---
id: CVE-2025-68264
title: 'ext4: refresh inline data size before write operations'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ext4: refresh inline data size before write operations

  The cached ei->i_inline_size can become stale between the initial size
  check and when ext4_update_inline_data()/…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 <
    54ab81ae5f218452e64470cd8a8139bb5880fe2b
  - >-
    Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 <
    43bf001f0fe4e59bba47c897505222f959f4a1cc
  - >-
    Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 <
    89c2c41f0974e530b2d032c3695095aa0559adb1
  - >-
    Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 <
    1687a055a555347b002f406676a1aaae4668f242
  - >-
    Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 <
    210ac60a86a3ad2c76ae60e0dc71c34af6e7ea0b
  - >-
    Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 <
    ca43ea29b4c4d2764aec8a26cffcfb677a871e6e
  - >-
    Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 <
    58df743faf21ceb1880f930aa5dd428e2a5e415d
  - >-
    Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 <
    892e1cf17555735e9d021ab036c36bc7b58b0e3b
  - Linux 3.8
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-06-16T16:56:49.901585Z'
published: '2025-12-16'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T08:43:07.015Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2025-68264'
references:
  - url: 'https://git.kernel.org/stable/c/54ab81ae5f218452e64470cd8a8139bb5880fe2b'
  - url: 'https://git.kernel.org/stable/c/43bf001f0fe4e59bba47c897505222f959f4a1cc'
  - url: 'https://git.kernel.org/stable/c/89c2c41f0974e530b2d032c3695095aa0559adb1'
  - url: 'https://git.kernel.org/stable/c/1687a055a555347b002f406676a1aaae4668f242'
  - url: 'https://git.kernel.org/stable/c/210ac60a86a3ad2c76ae60e0dc71c34af6e7ea0b'
  - url: 'https://git.kernel.org/stable/c/ca43ea29b4c4d2764aec8a26cffcfb677a871e6e'
  - url: 'https://git.kernel.org/stable/c/58df743faf21ceb1880f930aa5dd428e2a5e415d'
  - url: 'https://git.kernel.org/stable/c/892e1cf17555735e9d021ab036c36bc7b58b0e3b'
tags:
  - cve.org
epss: 0.00218
epssPercentile: 0.1249
ingestedAt: '2026-09-08T15:33:26.996Z'
---

## Overview

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

ext4: refresh inline data size before write operations

The cached ei->i_inline_size can become stale between the initial size
check and when ext4_update_inline_data()/ext4_create_inline_data() use
it. Although ext4_get_max_inline_size() reads the correct value at the
time of the check, concurrent xattr operations can modify i_inline_size
before ext4_write_lock_xattr() is acquired.

This causes ext4_update_inline_data() and ext4_create_inline_data() to
work with stale capacity values, leading to a BUG_ON() crash in
ext4_write_inline_data():

  kernel BUG at fs/ext4/inline.c:1331!
  BUG_ON(pos + len > EXT4_I(inode)->i_inline_size);

The race window:
1. ext4_get_max_inline_size() reads i_inline_size = 60 (correct)
2. Size check passes for 50-byte write
3. [Another thread adds xattr, i_inline_size changes to 40]
4. ext4_write_lock_xattr() acquires lock
5. ext4_update_inline_data() uses stale i_inline_size = 60
6. Attempts to write 50 bytes but only 40 bytes actually available
7. BUG_ON() triggers

Fix this by recalculating i_inline_size via ext4_find_inline_data_nolock()
immediately after acquiring xattr_sem. This ensures ext4_update_inline_data()
and ext4_create_inline_data() work with current values that are protected
from concurrent modifications.

This is similar to commit a54c4613dac1 ("ext4: fix race writing to an
inline_data file while its xattrs are changing") which fixed i_inline_off
staleness. This patch addresses the related i_inline_size staleness issue.

## Affected

- `Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 < 54ab81ae5f218452e64470cd8a8139bb5880fe2b`
- `Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 < 43bf001f0fe4e59bba47c897505222f959f4a1cc`
- `Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 < 89c2c41f0974e530b2d032c3695095aa0559adb1`
- `Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 < 1687a055a555347b002f406676a1aaae4668f242`
- `Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 < 210ac60a86a3ad2c76ae60e0dc71c34af6e7ea0b`
- `Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 < ca43ea29b4c4d2764aec8a26cffcfb677a871e6e`
- `Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 < 58df743faf21ceb1880f930aa5dd428e2a5e415d`
- `Linux >= 67cf5b09a46f72e048501b84996f2f77bc42e947 < 892e1cf17555735e9d021ab036c36bc7b58b0e3b`
- `Linux 3.8`

## Remediation

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