Re: [PATCH] x86/tdx: Fix data leak in mmio_read()

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.