CVE-2024-47727

In the Linux kernel, the following vulnerability has been resolved:

x86/tdx: Fix "in-kernel MMIO" check

TDX only supports kernel-initiated MMIO operations. The handle_mmio()

function checks if the #VE exception occurred in the kernel and rejects

the operation if it did not.

However, userspace can deceive the kernel into performing MMIO on its

behalf. For example, if userspace can point a syscall to an MMIO address,

syscall does get_user() or put_user() on it, triggering MMIO #VE. The

kernel will treat the #VE as in-kernel MMIO.

Ensure that the target MMIO address is within the kernel before decoding

instruction.