---
id: CVE-2025-39878
title: 'ceph: fix crash after fscrypt_encrypt_pagecache_blocks() error'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ceph: fix crash after fscrypt_encrypt_pagecache_blocks() error

  The function move_dirty_folio_in_page_array() was created by commit
  ce80b76dd327 ("ceph: introduce ceph_…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: adp
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 0f2b2b7cacf888229cec19126e6791b11fb35f32 <
    4a918f04cf97b2436a8dfe5cb51bb33f8e8831f4
  - >-
    Linux >= ce80b76dd32764cc914975777e058d4fae4f0ea0 <
    dd1616ecbea920d228c56729461ed223cc501425
  - >-
    Linux >= ce80b76dd32764cc914975777e058d4fae4f0ea0 <
    249e0a47cdb46bb9eae65511c569044bd8698d7d
  - Linux 6.15
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-01-14T19:25:07.166494Z'
published: '2025-09-23'
updated: '2026-10-21'
sourceUpdated: '2026-10-21T12:37:31.515Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-39878'
references:
  - url: 'https://git.kernel.org/stable/c/4a918f04cf97b2436a8dfe5cb51bb33f8e8831f4'
  - url: 'https://git.kernel.org/stable/c/dd1616ecbea920d228c56729461ed223cc501425'
  - url: 'https://git.kernel.org/stable/c/249e0a47cdb46bb9eae65511c569044bd8698d7d'
tags:
  - cve.org
epss: 0.00187
epssPercentile: 0.0824
ingestedAt: '2026-10-21T12:48:53.686Z'
---

## Overview

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

ceph: fix crash after fscrypt_encrypt_pagecache_blocks() error

The function move_dirty_folio_in_page_array() was created by commit
ce80b76dd327 ("ceph: introduce ceph_process_folio_batch() method") by
moving code from ceph_writepages_start() to this function.

This new function is supposed to return an error code which is checked
by the caller (now ceph_process_folio_batch()), and on error, the
caller invokes redirty_page_for_writepage() and then breaks from the
loop.

However, the refactoring commit has gone wrong, and it by accident, it
always returns 0 (= success) because it first NULLs the pointer and
then returns PTR_ERR(NULL) which is always 0.  This means errors are
silently ignored, leaving NULL entries in the page array, which may
later crash the kernel.

The simple solution is to call PTR_ERR() before clearing the pointer.

## Affected

- `Linux >= 0f2b2b7cacf888229cec19126e6791b11fb35f32 < 4a918f04cf97b2436a8dfe5cb51bb33f8e8831f4`
- `Linux >= ce80b76dd32764cc914975777e058d4fae4f0ea0 < dd1616ecbea920d228c56729461ed223cc501425`
- `Linux >= ce80b76dd32764cc914975777e058d4fae4f0ea0 < 249e0a47cdb46bb9eae65511c569044bd8698d7d`
- `Linux 6.15`

## Remediation

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