---
id: CVE-2023-53095
title: 'drm/ttm: Fix a NULL pointer dereference'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  drm/ttm: Fix a NULL pointer dereference

  The LRU mechanism may look up a resource in the process of being removed
  from an object. The locking rules here are a bit uncle…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 6a9b028994025f5033f10d1da30b29dfdc713384 <
    9ba1720f6c4a0f13c3f3cb5c28132ee75555d04f
  - >-
    Linux >= 6a9b028994025f5033f10d1da30b29dfdc713384 <
    9d9b1f9f7a72d83ebf173534e76b246349f32374
  - >-
    Linux >= 6a9b028994025f5033f10d1da30b29dfdc713384 <
    9a9a8fe26751334b7739193a94eba741073b8a55
  - Linux 5.19
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T20:17:06.340946Z'
published: '2025-05-02'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:21:00.619Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-53095'
references:
  - url: 'https://git.kernel.org/stable/c/9ba1720f6c4a0f13c3f3cb5c28132ee75555d04f'
  - url: 'https://git.kernel.org/stable/c/9d9b1f9f7a72d83ebf173534e76b246349f32374'
  - url: 'https://git.kernel.org/stable/c/9a9a8fe26751334b7739193a94eba741073b8a55'
tags:
  - cve.org
epss: 0.00199
epssPercentile: 0.09814
ingestedAt: '2026-11-05T22:38:31.768Z'
---

## Overview

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

drm/ttm: Fix a NULL pointer dereference

The LRU mechanism may look up a resource in the process of being removed
from an object. The locking rules here are a bit unclear but it looks
currently like res->bo assignment is protected by the LRU lock, whereas
bo->resource is protected by the object lock, while *clearing* of
bo->resource is also protected by the LRU lock. This means that if
we check that bo->resource points to the LRU resource under the LRU
lock we should be safe.
So perform that check before deciding to swap out a bo. That avoids
dereferencing a NULL bo->resource in ttm_bo_swapout().

## Affected

- `Linux >= 6a9b028994025f5033f10d1da30b29dfdc713384 < 9ba1720f6c4a0f13c3f3cb5c28132ee75555d04f`
- `Linux >= 6a9b028994025f5033f10d1da30b29dfdc713384 < 9d9b1f9f7a72d83ebf173534e76b246349f32374`
- `Linux >= 6a9b028994025f5033f10d1da30b29dfdc713384 < 9a9a8fe26751334b7739193a94eba741073b8a55`
- `Linux 5.19`

## Remediation

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