---
id: CVE-2026-97441
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ata: ahci: fail probe if BAR too small for claimed ports

  When an AHCI controller is disabled in BIOS, its HOST_CAP register may
  contain a bogus value, e.g
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ata: ahci: fail probe if BAR too small for claimed ports

  When an AHCI controller is disabled in BIOS, its HOST_CAP register may
  contain a bogus value, e.g. 0xFFFFFFFF.…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    df262c828b616450eb351349e91c63447551bd01
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    f2e291043c37a896d7f9797e25a356dceb030177
  - >-
    Linux >= 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <
    c4086c6e1af757e1ff26fa2d2926b3ec0195de79
  - Linux < 6.12.111
  - Linux < 6.18.53
  - Linux (all versions)
published: '2026-09-24'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T13:17:27.777'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97441'
references:
  - url: 'https://git.kernel.org/stable/c/c4086c6e1af757e1ff26fa2d2926b3ec0195de79'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/df262c828b616450eb351349e91c63447551bd01'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f2e291043c37a896d7f9797e25a356dceb030177'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-24T16:47:15.878Z'
epss: 0.00166
epssPercentile: 0.05191
---

## Overview

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

ata: ahci: fail probe if BAR too small for claimed ports

When an AHCI controller is disabled in BIOS, its HOST_CAP register may
contain a bogus value, e.g. 0xFFFFFFFF.

Since CAP.NP (Number of Ports) is a zeroes based 5-bit register field,
a value of 0x1f means 32 ports. If CAP.NP claims more ports than can
physically fit within the mapped BAR region, accessing port registers
beyond the BAR boundary causes a kernel panic.

Add validation in ahci_init_one() to check that the BAR size is
sufficient for the number of ports claimed in CAP.NP. The check
calculates the required MMIO size as:

  required_size = 0x100 (global registers) + max_ports * 0x80

If required_size exceeds the actual BAR size, the probe fails with
-ENODEV, preventing the panic and providing a clear error message.

[cassel: commit log]

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.