Re: general protection fault in vmx_vcpu_run (2)

From: Dmitry Vyukov
Date: Thu Feb 25 2021 - 09:15:22 EST


On Wed, Feb 24, 2021 at 6:49 PM Borislav Petkov <bp@xxxxxxxxx> wrote:
>
> Hi Dmitry,
>
> On Wed, Feb 24, 2021 at 06:12:57PM +0100, Dmitry Vyukov wrote:
> > Looking at the bisection log, the bisection was distracted by something else.
>
> Meaning the bisection result:
>
> 167dcfc08b0b ("x86/mm: Increase pgt_buf size for 5-level page tables")
>
> is bogus?
>
> > You can always find the original reported issue over the dashboard link:
> > https://syzkaller.appspot.com/bug?extid=42a71c84ef04577f1aef
> > or on lore:
> > https://lore.kernel.org/lkml/0000000000007ff56205ba985b60@xxxxxxxxxx/
>
> Ok, so this looks like this is trying to run kvm ioctls *in* a guest,
> i.e., nested. Right?

Yes, testing happens in VM. But the kernel that crashes is the one
that receives the ioctls.