Hello,
I think we should build and release a new 3.18 kernel for the VirtSIG / Xen users..
It seems upstream 3.18.y tree has a release with the Dirty Cow security fix included, 3.18.44: https://kernel.googlesource.com/pub/scm/linux/kernel/git/sashal/linux-stable...
(also includes a Xen SMAP/PVOPS fix).
Thanks,
-- Pasi