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Google says Rowhammer attacks are gaining range as RAM is getting denser

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Re: Google says Rowhammer attacks are gaining range as RAM is getting denser

#51

Post by rini17 »

gugagore wrote: post #25
creato wrote: post #22

Earlier quoted context omitted.

DRAM manufacturers continue (knowingly at this point) to manufacture faulty products, and we should blame Intel?

I am not familiar with DRAM spec sheets, but are manufacturers specifying that there will be zero errors? Without a specification that says so, I don't think it's necessarily the fault of the manufacturer if they cannot build perfect RAM! Suppose someone builds a car with one these computers in a safety-critical role, and then someone gets injured because of an error that "originated" with the RAM.

They specify timing and when it is followed, RAM should work without fault.

But if there are corner cases like this, they should be added to specs. Most likely it would require memory controller to remember last addresses and insert delays if rowhammer attempt is detected. And/or make CPU microoperation scheduler avoid it. No idea how expensive would that be, surely nontrivial.

Re: Google says Rowhammer attacks are gaining range as RAM is getting denser

#52

Post by rocqua »

gugagore wrote: post #25
creato wrote: post #22

Earlier quoted context omitted.

DRAM manufacturers continue (knowingly at this point) to manufacture faulty products, and we should blame Intel?

I am not familiar with DRAM spec sheets, but are manufacturers specifying that there will be zero errors? Without a specification that says so, I don't think it's necessarily the fault of the manufacturer if they cannot build perfect RAM! Suppose someone builds a car with one these computers in a safety-critical role, and then someone gets injured because of an error that "originated" with the RAM.

If my car's spec doesn't say "the wheels stay on" and then the wheels fall off, the car is still defective.

Re: Google says Rowhammer attacks are gaining range as RAM is getting denser

#53

Post by staticassertion »

GekkePrutser wrote: post #46
staticassertion wrote: post #39

Earlier quoted context omitted.

It's really worth noting that ECC does impact Rowhammer effectiveness, even if it is not enough to prevent the attack 100% of the time.

But as part of this it'll also have a high chance of triggering a system shutdown due to ECC mismatch, right? So in most cases it can't be exploited for things other than DoS.

ECC won't necessarily shut the system down as it can actually repair single bit errors, and mismatches can be monitored for as well. But your point stands - for an attacker to do damage they'll likely end up flipping bits in unintended ways first.

Re: Google says Rowhammer attacks are gaining range as RAM is getting denser

#54

Post by kortilla »

th0ma5 wrote: post #31
r00fus wrote: post #24

Earlier quoted context omitted.

The same way that masks don't prevent COVID.

Right in statistically mostly it does / they do.

No, statistically it’s almost useless to prevent yourself from getting COVID. It’s mainly about reducing your ability to spread it.

That’s why people get mad when you don’t wear a mask even if you “don’t care about getting covid”.

Re: Google says Rowhammer attacks are gaining range as RAM is getting denser

#55

Post by th0ma5 »

kortilla wrote: post #54
th0ma5 wrote: post #31

Earlier quoted context omitted.

Right in statistically mostly it does / they do.

No, statistically it’s almost useless to prevent yourself from getting COVID. It’s mainly about reducing your ability to spread it. That’s why people get mad when you don’t wear a mask even if you “don’t care about getting covid”.

Yes that was a prominent theory at one time and helped a lot of the public adopt masks but it is actually both https://www.npr.org/sections/health-shots/2020/11/11/9339038...

Re: Google says Rowhammer attacks are gaining range as RAM is getting denser

#56

Post by ygjb »

karmicthreat wrote: post #29
atatatat wrote: post #20

Earlier quoted context omitted.

Is there any evidence it's not just a matter of time before there is?

Rowhammer has been known of for over 5 years.

You don't need to have a practical attack for something to be a credible threat that needs to be addressed in a multi-tenant system (like say, cloud providers).

Re: Google says Rowhammer attacks are gaining range as RAM is getting denser

#58

Post by danielheath »

CalChris wrote: post #36
campuscodi wrote: post #10

Earlier quoted context omitted.

Yes, Rowhammer can bypass ECC. Forgot to include this in the article, mainly because there's so much Rowhammer research. See here: https://www.vusec.net/projects/eccploit/

Can Rowhammer bypass ECC and not be detected by an hw_event_mc_err_type ? I don't think so. Why would someone have ECC without a sufficiently sophisticated driver?

> Why would someone have ECC without a sufficiently sophisticated driver?

Have you, personally, tested your servers to make sure the driver correctly handles bit errors? Can't say I have.

Re: Google says Rowhammer attacks are gaining range as RAM is getting denser

#59

Post by ghoward »

vbezhenar wrote: post #47
notriddle wrote: post #9

In other words, blame Intel for trying to pass off ECC as a "Enterprise Feature" instead of the basic necessity that it is.

Do you think many Ryzen PCs use ECC? I doubt that. It's accepted truth among gamers and power users, that ECC is waste of budget. I don't share this position, but if you'd ask on some computer forums, that's what you'll hear. If ECC would be enabled on all Intel CPUs, nothing fundamentally would change, most users would prefer to save 10% on their RAM.

I use it on my Ryzen PC, but I am also running ZFS, and I'm a little paranoid about using my data.

This is one anecdote, though, so it's probably not useful. But people using ECC on Ryzen do exist.

Re: Google says Rowhammer attacks are gaining range as RAM is getting denser

#60

Post by tooltower »

josh2600 wrote: post #27
hypertele-Xii wrote: post #13

Earlier quoted context omitted.

ECC is vulnerable to Rowhammer.

I mean the punchline is: if you heat something up enough then you can get electrons to wiggle. At some level of cell wall thickness, the cost/time/annoyance of triggering a rowhammer exceeds the value of the attack, and other methods become cheaper or more practical. Ultimately, nothing that an attacker has physical access to can be completely secured, we can only raise the cost in terms of time and money to attempt…

We are not talking about physical attacks. Neither are we talking about attacks based purely on heating up the DRAM chips. The topic here is a remote attacker who can target specific words or bits to be flipped.
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