---
id: CVE-2026-43337
title: 'drm/amd/display: Fix NULL pointer dereference in dcn401_init_hw()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  drm/amd/display: Fix NULL pointer dereference in dcn401_init_hw()

  dcn401_init_hw() assumes that update_bw_bounding_box() is valid when
  entering the update path. Howeve…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= ca0fb243c3bb53dbbd71d16c76f319bf923ee3d4 <
    fcc51c81cb472eb460310c477460356dc4845ff7
  - >-
    Linux >= ca0fb243c3bb53dbbd71d16c76f319bf923ee3d4 <
    10c13c111d0d7f8e101c742feff264fc98e3f9f7
  - >-
    Linux >= ca0fb243c3bb53dbbd71d16c76f319bf923ee3d4 <
    2d4a6f0702c5211e0be8b688c5fc24f082ec74d6
  - >-
    Linux >= ca0fb243c3bb53dbbd71d16c76f319bf923ee3d4 <
    e927b36ae18b66b49219eaa9f46edc7b4fdbb25e
  - Linux e13689793b9c0e7b5749954e77f5f85e68fe7138
  - Linux >= 6.11.3 < 6.12
  - Linux 6.12
published: '2026-05-08'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:40:39.405Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-43337'
references:
  - url: 'https://git.kernel.org/stable/c/fcc51c81cb472eb460310c477460356dc4845ff7'
  - url: 'https://git.kernel.org/stable/c/10c13c111d0d7f8e101c742feff264fc98e3f9f7'
  - url: 'https://git.kernel.org/stable/c/2d4a6f0702c5211e0be8b688c5fc24f082ec74d6'
  - url: 'https://git.kernel.org/stable/c/e927b36ae18b66b49219eaa9f46edc7b4fdbb25e'
tags:
  - cve.org
epss: 0.0016
epssPercentile: 0.04772
ingestedAt: '2026-10-21T12:48:53.639Z'
---

## Overview

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

drm/amd/display: Fix NULL pointer dereference in dcn401_init_hw()

dcn401_init_hw() assumes that update_bw_bounding_box() is valid when
entering the update path. However, the existing condition:

  ((!fams2_enable && update_bw_bounding_box) || freq_changed)

does not guarantee this, as the freq_changed branch can evaluate to true
independently of the callback pointer.

This can result in calling update_bw_bounding_box() when it is NULL.

Fix this by separating the update condition from the pointer checks and
ensuring the callback, dc->clk_mgr, and bw_params are validated before
use.

Fixes the below:
../dc/hwss/dcn401/dcn401_hwseq.c:367 dcn401_init_hw() error: we previously assumed 'dc->res_pool->funcs->update_bw_bounding_box' could be null (see line 362)

(cherry picked from commit 86117c5ab42f21562fedb0a64bffea3ee5fcd477)

## Affected

- `Linux >= ca0fb243c3bb53dbbd71d16c76f319bf923ee3d4 < fcc51c81cb472eb460310c477460356dc4845ff7`
- `Linux >= ca0fb243c3bb53dbbd71d16c76f319bf923ee3d4 < 10c13c111d0d7f8e101c742feff264fc98e3f9f7`
- `Linux >= ca0fb243c3bb53dbbd71d16c76f319bf923ee3d4 < 2d4a6f0702c5211e0be8b688c5fc24f082ec74d6`
- `Linux >= ca0fb243c3bb53dbbd71d16c76f319bf923ee3d4 < e927b36ae18b66b49219eaa9f46edc7b4fdbb25e`
- `Linux e13689793b9c0e7b5749954e77f5f85e68fe7138`
- `Linux >= 6.11.3 < 6.12`
- `Linux 6.12`

## Remediation

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