Re: hunting memory corruption bug in 6.18.x

[Andrew Morton]

On Sun, 18 Oct 2026 18:52:29 +0200 Nikola Ciprich <nikola.ciprich@xxxxxxxxxxx> wrote:

> 
> Hello Sean (and others),
> 
> I think I've finally found the (at least) one missing piece needed to reproduce
> this. At first I wasn't paying much attention to nested virtualization, because
>  we don't use it much (or so I thought), but I was still wondering why
>  why all of this seems to be tied to Windows guests. So I dug into advanced
> Windows security features and found out that newer Windows versions use
> something called Virtualization-Based Security (VBS), which relies on
> exactly that: SVM/VMX, i.e. nested virtualization. (I'm not a Windows guy,
> so excuse my ignorance here.)

Well we initially thought that nested virtualization was not involved.

It it indeed is in the picture then it might have been 55780d8a1dcc
which unknowingly fixed this.

Are you able to test that commit on the 6.18 kernel?