The mysterious case of the Linux Page Table Isolation patches • Hacker News Board

Re: The mysterious case of the Linux Page Table Isolation patches

#11

Post by saas_co_de » Mon, Jan 01, 2018, 5:08 PM UTC

tbrownaw wrote: post #2

"Hey, I think I noticed a horrible horrible embargoed security bug. I know, I should do my best to pole holes in the embargo early!"

Embargos do not make you secure. If the bug exists the only safe assumption is that it is already being exploited.

The faster the information gets out the better.

Re: The mysterious case of the Linux Page Table Isolation patches

#12

Post by nobody987 » Mon, Jan 01, 2018, 5:08 PM UTC

AWS had scheduled maintenance requiring reboot of all EC2 instances in December. Maybe this is somehow related.

Re: The mysterious case of the Linux Page Table Isolation patches

#13

Post by saas_co_de » Mon, Jan 01, 2018, 5:11 PM UTC

revelation wrote: post #7

No ones hiding anything, this patchset was developed in the open for many many months. The hysteria and intrigue in this random tumblr blog is completely superfluous. It's a hardware bug anyway. Here is a good hint to when something is not being embargoed: there is a paper and a public demonstration.

It sounds like Intel, Google and Amazon are hiding something. Wouldn't want customers thinking that cloud computing is fundamentally insecure now would we?

Re: The mysterious case of the Linux Page Table Isolation patches

#14

Post by thrill » Mon, Jan 01, 2018, 5:12 PM UTC

jbfoo wrote: post #5

Shouldn't cloud-grade computers be immune to rowhammer (or at least rowhammer should be much less efficient) as they typically use ECC RAM. Switching ECC RAM in a way that also modifies checksum in a deterministic way is (was?) not practical?

The bit flip would be done in a normal fashion - i.e. a command issued that changed the memory location, and hence updates the checksum. The occasional (about one bit flip per Terabyte per hour I think, on average) stray cosmic ray inducing a momentary over-voltage causing the checksum to now disagree would hopefully be within the design's ability to flip back.

Re: The mysterious case of the Linux Page Table Isolation patches

#15

Post by rwmj » Mon, Jan 01, 2018, 5:12 PM UTC

This is probably a better link:

https://lwn.net/SubscriberLink/741878/eb6c9d3913d7cb2b/ (https://news.ycombinator.com/item?id=16001476)

Re: The mysterious case of the Linux Page Table Isolation patches

#16

Post by SimonKinds » Mon, Jan 01, 2018, 5:12 PM UTC

ProAm wrote: post #6

joncrane wrote: post #4

If true, this is pretty huge. As if the AWS "You blew through your budget" emails right around midnight of New Years were only an appetizer. Edit: AWS Spurious Budget Email Barrage: https://www.reddit.com/r/aws/comments/7ndvli/anybody_get_spu...

I missed what happened with AWS? Any details

I'm assuming the person you replied to is referencing emails that AWS sent out on New Year's, stating incorrect forecasted usage.

Some discussion can be found on reddit https://www.reddit.com/r/sysadmin/comments/7ndlk7/aws_anyone...

Re: The mysterious case of the Linux Page Table Isolation patches

#17

Post by cjbprime » Mon, Jan 01, 2018, 5:12 PM UTC

tbrownaw wrote: post #2

"Hey, I think I noticed a horrible horrible embargoed security bug. I know, I should do my best to pole holes in the embargo early!"

They weren't really trying to uncover the exploit such that they can reproduce it. They were trying to learn who the exploit affects and what the impact is. I don't think there's anything wrong with that. If you're an AWS customer who depends on hypervisor isolation for critical security guarantees, it helps you to know that this is threatened and perhaps exploitable.

Please don't buy into the idea that embargoes and coordinated disclosure are sacred. They tend to just reinforce existing power structures, sometimes in an unethical (or at least unfair) way.

Re: The mysterious case of the Linux Page Table Isolation patches

#18

Post by jerrysievert » Mon, Jan 01, 2018, 5:12 PM UTC

ProAm wrote: post #6

joncrane wrote: post #4

If true, this is pretty huge. As if the AWS "You blew through your budget" emails right around midnight of New Years were only an appetizer. Edit: AWS Spurious Budget Email Barrage: https://www.reddit.com/r/aws/comments/7ndvli/anybody_get_spu...

I missed what happened with AWS? Any details

not sure on exact details, but I received one as well, on a free-tier account I had sitting around with an empty dynamodb table that was showing very high projected usage. it was enough that I logged in immediately thinking that account had been hacked.

nope, still empty table, deleted it and went to bed. glad I wasn't the only one who got that.

Re: The mysterious case of the Linux Page Table Isolation patches

#19

Post by cjbprime » Mon, Jan 01, 2018, 5:14 PM UTC

revelation wrote: post #7

No ones hiding anything, this patchset was developed in the open for many many months. The hysteria and intrigue in this random tumblr blog is completely superfluous. It's a hardware bug anyway. Here is a good hint to when something is not being embargoed: there is a paper and a public demonstration.

Will you apologize for saying this if an embargo is lifted? It seems very likely to me that there is an embargo.

Re: The mysterious case of the Linux Page Table Isolation patches

#20

Post by userbinator » Mon, Jan 01, 2018, 5:15 PM UTC

IMHO, with RowHammer, the hardware is broken and it will continue to be broken until users complain enough --- maybe to the point of absolutely refusing to buy --- that the manufacturers and designers stop thinking "works 99.9999999999% of the time" is good enough: https://news.ycombinator.com/item?id=12410274