CVE-2026-68480 mitigations for older stable series (was: Re: Linux 6.6.149)

Hi Greg, hi Borislav,

On Thu, Aug 06, 2026 at 07:32:17PM +0200, Greg Kroah-Hartman wrote:
> I'm announcing the release of the 6.6.149 kernel.
> 
> All users of the 6.6 kernel series must upgrade.
> 
> The updated 6.6.y git tree can be found at:
> 	git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git linux-6.6.y
> and can be browsed at the normal kernel.org git web browser:
> 	https://git.kernel.org/?p=linux/kernel/git/stable/linux-stable.git;a=summary

It got mentioned outside of the stable list that the backports of
7e7f81cf6f5c ("x86/bugs: Make Safe-RET robust against interrupt
injection") to address CVE-2026-68480 will not work. So raising the
problem here.

In fact at least they depend on CONFIG_MITIGATION_SRSO, which only was
renamed in a033eec9a06c ("x86/bugs: Rename CONFIG_CPU_SRSO
=> CONFIG_MITIGATION_SRSO") v6.9-rc1, correct?

Borislav, can you have a look for the older backports?

Regards,
Salvatore