Google Makes Disclosure About The CPU Vulnerability Affecting Intel / AMD / ARM

We're finally getting actual technical details on the CPU vulnerability leading to the recent race around (K)PTI that when corrected may lead to slower performance in certain situations. Google has revealed they uncovered the issue last year and have now provided some technical bits.

Google says their Project Zero team last year discovered serious flaws in speculative execution that could lead to reading system memory where it shouldn't be authorized. Google was also able to demonstrate an attack where one VM could access the physical memory of the host machine and in turn read memory of other VMs on the same host.

Google reports that this vulnerability not only affects Intel CPUs but also AMD and ARM... Contrary to AMD saying they are not affected by this issue.

Those interested in Google's just-published technical details can find them on the Google Security Blog. Meanwhile, I'm continuing in my benchmarks around the Linux KPTI performance impact, beyond this afternoon's summary.

The issue is now being called "Meltdown and Spectre" with the bug description up at SpectreAttack.com.

Update: AMD has also now posted a response on their limited effect to these CPU security issues.