---
id: CVE-2024-26773
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ext4: avoid allocating blocks from corrupted group in ext4_mb_try_best_found()

  Determine if the group block bitmap is corrupted before using ac_b_ex in
  ext4_mb_try_bes…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ext4: avoid allocating blocks from corrupted group in ext4_mb_try_best_found()

  Determine if the group block bitmap is corrupted before using ac_b_ex in
  ext4_mb_try_bes…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
vendor: linux
product: linux_kernel
affected:
  - linux_kernel < 4.19.308
  - 'linux_kernel >= 4.20, < 5.4.270'
  - 'linux_kernel >= 5.5, < 5.10.211'
  - 'linux_kernel >= 5.11, < 5.15.150'
  - 'linux_kernel >= 5.16, < 6.1.80'
  - 'linux_kernel >= 6.2, < 6.6.19'
  - 'linux_kernel >= 6.7, < 6.7.7'
  - linux_kernel = 6.8
  - debian_linux = 10.0
patched:
  - linux_kernel 6.7.7
published: '2024-04-03'
updated: '2026-08-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-26773'
references:
  - url: 'https://git.kernel.org/stable/c/0184747b552d6b5a14db3b7fcc3b792ce64dedd1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/21f8cfe79f776287459343e9cfa6055af61328ea'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/260fc96283c0f594de18a1b045faf6d8fb42874d'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4530b3660d396a646aad91a787b6ab37cf604b53'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4c21fa60a6f4606f6214a38f50612b17b2f738f5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/927794a02169778c9c2e7b25c768ab3ea8c1dc03'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a2576ae9a35c078e488f2c573e9e6821d651fbbe'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f97e75fa4e12b0aa0224e83fcbda8853ac2adf36'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/0184747b552d6b5a14db3b7fcc3b792ce64dedd1'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/21f8cfe79f776287459343e9cfa6055af61328ea'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/260fc96283c0f594de18a1b045faf6d8fb42874d'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/4530b3660d396a646aad91a787b6ab37cf604b53'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/4c21fa60a6f4606f6214a38f50612b17b2f738f5'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/927794a02169778c9c2e7b25c768ab3ea8c1dc03'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/a2576ae9a35c078e488f2c573e9e6821d651fbbe'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/f97e75fa4e12b0aa0224e83fcbda8853ac2adf36'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00312
epssPercentile: 0.21455
ingestedAt: '2026-08-05T10:46:48.851Z'
---

## Overview

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

ext4: avoid allocating blocks from corrupted group in ext4_mb_try_best_found()

Determine if the group block bitmap is corrupted before using ac_b_ex in
ext4_mb_try_best_found() to avoid allocating blocks from a group with a
corrupted block bitmap in the following concurrency and making the
situation worse.

ext4_mb_regular_allocator
  ext4_lock_group(sb, group)
  ext4_mb_good_group
   // check if the group bbitmap is corrupted
  ext4_mb_complex_scan_group
   // Scan group gets ac_b_ex but doesn't use it
  ext4_unlock_group(sb, group)
                           ext4_mark_group_bitmap_corrupted(group)
                           // The block bitmap was corrupted during
                           // the group unlock gap.
  ext4_mb_try_best_found
    ext4_lock_group(ac->ac_sb, group)
    ext4_mb_use_best_found
      mb_mark_used
      // Allocating blocks in block bitmap corrupted group

## Affected

- `linux_kernel < 4.19.308`
- `linux_kernel >= 4.20, < 5.4.270`
- `linux_kernel >= 5.5, < 5.10.211`
- `linux_kernel >= 5.11, < 5.15.150`
- `linux_kernel >= 5.16, < 6.1.80`
- `linux_kernel >= 6.2, < 6.6.19`
- `linux_kernel >= 6.7, < 6.7.7`
- `linux_kernel = 6.8`
- `debian_linux = 10.0`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.7.7`