---
id: CVE-2025-71135
title: >-
  md/raid5: fix possible null-pointer dereferences in
  raid5_store_group_thread_cnt()
summary: >-
  In the Linux kernel, the following vulnerability has been resolved:


  md/raid5: fix possible null-pointer dereferences in
  raid5_store_group_thread_cnt()


  The variable mddev->private is first assigned to conf and then checked:

    conf = md…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= be19e6e4339d1579d5f2fae8ce4facf9521dbbfc <
    20597b7229aea8b5bc45cd92097640257c7fc33b
  - >-
    Linux >= fa1944bbe6220eb929e2c02e5e8706b908565711 <
    e5abb6af905de6b2fead8a0b3f32ab0b81468a01
  - >-
    Linux >= fa1944bbe6220eb929e2c02e5e8706b908565711 <
    7ad6ef91d8745d04aff9cce7bdbc6320d8e05fe9
  - Linux >= 6.12.4 < 6.12.64
  - Linux 6.13
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T21:14:32.226190Z'
published: '2026-01-14'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T21:23:09.152Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-71135'
references:
  - url: 'https://git.kernel.org/stable/c/20597b7229aea8b5bc45cd92097640257c7fc33b'
  - url: 'https://git.kernel.org/stable/c/e5abb6af905de6b2fead8a0b3f32ab0b81468a01'
  - url: 'https://git.kernel.org/stable/c/7ad6ef91d8745d04aff9cce7bdbc6320d8e05fe9'
tags:
  - cve.org
epss: 0.00176
epssPercentile: 0.0711
ingestedAt: '2026-11-05T22:38:32.051Z'
---

## Overview

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

md/raid5: fix possible null-pointer dereferences in raid5_store_group_thread_cnt()

The variable mddev->private is first assigned to conf and then checked:

  conf = mddev->private;
  if (!conf) ...

If conf is NULL, then mddev->private is also NULL. In this case,
null-pointer dereferences can occur when calling raid5_quiesce():

  raid5_quiesce(mddev, true);
  raid5_quiesce(mddev, false);

since mddev->private is assigned to conf again in raid5_quiesce(), and conf
is dereferenced in several places, for example:

  conf->quiesce = 0;
  wake_up(&conf->wait_for_quiescent);

To fix this issue, the function should unlock mddev and return before
invoking raid5_quiesce() when conf is NULL, following the existing pattern
in raid5_change_consistency_policy().

## Affected

- `Linux >= be19e6e4339d1579d5f2fae8ce4facf9521dbbfc < 20597b7229aea8b5bc45cd92097640257c7fc33b`
- `Linux >= fa1944bbe6220eb929e2c02e5e8706b908565711 < e5abb6af905de6b2fead8a0b3f32ab0b81468a01`
- `Linux >= fa1944bbe6220eb929e2c02e5e8706b908565711 < 7ad6ef91d8745d04aff9cce7bdbc6320d8e05fe9`
- `Linux >= 6.12.4 < 6.12.64`
- `Linux 6.13`

## Remediation

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