CVE-2026-89751

high

Description

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.

References

https://git.kernel.org/stable/c/c4a22154870813d10aa0b4c734a574c726f9d4b0

https://git.kernel.org/stable/c/bb45f705c4440dd3c689328319b88dd28770bbb8

https://git.kernel.org/stable/c/222b7005e4519f633b4cd666226256abbab46a1a

https://git.kernel.org/stable/c/0f63e656b1c679d32ac595de29d10c03efca6a25

Details

Source: Mitre, NVD

Published: 2026-09-11

Updated: 2026-09-11

Risk Information

CVSS v2

Base Score: 5.6

Vector: CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:C

Severity: Medium

CVSS v3

Base Score: 7.1

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Severity: High

EPSS

EPSS: 0.00168