From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris.Paterson2@renesas.com (Chris Paterson) Date: Tue, 16 Jan 2018 08:01:44 +0000 Subject: [cip-dev] Meltdown and Spectre in CIP In-Reply-To: <1515593818.12097.10.camel@codethink.co.uk> References: <1515593818.12097.10.camel@codethink.co.uk> Message-ID: To: cip-dev@lists.cip-project.org List-Id: cip-dev.lists.cip-project.org Hello Ben, Thank you for the summary. > From: cip-dev-bounces at lists.cip-project.org [mailto:cip-dev- > bounces at lists.cip-project.org] On Behalf Of Ben Hutchings > Sent: 10 January 2018 14:17 > > I expect that everyone's heard about the above security issues and I > understand there have been questions about how and when these will be > addressed in CIP. > > My thinking is that for these are *not* serious issues for embedded systems, > though they do weaken the "defence in depth" that is normally provided by > memory protection and user privilege separation.??We do need to get fixes > out, but not urgently. > > (When we discussed kernel configurations and maintainability, there was > consensus that no-one using KVM was relying on it being secure against > malicious guests - the guests were trusted.) > > This is the current status of mitigations for these issues, as I understand it: > > Meltdown: > - arm 32-bit: Not affected? (ARM reports that only the Cortex-A75 is > affected, but I haven't seen information from other architecture > licensees.) ARM also lists that meltdown subvariant '3a' affects some arm 32-bit processors [1], but say that "In general, it is not believed that software mitigations for this issue are necessary". The whitepaper ARM link to [2] implies that ARM don't think this is an issue worth worrying about as the information that can be obtained from the system registers is "not material". Have you heard/seen anything to contradict this statement? > - x86 32-bit: Not fixed, no plans to fix. There are two affected > configurations that I'm aware of: Siemens' i386-rt and iot2000. > I doubt that the Quark processor in iot2000 is affected. > - x86 64-bit: Fully mitigated in mainline and 4.4-stable. > > Spectre: will be mitigated in mainline, but still under discussion. > Based on what I've seen, I expect that it will be possible to backport most of > these to 4.4. Will you be keeping an eye on Spectre patches on behalf of CIP as part of your maintainer role? I guess you may be in the loop a bit more than the rest of us? [1] https://developer.arm.com/support/security-update [2] https://developer.arm.com/support/security-update/download-the-whitepaper Kind regards, Chris