Re: [PATCH stable-5.10,5.11,5.12] x86/boot/compressed/64: Check SEV encryption in the 32-bit boot-path

[Joerg Roedel]

On Tue, May 18, 2021 at 01:39:02PM +0200, Joerg Roedel wrote:
> [ Upstream commit fef81c86262879d4b1176ef51a834c15b805ebb9 ]
> 
> Check whether the hypervisor reported the correct C-bit when running
> as an SEV guest. Using a wrong C-bit position could be used to leak
> sensitive data from the guest to the hypervisor.
> 
> Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> Link: https://lkml.kernel.org/r/20210312123824.306-8-joro@xxxxxxxxxx
> ---
>  arch/x86/boot/compressed/head_64.S | 85 ++++++++++++++++++++++++++++++
>  1 file changed, 85 insertions(+)

This is compile-tested now for 5.10, 5.11 and 5.12. With 5.12 I also did
a boot-test using the 32-bit boot-path and verified it still works as
expected.

Regards,

	Joerg