Hi Salvatore,
As I was unfortunately not successful to apply the suggested patch to
the Debian sources, however I since have tried to apply it to 6.4.11
vanilla stable kernel.
That patch has applied fine, and the emulated TPM in KVM is also back
into a working state :-)
So if you back-ported to the Debian kernel, it should hopefully fix
things there too.
If you need me to test a patch for the back-port against the Debian
kernel, and you can provide one, please let me know :-)
Kind Regards,
Martin.
On 17/08/2023 08:38, Salvatore Bonaccorso wrote:
Control: tags -1 + moreinfo upstream
Hi Martin,
On Wed, Aug 16, 2023 at 07:16:58PM +0100, Martin Johnson wrote:
Package: linux-image-amd64
Version: 6.1.0-11-amd64
Update of this recent issue - I might not have specified the package
correctly, sorry for that - its the first bug I tried to report on Debian -
hey Debian really is that good :-)
I found some sort of workaround too, but its far from ideal at present.
To avoid this issue you can set the kernel boot parameter:
spec_rstack_overflow=off
Then the problem no longer exists, obviously with an additional and quite
serious AMD Zen processor security issue.
So the cause is also related to the recent AMD Zen security patch.
The problem seems related to these posts on bugzilla.kernel.org, but is
manifesting in a different way for me:
https://bugzilla.kernel.org/show_bug.cgi?id=217796
and this:
https://bugzilla.kernel.org/show_bug.cgi?id=217796
Did you meant to reference here two different bugzilla enties?
Hope this information is of assistance for anyone who is lucky enough to
find this information :-)
Thanks for providing that. Would it be possible for you to test a
custom kernel built with the following commit applied on top and see
if this resolved the issue you are seeing?
https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?id=ba5ca5e5e6a1d55923e88b4a83da452166f5560e
See
https://kernel-team.pages.debian.net/kernel-handbook/ch-common-tasks.html#id-1.6.6.4
for instructions.
Regards,
Salvatore
