5 ms·

That's true, but it leads the odd assumption that the vendor managed to fix N side-channel attacks before release but 0 thereafter, while random individuals fix

That's true, but it leads the odd assumption that the vendor managed to fix N side-channel attacks before release but 0 thereafter, while random individuals fixed M thereafter over a period of years with N >> M. This seems to be much less likely than the conclusion that vendors are not in fact fixing many prior to the release and then stopping "cold turkey" after that. Especially since these attacks seem to cross chip versions, in many cases 6+ generations of chips: if vendors had substantial and increasing efforts on new chip versions they'd also be catching issues that applied to old released chips as well. We don't see that happening.

Panzer04 3y ago
If a bug is not known, most of the incentives to the vendor are to not bother investigating, I suspect. You could spend arbitrary amounts of time looking for these bugs and find nothing. Simpler and easier to offer a bounty or something and fix it then. If no one publicly finds the bug it doesn't matter to the mfg (and it wouldn't surprise me if there's truth to your supposition that they know about the bug but wait to fix until someone reports it - no public backlash so long as the bug is unknown) Fixing bugs prior to release seems easy and free, though, especially since many more eyes would also be on the "new" in progress architecture, and proper hardware mitigations that don't cost a lot of performance can be made.
- skolsuper 3y ago
  What about the incentive to release "the most secure chips on the market", are you discounting that a bit too much? Granted that human nature tends to mean these factors don't have a high enough weight, e.g. it's not the safest airplanes that sell the most, it's the cheapest ones that meet the regulations, and the regulations drive safety improvements, for the most part
  - Panzer04 3y ago
    I guess there's probably some margin in it - if both parties seem about equally vulnerable, there's not much lost. You could expend a lot of effort into security, but the nature of these bugs is still that they are fairly rare, often require pretty significant hurdles, etc. The mfg. could probably spend a lot more money and find a few extra bugs, but who knows if they would have turned into "real" exploits? Remember that this particular bug isn't actually present on the newest chips either - and 12th/13th gen were shipping before Intel was informed of this bug - so it was fixed eventually, probably incidentally as a result of design changes. The unknown factor is how much additional money you'd have to invest to gain additional security, given how esoteric many of these bugs are.
rzwitserloot 3y ago
This. Downfall affects CPUs released almost a decade ago. The argument of 'Intel caught a ton of these and downfall is the one that got away' doesn't add up. Surely Intel would find at least one issue during development of a new chip that has the property that it _also_ affects older chips. They can hardware-fix it before ever releasing their new chip, but unless they just decided to ignore the vulnerability in their older chips, they'd have starte work on a patch or at least on contacting OS vendors. 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.
- AgentOrange1234 3y ago
  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.
  - kragen 3y ago
    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
    - buildbot 3y ago
      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.

Panzer04 3y ago

If a bug is not known, most of the incentives to the vendor are to not bother investigating, I suspect. You could spend arbitrary amounts of time looking for these bugs and find nothing. Simpler and easier to offer a bounty or something and fix it then. If no one publicly finds the bug it doesn't matter to the mfg (and it wouldn't surprise me if there's truth to your supposition that they know about the bug but wait to fix until someone reports it - no public backlash so long as the bug is unknown) Fixing bugs prior to release seems easy and free, though, especially since many more eyes would also be on the "new" in progress architecture, and proper hardware mitigations that don't cost a lot of performance can be made.

skolsuper 3y ago
What about the incentive to release "the most secure chips on the market", are you discounting that a bit too much? Granted that human nature tends to mean these factors don't have a high enough weight, e.g. it's not the safest airplanes that sell the most, it's the cheapest ones that meet the regulations, and the regulations drive safety improvements, for the most part
- Panzer04 3y ago
  I guess there's probably some margin in it - if both parties seem about equally vulnerable, there's not much lost. You could expend a lot of effort into security, but the nature of these bugs is still that they are fairly rare, often require pretty significant hurdles, etc. The mfg. could probably spend a lot more money and find a few extra bugs, but who knows if they would have turned into "real" exploits? Remember that this particular bug isn't actually present on the newest chips either - and 12th/13th gen were shipping before Intel was informed of this bug - so it was fixed eventually, probably incidentally as a result of design changes. The unknown factor is how much additional money you'd have to invest to gain additional security, given how esoteric many of these bugs are.

rzwitserloot 3y ago

This. Downfall affects CPUs released almost a decade ago. The argument of 'Intel caught a ton of these and downfall is the one that got away' doesn't add up. Surely Intel would find at least one issue during development of a new chip that has the property that it _also_ affects older chips. They can hardware-fix it before ever releasing their new chip, but unless they just decided to ignore the vulnerability in their older chips, they'd have starte work on a patch or at least on contacting OS vendors. 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.

AgentOrange1234 3y ago
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.
- kragen 3y ago
  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
  - buildbot 3y ago
    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.