Re: general protection fault in vmx_vcpu_run (2)

From: Borislav Petkov
Date: Wed Feb 24 2021 - 07:28:17 EST


On Tue, Feb 23, 2021 at 03:17:07PM -0800, syzbot wrote:
> syzbot has bisected this issue to:
>
> commit 167dcfc08b0b1f964ea95d410aa496fd78adf475
> Author: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
> Date: Tue Dec 15 20:56:41 2020 +0000
>
> x86/mm: Increase pgt_buf size for 5-level page tables
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=13fe3ea8d00000
> start commit: a99163e9 Merge tag 'devicetree-for-5.12' of git://git.kern..
> git tree: upstream
> final oops: https://syzkaller.appspot.com/x/report.txt?x=10013ea8d00000

No oops here.

> console output: https://syzkaller.appspot.com/x/log.txt?x=17fe3ea8d00000

Nothing special here too.

> kernel config: https://syzkaller.appspot.com/x/.config?x=49116074dd53b631

Tried this on two boxes, the Intel one doesn't even boot with that
config - and it is pretty standard one - and on the AMD one the
reproducer doesn't trigger anything. It probably won't because the GP
is in vmx_vcpu_run() but since the ioctls were doing something with
IRQCHIP, I thought it is probably vendor-agnostic.

So, all in all, I could use some more info on how you're reproducing and
maybe you could show the oops too.

Thx.

--
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette