On Wed, Oct 20, 2021 at 08:00:28AM -0400, James Bottomley wrote:

On Wed, 2021-10-20 at 08:39 +0200, Greg KH wrote:

quoted

On Wed, Oct 20, 2021 at 06:14:06AM +0000, Dov Murik wrote:

[...]

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quoted

+	help
+	  Copy memory reserved by EFI for Confidential Computing (coco)
+	  injected secrets, if EFI exposes such a table entry.

Why would you want to "copy" secret memory?

This sounds really odd here, it sounds like you are opening up a
security hole.  Are you sure this is the correct text that everyone
on the "COCO" group agrees with?

The way this works is that EFI covers the secret area with a boot time
handoff block, which means it gets destroyed as soon as
ExitBootServices is called as a security measure ... if you do nothing
the secret is shredded.  This means you need to make a copy of it
before that happens if there are secrets that need to live beyond the
EFI boot stub.

Ok, but "copy secrets" does sound really odd, so you all need a much
better description here, and hopefully somewhere else in Documentation/
to describe exactly what this new API is and is to be used for.

Otherwise I read this as "hey a backdoor to read the secrets I wasn't
supposed to be able to see!"

thanks,

greg k-h