disconnecting
  during a server-to-client reply attempt (bsc#1046637).
• CVE-2017-12855: Premature clearing of GTF_writing / GTF_reading lead to
  potentially leaking sensitive information (XSA-230, bsc#1052686).
• CVE-2017-14316: Missing bound check in function alloc_heap_pages for
  an internal array allowed attackers using crafted hypercalls to execute
  arbitrary code within Xen (XSA-231, bsc#1056278)
• CVE-2017-14317: A race in cxenstored may have cause a double-free
  allowind for DoS of the xenstored daemon (XSA-233, bsc#1056281).
• CVE-2017-14319: An error while handling grant mappings allowed malicious
  or buggy x86 PV guest to escalate its privileges or crash the hypervisor
  (XSA-234, bsc#1056282).

This non-security issue was fixed:

• bsc#1032598: Prevent removal of NVME devices
• bsc#1037413: Support for newer intel cpu’s, mwait-idle driver and skylake