---
id: CVE-2025-38337
title: 'jbd2: fix data-race and null-ptr-deref in jbd2_journal_dirty_metadata()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  jbd2: fix data-race and null-ptr-deref in jbd2_journal_dirty_metadata()

  Since handle->h_transaction may be a NULL pointer, so we should change it
  to call is_handle_abo…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 <
    5c1a34ff5b0bfdfd2f9343aa9b08d25df618bac5
  - >-
    Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 <
    ec669e5bf409f16e464bfad75f0ba039a45de29a
  - >-
    Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 <
    43d5e3bb5f1dcd91e30238ea0b59a5f77063f84e
  - >-
    Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 <
    23361b479f2700c00960d3ae9cdc8ededa762d47
  - >-
    Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 <
    2e7c64d7a92c031d016f11c8e8cb05131ab7b75a
  - >-
    Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 <
    f78b38af3540b4875147b7b884ee11a27b3dbf4c
  - >-
    Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 <
    a377996d714afb8d4d5f4906336f78510039da29
  - >-
    Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 <
    af98b0157adf6504fade79b3e6cb260c4ff68e37
  - Linux 4.3
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T20:54:56.222182Z'
published: '2025-07-10'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T21:02:33.964Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-38337'
references:
  - url: 'https://git.kernel.org/stable/c/5c1a34ff5b0bfdfd2f9343aa9b08d25df618bac5'
  - url: 'https://git.kernel.org/stable/c/ec669e5bf409f16e464bfad75f0ba039a45de29a'
  - url: 'https://git.kernel.org/stable/c/43d5e3bb5f1dcd91e30238ea0b59a5f77063f84e'
  - url: 'https://git.kernel.org/stable/c/23361b479f2700c00960d3ae9cdc8ededa762d47'
  - url: 'https://git.kernel.org/stable/c/2e7c64d7a92c031d016f11c8e8cb05131ab7b75a'
  - url: 'https://git.kernel.org/stable/c/f78b38af3540b4875147b7b884ee11a27b3dbf4c'
  - url: 'https://git.kernel.org/stable/c/a377996d714afb8d4d5f4906336f78510039da29'
  - url: 'https://git.kernel.org/stable/c/af98b0157adf6504fade79b3e6cb260c4ff68e37'
tags:
  - cve.org
epss: 0.00196
epssPercentile: 0.09314
ingestedAt: '2026-11-05T22:38:31.957Z'
---

## Overview

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

jbd2: fix data-race and null-ptr-deref in jbd2_journal_dirty_metadata()

Since handle->h_transaction may be a NULL pointer, so we should change it
to call is_handle_aborted(handle) first before dereferencing it.

And the following data-race was reported in my fuzzer:

==================================================================
BUG: KCSAN: data-race in jbd2_journal_dirty_metadata / jbd2_journal_dirty_metadata

write to 0xffff888011024104 of 4 bytes by task 10881 on cpu 1:
 jbd2_journal_dirty_metadata+0x2a5/0x770 fs/jbd2/transaction.c:1556
 __ext4_handle_dirty_metadata+0xe7/0x4b0 fs/ext4/ext4_jbd2.c:358
 ext4_do_update_inode fs/ext4/inode.c:5220 [inline]
 ext4_mark_iloc_dirty+0x32c/0xd50 fs/ext4/inode.c:5869
 __ext4_mark_inode_dirty+0xe1/0x450 fs/ext4/inode.c:6074
 ext4_dirty_inode+0x98/0xc0 fs/ext4/inode.c:6103
....

read to 0xffff888011024104 of 4 bytes by task 10880 on cpu 0:
 jbd2_journal_dirty_metadata+0xf2/0x770 fs/jbd2/transaction.c:1512
 __ext4_handle_dirty_metadata+0xe7/0x4b0 fs/ext4/ext4_jbd2.c:358
 ext4_do_update_inode fs/ext4/inode.c:5220 [inline]
 ext4_mark_iloc_dirty+0x32c/0xd50 fs/ext4/inode.c:5869
 __ext4_mark_inode_dirty+0xe1/0x450 fs/ext4/inode.c:6074
 ext4_dirty_inode+0x98/0xc0 fs/ext4/inode.c:6103
....

value changed: 0x00000000 -> 0x00000001
==================================================================

This issue is caused by missing data-race annotation for jh->b_modified.
Therefore, the missing annotation needs to be added.

## Affected

- `Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 < 5c1a34ff5b0bfdfd2f9343aa9b08d25df618bac5`
- `Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 < ec669e5bf409f16e464bfad75f0ba039a45de29a`
- `Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 < 43d5e3bb5f1dcd91e30238ea0b59a5f77063f84e`
- `Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 < 23361b479f2700c00960d3ae9cdc8ededa762d47`
- `Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 < 2e7c64d7a92c031d016f11c8e8cb05131ab7b75a`
- `Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 < f78b38af3540b4875147b7b884ee11a27b3dbf4c`
- `Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 < a377996d714afb8d4d5f4906336f78510039da29`
- `Linux >= 6e06ae88edae77379bef7c0cb7d3c2dd88676867 < af98b0157adf6504fade79b3e6cb260c4ff68e37`
- `Linux 4.3`

## Remediation

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