Re:Downfall Attacks
by AgentOrange1234 on Wednesday August 09, 2023 @08:49AM
(#37061864)
FWIW. Spectre/meltdown really caught the hardware development world off guard. Speculative execution was well-trodden ground and we thought it was fine. After these attacks, we had legacy designs that we needed to patch in a hurry, and the performance costs of not speculating were unfathomable. A lot of work went into mitigations like new kinds of barriers. But hardware designs are enormous and there is state lurking absolutely everywhere. It’s just a really hard problem.
dan bernstein had pointed out the risk that speculative execution would lead to side-channel attacks years before, but there's a common pattern where security people point out a risk and then vendors dismiss it as impractical until it's demonstrated in practice
In computer engineering grad school, I mentioned to my PI that there was an upcoming hardware security flaw that I had heard about from … sources… and he quickly guessed it was speculative execution related without knowing anything more. I think people knew it was possibly dangerous, but the performance gains from speculative execution were huge enough nobody in Intel/AMD red-teamed the design basically.
probably incentives are not well-aligned
i mean meltdown didn't exactly crater intel's sales
None of which is easy to do without the public at large figuring out what happend.
Conclusion: That is highly unlikely to have ever happened. Therefore, this isn't survivor bias and it really is bizarre that chip vendors (or, at least, Intel) doesn't look for this stuff or at least didn't find this.