Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw • Hacker News Board

Re: Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw

#91

Post by nomercy400 » Wed, Jan 03, 2018, 3:43 PM UTC

littlestymaar wrote: post #13

Interestingly enough, Intel and AMD market values are affected by this but the cloud provider aren't, which I find surprising.

Do you pay for computing cycles or for a computing instance?

If your cloud provider lowers its performance/efficiency by 30%, isn't it up to its customers to switch? But where to switch too? There's no choice among the big cloud providers. They all use Intel and AMD in varying amounts. As a cloud user you are stuck with Intel or AMD chips. Demand doesn't change, supply is lowered.

Looking at it like this, it is more likely that demand for cloud resources will rise, and as such revenue of the cloud providers will as well.

Re: Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw

#92

Post by Symmetry » Wed, Jan 03, 2018, 3:44 PM UTC

AnIdiotOnTheNet wrote: post #59

Honest question, does the performance hit from this patch actually hit Intel's best processors enough to make them perform worse than AMD's best? I don't keep up on these kinds of metrics, but I'm under the impression that Intel still dominated CPU benchmarks berfore this issue, so if this question is answered in the negative then I doubt it will affect Intel very much.

Intel hasn't been dominating in CPU benchmarks since AMD's new Zen architecture came out. They still have a ~10% lead for gaming but there are as many usecases where AMD is the best choice as there are where Intel is. So if this bug is slowing down Intel but not AMD servers by 10% then suddenly choosing AMD is a no-brainer.

Re: Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw

#93

Post by lmm » Wed, Jan 03, 2018, 3:44 PM UTC

rayiner wrote: post #52

Can someone help me understand why this is such a big deal? This doesn’t seem to be a flaw in the sense of the Pentium FDIV bug where the processor returned incorrect data. It doesn’t even seem to be a bug at all, but a side channel attack that would be almost expected in a processor with speculative execution unless special measures were taken to prevent it. And it doesn’t seem like it can be used for privilege esca…

If you can read kernel (and hypervisor) memory then it seems like a very small step from that to a local root vulnerability - e.g. forge some kind of security token by copying it. There's an embargoed Xen vulnerability that may be related to or combine with this one to mean that anyone running in a VM can break out and access other VMs on the same physical host. That would be a huge issue for cloud providers.

Re: Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw

#94

Post by pcwalton » Wed, Jan 03, 2018, 3:45 PM UTC

twoodfin wrote: post #83

pcwalton wrote: post #67

Earlier quoted context omitted.

Reading secret data out of kernel memory is very bad on cloud environments. Keep in mind that the kernel deals with a lot of cryptography.

Is there anything this bug can give you that you can't get with sudo cat /dev/mem ? I'm having a hard time understanding why this is worse than any other local root escalation bug except for the consequences of the necessary patch. EDIT: I see that /dev/mem is no longer a window on all of physical RAM in a default secure configuration. Is it true that there's no way for root to read kernel memory in a typical Linux i…

You don't need to be root.

> I'm having a hard time understanding why this is worse than any other local root escalation bug except for the consequences of the necessary patch.

It's not, as far as I'm aware. The fact that the patch has perf consequences is why it's such a big deal.

Re: Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw

#95

Post by mtgx » Wed, Jan 03, 2018, 3:46 PM UTC

bla2 wrote: post #68

The bottom of https://danluu.com/cpu-bugs/ suggests that AMD isn't any better, so this is likely just short term.

Since that article came out, AMD built a whole new CPU architecture, with the help of the guy that designed the K8, too.

Re: Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw

#96

Post by mannykannot » Wed, Jan 03, 2018, 3:46 PM UTC

spdy wrote: post #77

zouhair wrote: post #69

Earlier quoted context omitted.

This is typically what happens when you go for a long time without real competition. You get way too comfortable and bad habits start to pile up.

Isn't why this problem even exits the exact opposite? Intel was losing on the mobile market and changed internal testing to iterate faster by cutting corners. Found a quote: "We need to move faster. Validation at Intel is taking much longer than it does for our competition. We need to do whatever we can to reduce those times… we can’t live forever in the shadow of the early 90’s FDIV bug, we need to move on. Our comp…

That is a very interesting perspective, and as far as I know it is correct, though perhaps Intel's situation in the mobile market was exacerbated by complacency?

Re: Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw

#97

Post by dboreham » Wed, Jan 03, 2018, 3:47 PM UTC

rayiner wrote: post #52

Can someone help me understand why this is such a big deal? This doesn’t seem to be a flaw in the sense of the Pentium FDIV bug where the processor returned incorrect data. It doesn’t even seem to be a bug at all, but a side channel attack that would be almost expected in a processor with speculative execution unless special measures were taken to prevent it. And it doesn’t seem like it can be used for privilege esca…

>And it doesn’t seem like it can be used for privilege escalation

Based on all the hoopla around the linux kernel patches the thinking is : yes it can. Or VM escape. Or both.

Re: Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw

#98

Post by chx » Wed, Jan 03, 2018, 3:47 PM UTC

dzink wrote: post #20

Didn’t the Intel CEO just sell half of his shares/options? If he knew about these issues isn’t that illegal?

You can be sure there's a young hotshot with sparkling eyes at SEC who is already typing a letter to Mr. Krzanich politely asking about the circumstances of that sell.

At the same time, noone is doing eight figures transactions which require reporting to the SEC without talking to a lawyer. Right? Right? They really dislike insider trading, it's one of the few things where even rich people can get imprisoned -- and the typical jail sentence has been steadily climbing up for decades now.

Re: Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw

#99

Post by DocSavage » Wed, Jan 03, 2018, 3:48 PM UTC

ashelmire wrote: post #81

dsign wrote: post #19

This is a clusterf /big deal. Beyond the security implications, it means that all companies paying for computing resources will have to pay roughly 30% more overnight on cloud expenses for the same amount of CPU, assuming that they can just scale up their infrastructure. I know that bugs happen and that there was nothing intentional on this one, but at times like this is hard to held at bay the temptation of claiming…

From what I've read, this slowdown only affects syscalls, which, since they aren't usually a huge percentage of processing in the first place, should not have such an effect. You're more likely looking at a few percent at most, which is not going to be enough to make AMD outperform Intel. Let's stop the fear mongering and wait for actual metrics.

Prelim benchmarks show a significant impact (~20%) on Postgresql benchmarks.

Re: Intel Confronts Potential ‘PR Nightmare’ With Reported Chip Flaw

#100

Post by dboreham » Wed, Jan 03, 2018, 3:48 PM UTC

twoodfin wrote: post #83

pcwalton wrote: post #67

Earlier quoted context omitted.

Reading secret data out of kernel memory is very bad on cloud environments. Keep in mind that the kernel deals with a lot of cryptography.

Is there anything this bug can give you that you can't get with sudo cat /dev/mem ? I'm having a hard time understanding why this is worse than any other local root escalation bug except for the consequences of the necessary patch. EDIT: I see that /dev/mem is no longer a window on all of physical RAM in a default secure configuration. Is it true that there's no way for root to read kernel memory in a typical Linux i…

I think the idea is that it is worse because the bug is in the hardware. The OS patches are just a workaround to make the hardware bug unexploitable, and they can lead to a significant performance penalty.