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MDS and other speculation issues

cip-dev Ben Hutchings 2 participants 3 messages May 15, 2019 – May 16, 2019

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Ben Hutchings

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As with the earlier speculation vulnerabilities, I don't believe that MDS should be a particularly severe issue for CIP-based systems.

Nevertheless, I have prepared a backport of the mitigations for MDS (and some changes to the mitigations for other speculation issues) for 4.4. This was included in 4.4.180-rc1, which is out for review now. I did not have the chance to test this thoroughly, so review and testing are needed.

Ben.

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Ben Hutchings, Software Developer                ?        Codethink Ltd
https://www.codethink.co.uk/                 Dale House, 35 Dale Street
                                     Manchester, M1 2HF, United Kingdom
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Hi Ben,

Quoted 8 lines

-----Original Message-----
From: cip-dev-bounces at lists.cip-project.org [mailto:cip-dev-bounces at lists.cip-project.org] On Behalf Of Ben Hutchings
Sent: Wednesday, May 15, 2019 8:34 PM
To: cip-dev at lists.cip-project.org
Subject: [cip-dev] MDS and other speculation issues

Quoted 8 lines

As with the earlier speculation vulnerabilities, I don't believe that MDS should be a particularly severe issue for CIP-based systems.

Nevertheless, I have prepared a backport of the mitigations for MDS (and some changes to the mitigations for other speculation issues) for 4.4. This was included in 4.4.180-rc1, which is out for review now. I did not have the chance to test this thoroughly, so review and testing are needed.

Thank you for your work and information.
I'm just looking into a test tool for this issue, but please let me know what you already know.

There is a spectre-meltdown-checker, but we can not do a detailed test with this.
https://github.com/speed47/spectre-meltdown-checker/

Quoted 3 lines

Ben.

Best regards,
Nobuhirio

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#2 lore raw
Quoted 19 lines · On Thu, 2019-05-16 at 00:44 +0000, nobuhiro1.iwamatsu at toshiba.co.jp wrote:

Hi Ben,

Quoted 8 lines

-----Original Message-----
From: cip-dev-bounces at lists.cip-project.org

Quoted 1 line
Quoted 1 line

[mailto:cip-dev-bounces at lists.cip-project.org] On Behalf Of Ben

Hutchings
Sent: Wednesday, May 15, 2019 8:34 PM
To: cip-dev at lists.cip-project.org
Subject: [cip-dev] MDS and other speculation issues

Quoted 8 lines

As with the earlier speculation vulnerabilities, I don't believe that MDS should be a particularly severe issue for CIP-based systems.

Nevertheless, I have prepared a backport of the mitigations for MDS (and some changes to the mitigations for other speculation issues) for 4.4. This was included in 4.4.180-rc1, which is out for review now.??I did not have the chance to test this thoroughly, so review and testing are needed.

Quoted 3 lines

Thank you for your work and information.
I'm just looking into a test tool for this issue, but please let me know what you already know.

There is proof-of-concept exploit code, but it's not yet public, so far as I know. Nor do I have a copy.

Quoted 2 lines

There is a spectre-meltdown-checker, but we can not do a detailed test with this.
https://github.com/speed47/spectre-meltdown-checker/

That uses kernel interfaces to identify the affected CPUs and any mitigations that are enabled. However, it does not test whether the mitigation is actually effective, so it won't detect incomplete or incorrect backports.

Ben.

Signature · 3 lines
Ben Hutchings, Software Developer                ?        Codethink Ltd
https://www.codethink.co.uk/                 Dale House, 35 Dale Street
                                     Manchester, M1 2HF, United Kingdom