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ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

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Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#91

Post by ct520 »

cfallin wrote: post #88
Fej wrote: post #76

What is the recommended course of action? Stop buying Intel products, and devices which contain them? What about devices with older processors? I'm still running a Sandy Bridge rig and it works fine, except for the side channel vulnerablities. It's probably not going to be patched. I also have a cheaper computer with a Skylake processor, which is newer yet still vulnerable! It's only a matter of time until something…

The stream of critical CPU vulnerabilities starting with Spectre/Meltdown last year are related to speculative execution , not just Intel. (AMD and ARM CPUs are also vulnerable to Spectre, for example.) Intel CPUs are sometimes vulnerable to additional attacks because they speculate in more scenarios than other designs. But fundamentally, as long as multiple different trust domains are sharing one CPU that speculates…

Sounds a lot like something a intel core architect would say ;)

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#92

Post by api »

daeken wrote: post #3

Pandora's box was opened with the public disclosure of Spectre and Meltdown. Security researchers will continue to find new and better ways of attacking the security boundaries in processors, and there's unlikely to be an end to this any time soon. Exciting time to be in security, not such an exciting time to be a potential victim.

It reminds me of when the first buffer overflows were disclosed and they were followed by a massive rash of buffer overflow vulnerabilities that continued for over a decade.

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#93

Post by bin0 »

Fej wrote: post #76

What is the recommended course of action? Stop buying Intel products, and devices which contain them? What about devices with older processors? I'm still running a Sandy Bridge rig and it works fine, except for the side channel vulnerablities. It's probably not going to be patched. I also have a cheaper computer with a Skylake processor, which is newer yet still vulnerable! It's only a matter of time until something…

From what I have heard, these flaws mostly affect Intel because they are the largest CPU manufacturer. They also dominate the datacenter and cloud-compute industries for now, which are by far the highest value targets.

But as an Intel consumer, I am not happy. My understanding is that more stuff can be fixed in microcode, but I suppose a bug could show up which was not practically fixable. If that happened, I would certainly sue or join a class-action lawsuit. Probably the class-action route, because even if I didn't get any thing, I would be just mad enough at Intel to want them to suffer.

Of course, we do have consumer protection agencies; it is possible that they would step if Intel had sold what would effectively be a defective product.

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#94

Post by Fej »

cfallin wrote: post #88
Fej wrote: post #76

What is the recommended course of action? Stop buying Intel products, and devices which contain them? What about devices with older processors? I'm still running a Sandy Bridge rig and it works fine, except for the side channel vulnerablities. It's probably not going to be patched. I also have a cheaper computer with a Skylake processor, which is newer yet still vulnerable! It's only a matter of time until something…

The stream of critical CPU vulnerabilities starting with Spectre/Meltdown last year are related to speculative execution , not just Intel. (AMD and ARM CPUs are also vulnerable to Spectre, for example.) Intel CPUs are sometimes vulnerable to additional attacks because they speculate in more scenarios than other designs. But fundamentally, as long as multiple different trust domains are sharing one CPU that speculates…

Yes, the vulnerabilities are not just Intel, but they're mostly limited to Intel CPUs. Why is AMD less prone to these mistakes? Perhaps there are simply fewer researchers looking into AMD processors?

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#95

Post by [deleted] »

IgorPartola wrote: post #84

So at what point do we start producing CPUs specifically aimed at running a kernel/userland? Why don't we have a CPU architecture where a master core is dedicated to running the kernel and a bunch of other cores run userland programs? I am genuinely curious. I understand that x86 is now the dominant platform in cloud computing. But it's not like virtualization needs to be infinitely nested, right? Why not have the ho…

[deleted]

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#96

Post by jupp0r »

Fej wrote: post #94
cfallin wrote: post #88

Earlier quoted context omitted.

The stream of critical CPU vulnerabilities starting with Spectre/Meltdown last year are related to speculative execution , not just Intel. (AMD and ARM CPUs are also vulnerable to Spectre, for example.) Intel CPUs are sometimes vulnerable to additional attacks because they speculate in more scenarios than other designs. But fundamentally, as long as multiple different trust domains are sharing one CPU that speculates…

Yes, the vulnerabilities are not just Intel, but they're mostly limited to Intel CPUs. Why is AMD less prone to these mistakes? Perhaps there are simply fewer researchers looking into AMD processors?

The focus is on Intel partially because it's the most valuable target, so we might be looking at selection bias.

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#97

Post by Symmetry »

cfallin wrote: post #88
Fej wrote: post #76

What is the recommended course of action? Stop buying Intel products, and devices which contain them? What about devices with older processors? I'm still running a Sandy Bridge rig and it works fine, except for the side channel vulnerablities. It's probably not going to be patched. I also have a cheaper computer with a Skylake processor, which is newer yet still vulnerable! It's only a matter of time until something…

The stream of critical CPU vulnerabilities starting with Spectre/Meltdown last year are related to speculative execution , not just Intel. (AMD and ARM CPUs are also vulnerable to Spectre, for example.) Intel CPUs are sometimes vulnerable to additional attacks because they speculate in more scenarios than other designs. But fundamentally, as long as multiple different trust domains are sharing one CPU that speculates…

I think there's quite a big difference between leaking information between security contexts (Meltdown) and leaking within a security context (Spectre). The later is a problem but it's not a the same magnitude of failure as the former is.

Also, no need for older SoCs. High end ARM chips have both in-order and out-of-order cores but the cheaper ones have in-order ones only. A Snapdragon 450 is pretty modern and doesn't speculate deeply enough to be vulnerable to Spectre.

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#98

Post by jupp0r »

justryry wrote: post #85

Do cloud providers commonly float cores between VMs? I could see instances like the AWS T family (burstable) sharing, but I had always assumed that most instance types don't over-provision CPU. If that's the case, my CPUs are likely pinned to my VM. I could still have evil userland apps spying on my own VM, but I would not expect this to allow other VMs to spy on mine.

Sharing CPUs is not the point, as long as you are sharing physical memory with other tenants, you are vulnerable (although exploits are much harder when attackers have to cross privilege boundaries).

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#99

Post by coliveira »

Fej wrote: post #94
cfallin wrote: post #88

Earlier quoted context omitted.

The stream of critical CPU vulnerabilities starting with Spectre/Meltdown last year are related to speculative execution , not just Intel. (AMD and ARM CPUs are also vulnerable to Spectre, for example.) Intel CPUs are sometimes vulnerable to additional attacks because they speculate in more scenarios than other designs. But fundamentally, as long as multiple different trust domains are sharing one CPU that speculates…

Yes, the vulnerabilities are not just Intel, but they're mostly limited to Intel CPUs. Why is AMD less prone to these mistakes? Perhaps there are simply fewer researchers looking into AMD processors?

This happens only because Intel went much further than AMD and other companies in exploring these effects. If other companies used speculative execution as much as Intel, the result would be the same. It is not a flaw of implementation, it is a flaw of basic design.

Re: ZombieLoad: Cross Privilege-Boundary Data Leakage on Intel CPUs

#100

Post by founderling »

IgorPartola wrote: post #84

So at what point do we start producing CPUs specifically aimed at running a kernel/userland? Why don't we have a CPU architecture where a master core is dedicated to running the kernel and a bunch of other cores run userland programs? I am genuinely curious. I understand that x86 is now the dominant platform in cloud computing. But it's not like virtualization needs to be infinitely nested, right? Why not have the ho…

You cannot give each VM their own core. The business model of the cloud is that multiple VMs with virtual cores run on a single real core.
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