Greetings,
And happy new year.
This is hitting all of us soon.
In short : a huge (and long lasting) hardware bug, present in about all
Intel CPUs that have been sold for the last 10 years.
It is not fixable by microcode, and requires ugly patching from the
kernel layer. Other OSes such as Microsoft are concerned as well.
Nice overview of the thing :
https://hothardware.com/news/intel-cpu-bug-kernel-memory-isolation-linux-windows-macos
More detail :
http://pythonsweetness.tumblr.com/post/169166980422/the-mysterious-case-of-the-linux-page-table
Linus' patch :
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5aa90a84589282b87666f92b6c3c917c8080a9bf
Vincent Deffontaines
