Re: [PATCH] x86/tdx: Fix data leak in mmio_read()
From: Kirill A. Shutemov
Date: Mon Aug 26 2024 - 15:44:28 EST
On Mon, Aug 26, 2024 at 09:41:49AM -0700, Dave Hansen wrote:
> On 8/26/24 05:53, Kirill A. Shutemov wrote:
> > The mmio_read() function makes a TDVMCALL to retrieve MMIO data for an
> > address from the VMM.
> >
> > Sean noticed that mmio_read() unintentionally exposes the value of an
> > initialized variable on the stack to the VMM.
> >
> > Do not send the original value of *val to the VMM.
>
> The key to this is that 'val' is only used for the _return_ value, right?
Correct.
--
Kiryl Shutsemau / Kirill A. Shutemov