CVE-2026-89751

Updated on 11 Sep 2026

Severity

Awaiting Analysis

Details

Overview

About vulnerability

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

x86/tdx: Fix off-by-one in port I/O handling

handle_in() and handle_out() in arch/x86/coco/tdx/tdx.c use:

u64 mask = GENMASK(BITS_PER_BYTE * size, 0);

GENMASK(h, l) includes bit h. For size=1 (INB), this produces GENMASK(8, 0) = 0x1FF (9 bits) instead of GENMASK(7, 0) = 0xFF (8 bits). The mask is one bit too wide for all I/O sizes.

Fix the mask calculation.

Details

Affected product:
Debian 10 ELS , Debian 11 ELS
Affected packages:
linux @ 5.10.259 (+1 more)

Fixes