---
id: CVE-2025-40129
title: 'sunrpc: fix null pointer dereference on zero-length checksum'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  sunrpc: fix null pointer dereference on zero-length checksum

  In xdr_stream_decode_opaque_auth(), zero-length checksum.len causes
  checksum.data to be set to NULL. This …
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 0653028e8f1c97fec30710813a001ad8a2ec34f4 <
    81cec07d303186d0d8c623ef8b5ecd3b81e94cf6
  - >-
    Linux >= 0653028e8f1c97fec30710813a001ad8a2ec34f4 <
    affc03d44921f493deaae1d33151e3067a6f9f8f
  - >-
    Linux >= 0653028e8f1c97fec30710813a001ad8a2ec34f4 <
    ab9a70cd2386a0d70c164b0905dd66bc9af52e77
  - >-
    Linux >= 0653028e8f1c97fec30710813a001ad8a2ec34f4 <
    6df164e29bd4e6505c5a2e0e5f1e1f6957a16a42
  - Linux 6.3
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-15T21:57:08.846724Z'
published: '2025-11-12'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:02:38.502Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-40129'
references:
  - url: 'https://git.kernel.org/stable/c/81cec07d303186d0d8c623ef8b5ecd3b81e94cf6'
  - url: 'https://git.kernel.org/stable/c/affc03d44921f493deaae1d33151e3067a6f9f8f'
  - url: 'https://git.kernel.org/stable/c/ab9a70cd2386a0d70c164b0905dd66bc9af52e77'
  - url: 'https://git.kernel.org/stable/c/6df164e29bd4e6505c5a2e0e5f1e1f6957a16a42'
tags:
  - cve.org
epss: 0.00566
epssPercentile: 0.45642
ingestedAt: '2026-10-15T22:48:25.547Z'
---

## Overview

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

sunrpc: fix null pointer dereference on zero-length checksum

In xdr_stream_decode_opaque_auth(), zero-length checksum.len causes
checksum.data to be set to NULL. This triggers a NPD when accessing
checksum.data in gss_krb5_verify_mic_v2(). This patch ensures that
the value of checksum.len is not less than XDR_UNIT.

## Affected

- `Linux >= 0653028e8f1c97fec30710813a001ad8a2ec34f4 < 81cec07d303186d0d8c623ef8b5ecd3b81e94cf6`
- `Linux >= 0653028e8f1c97fec30710813a001ad8a2ec34f4 < affc03d44921f493deaae1d33151e3067a6f9f8f`
- `Linux >= 0653028e8f1c97fec30710813a001ad8a2ec34f4 < ab9a70cd2386a0d70c164b0905dd66bc9af52e77`
- `Linux >= 0653028e8f1c97fec30710813a001ad8a2ec34f4 < 6df164e29bd4e6505c5a2e0e5f1e1f6957a16a42`
- `Linux 6.3`

## Remediation

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