Intel Responds to Security Research Findings

Re:Intel Responds to Security Research Findings by mywittyname on Wednesday January 03, 2018 @04:46PM (#16065518)

> Quoting ARM and AMD is really a bit pathetic too, IMHO, especially if it turns out that AMD chips are immune to the flaw.

The official fix for this in the Linux kernel has a comment that literally says to assume all x86 processors suffer from the same issue and will disable KPTI for all x86 processors, including AMD.

There's an AMD-specific patch that I saw floating around that keeps the setting enabled for AMD processors, but I'm not sure if it made it into the mainline.

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Re:Intel Responds to Security Research Findings by betterunix2 on Wednesday January 03, 2018 @04:54PM (#16065605)

https://lkml.org/lkml/2017/12/27/2

It makes reference to the nature of the bug and explains why AMD's chips are not affected (from an AMD engineer).

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Re:Intel Responds to Security Research Findings by mywittyname on Wednesday January 03, 2018 @05:02PM (#16065690)

I was making reference to this [1].

The original fix had a comment that literally said, "/* Assume for now that ALL x86 CPUs are insecure */" They've since added a check to exclude AMD processors.

[1] https://kernel.googlesource.com/pub/scm/linux/kernel/git/tip...

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Re:Intel Responds to Security Research Findings by betterunix2 on Wednesday January 03, 2018 @05:06PM (#16065716)

Same patch I think.

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Re:Intel Responds to Security Research Findings by cesarb on Wednesday January 03, 2018 @05:10PM (#16065756)

That patch would be this git commit: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/...

Not yet on the mainline AFAIK, but I'd guess that whole branch will be merged soon (before the next release candidate).

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Re:Intel Responds to Security Research Findings by qubex on Wednesday January 03, 2018 @04:49PM (#16065554)

I don't know if it's possible to see who contributed that patch (yet), but I’m cynical enough to half-expect that the “assume all x86 processors are insecure” patch might come from an Intel engineer...

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Re:Intel Responds to Security Research Findings by mywittyname on Wednesday January 03, 2018 @04:58PM (#16065652)

I would not be surprised at all, considering the patch I saw for the AMD processors was literally a one-line if statement around the set cpu insecure flag that added a check for AMD processors.

Google is failing me or I'd post a link.

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Re:Intel Responds to Security Research Findings by omeid2 on Wednesday January 03, 2018 @06:42PM (#16066602)

the patch was by Thomas Gleixner[0], who is not an Intel Engineer.

AMD has since pushed a patch to "not enable PTI on AMD processors" [1]

[0] https://patchwork.kernel.org/patch/10138833/

[1] https://patchwork.kernel.org/patch/10142563/

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Re:Intel Responds to Security Research Findings by GalacticDomin8r on Wednesday January 03, 2018 @05:00PM (#16065664)

You might mean this one:

https://lkml.org/lkml/2017/12//27/2

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Re:Intel Responds to Security Research Findings by mywittyname on Wednesday January 03, 2018 @05:06PM (#16065713)

Yeah.

I just found it in their git repo, looks like it was added today. https://kernel.googlesource.com/pub/scm/linux/kernel/git/tip...

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Re:Intel Responds to Security Research Findings by angelsl on Wednesday January 03, 2018 @06:16PM (#16066405)

You mean enable KPTI.

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