[DGD] Spectre and speculative execution

[Felix A. Croes]

Those who have followed the recent technology news know about Meltdown
and Spectre, two types of bugs having to do with speculative execution.

These are processor-level bugs.  But DGD, and especially Hydra, have
speculative execution at the software level.  Perhaps you have wondered
if they are also vulnerable to the Spectre class of information leakage
bugs?

The answer is that yes, they do.  It is hard to find an example that is
not contrived, but atomic execution and optimistic concurrency can
leak information to other LPC code running on the same server.

That said, LPC code running on the same server has a much wider scope
for side-channel attacks than merely the speculative execution cases.
Measuring executed ticks is a powerful tool in this regard.

Regards,
Felix Croes