Spotted over on HN:
The mysterious case of the Linux Page Table Isolation patches (archive)
tl;dr: there is presently an embargoed security bug impacting apparently all contemporary CPU architectures that implement virtual memory, requiring hardware changes to fully resolve. Urgent development of a software mitigation is being done in the open and recently landed in the Linux kernel, and a similar mitigation began appearing in NT kernels in November. In the worst case the software fix causes huge slowdowns in typical workloads. There are hints the attack impacts common virtualization environments including Amazon EC2 and Google Compute Engine, and additional hints the exact attack may involve a new variant of Rowhammer.
Turns out 2018 might be more interesting than first thought. So grab some popcorn and keep those systems patched!
(Score: 2) by arcz on Wednesday January 03 2018, @05:11AM (1 child)
(Score: 1, Informative) by Anonymous Coward on Wednesday January 03 2018, @04:06PM
This is the specific issue we're discussing...
It seems they actually discovered a bug not in the x86 prefetch instructions (which could be fixed with microcode) but in Intel's speculative execution.
As to side-channel attacks, you should at least read up on anc [vusec.net] if not all 10 of the papers in the guys PHD thesis - "Software-based Microarchitectural Attacks". [gruss.cc]