This update for xen fixes several issues.

These security issues were fixed:

- 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-2017-14318: The function __gnttab_cache_flush missed a check for grant
tables, allowing a malicious guest to crash the host or for x86 PV guests to
potentially escalate privileges (XSA-232, bsc#1056280)
- 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).

These non-security issues were fixed:

- bsc#1055695: Fixed restoring updates for HVM guests for ballooned domUs

This update was imported from the SUSE:SLE-12-SP2:Update update project.