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Author Topic: The big Intel (and the others) cpu flaws  (Read 697 times)

pwhodges

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The big Intel (and the others) cpu flaws
« on: 04 Jan 2018, 02:04 »

So Intel processors for ten years have had this hardware flaw that it has now been discovered can be exploited.  We don't have details yet, but it appears to be concerned with kernel memory protection.

https://www.theregister.co.uk/2018/01/02/intel_cpu_design_flaw/

They wanted it kept secret until the patches were out - but there's always someone who feels that the "right to know" trumps common sense. Still, the precise nature of the flaw remains under wraps, so we can't really judge yet just how serious it truly is. The fact that it took ten years for anyone to find it doesn't, of course, mean that exploits are necessarily hard to implement.

The hints we have do suggest (to my knowledge of OS/hardware interaction from past involvement with it) that the patch will have a material hit on performance, so we can expect a big jump in AMD's credibility for a while (indeed, I wonder if maybe they not-quite-leaked it to encourage this before any actually performance measurements appear).
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osaka

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Re: The big Intel (and the others) cpu flaws
« Reply #1 on: 09 Jan 2018, 10:45 »

Randall Munroe has been exceptionally fast with that one.

https://xkcd.com/1938/
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pwhodges

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Re: The big Intel (and the others) cpu flaws
« Reply #2 on: 09 Jan 2018, 11:20 »

Note that my title was incorrect.

(1) there are two distinct flaws (known as Meltdown and Spectre), and
(2) they affect most cpus, not only Intel (though some AMD and ARM cpus don't have both issues).

They are similar, though, as one is concerned with "speculative execution" and the other with "out-of-order" execution, both using the cache behaviour to find the contents of memory they shouldn't be able to.  One enables access to the kernel, and the other access to other processes in the same machine (e.g. even other VMs if they are not fully virtualised).
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"Being human, having your health; that's what's important."  (from: Magical Shopping Arcade Abenobashi )
"As long as we're all living, and as long as we're all having fun, that should do it, right?"  (from: The Eccentric Family )
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