Just as FYI -
latest update of uek5 preview is on https://yum.oracle.com
Oracle Linux 7 Server - Developer preview Unbreakable Enterprise Kernel Release 5
kernel-uek-4.14.20-1.el7uek - The Linux kernel (Update)
This update has a bunch of fixes from us (typically see that with changelog entries containing "orabug" and it pulls in gregkh's stable 4.14.20 tree on top of 4.14.11.
Remember - go check http://yum.oracle.com/whatsnew.html on a regular basis, good source to see what's been updated or added.