---
id: CVE-2022-49879
title: 'ext4: fix BUG_ON() when directory entry has invalid rec_len'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ext4: fix BUG_ON() when directory entry has invalid rec_len

  The rec_len field in the directory entry has to be a multiple of 4.  A
  corrupted filesystem image can be us…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 3d0518f4758eca4339e75e5b9dbb7e06a5ce08b4 <
    2fa24d0274fbf913b56ee31f15bc01168669d909
  - >-
    Linux >= 3d0518f4758eca4339e75e5b9dbb7e06a5ce08b4 <
    156451a67b93986fb07c274ef6995ff40766c5ad
  - >-
    Linux >= 3d0518f4758eca4339e75e5b9dbb7e06a5ce08b4 <
    999cff2b6ce3b45c08abf793bf55534777421327
  - >-
    Linux >= 3d0518f4758eca4339e75e5b9dbb7e06a5ce08b4 <
    ce1ee2c8827fb6493e91acbd50f664cf2a972c3d
  - >-
    Linux >= 3d0518f4758eca4339e75e5b9dbb7e06a5ce08b4 <
    17a0bc9bd697f75cfdf9b378d5eb2d7409c91340
  - Linux 2.6.30
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T19:51:06.646371Z'
published: '2025-05-01'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:00:10.635Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2022-49879'
references:
  - url: 'https://git.kernel.org/stable/c/2fa24d0274fbf913b56ee31f15bc01168669d909'
  - url: 'https://git.kernel.org/stable/c/156451a67b93986fb07c274ef6995ff40766c5ad'
  - url: 'https://git.kernel.org/stable/c/999cff2b6ce3b45c08abf793bf55534777421327'
  - url: 'https://git.kernel.org/stable/c/ce1ee2c8827fb6493e91acbd50f664cf2a972c3d'
  - url: 'https://git.kernel.org/stable/c/17a0bc9bd697f75cfdf9b378d5eb2d7409c91340'
tags:
  - cve.org
epss: 0.00218
epssPercentile: 0.12384
ingestedAt: '2026-11-05T22:38:31.622Z'
---

## Overview

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

ext4: fix BUG_ON() when directory entry has invalid rec_len

The rec_len field in the directory entry has to be a multiple of 4.  A
corrupted filesystem image can be used to hit a BUG() in
ext4_rec_len_to_disk(), called from make_indexed_dir().

 ------------[ cut here ]------------
 kernel BUG at fs/ext4/ext4.h:2413!
 ...
 RIP: 0010:make_indexed_dir+0x53f/0x5f0
 ...
 Call Trace:
  <TASK>
  ? add_dirent_to_buf+0x1b2/0x200
  ext4_add_entry+0x36e/0x480
  ext4_add_nondir+0x2b/0xc0
  ext4_create+0x163/0x200
  path_openat+0x635/0xe90
  do_filp_open+0xb4/0x160
  ? __create_object.isra.0+0x1de/0x3b0
  ? _raw_spin_unlock+0x12/0x30
  do_sys_openat2+0x91/0x150
  __x64_sys_open+0x6c/0xa0
  do_syscall_64+0x3c/0x80
  entry_SYSCALL_64_after_hwframe+0x46/0xb0

The fix simply adds a call to ext4_check_dir_entry() to validate the
directory entry, returning -EFSCORRUPTED if the entry is invalid.

## Affected

- `Linux >= 3d0518f4758eca4339e75e5b9dbb7e06a5ce08b4 < 2fa24d0274fbf913b56ee31f15bc01168669d909`
- `Linux >= 3d0518f4758eca4339e75e5b9dbb7e06a5ce08b4 < 156451a67b93986fb07c274ef6995ff40766c5ad`
- `Linux >= 3d0518f4758eca4339e75e5b9dbb7e06a5ce08b4 < 999cff2b6ce3b45c08abf793bf55534777421327`
- `Linux >= 3d0518f4758eca4339e75e5b9dbb7e06a5ce08b4 < ce1ee2c8827fb6493e91acbd50f664cf2a972c3d`
- `Linux >= 3d0518f4758eca4339e75e5b9dbb7e06a5ce08b4 < 17a0bc9bd697f75cfdf9b378d5eb2d7409c91340`
- `Linux 2.6.30`

## Remediation

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