---
id: CVE-2024-26885
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Fix DEVMAP_HASH overflow check on 32-bit arches

  The devmap code allocates a number hash buckets equal to the next power
  of two of the max_entries value provided w…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  bpf: Fix DEVMAP_HASH overflow check on 32-bit arches

  The devmap code allocates a number hash buckets equal to the next power
  of two of the max_entries value provided w…
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'
cwe:
  - CWE-119
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 5.4, < 5.10.214'
  - 'linux_kernel >= 5.11, < 5.15.153'
  - 'linux_kernel >= 5.16, < 6.1.83'
  - 'linux_kernel >= 6.2, < 6.6.23'
  - 'linux_kernel >= 6.7, < 6.7.11'
  - 'linux_kernel >= 6.8, < 6.8.2'
patched:
  - linux_kernel 6.8.2
published: '2024-04-17'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T01:17:29.170'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2024-26885'
references:
  - url: 'https://git.kernel.org/stable/c/1f5e352b9088211fa5eb4e1639cd365f4f7d2f65'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/22079b3a423382335f47d9ed32114e6c9fe88d7c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/250051acc21f9d4c5c595e4fcb55986ea08c4691'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/281d464a34f540de166cee74b723e97ac2515ec3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4b81a9f92b3676cb74b907a7a209b3d15bd9a7f9'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c826502bed93970f2fd488918a7b8d5f1d30e2e3'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e89386f62ce9a9ab9a94835a9890883c23d9d52c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/edf7990baa48de5097daa9ac02e06cb4c798a737'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/22079b3a423382335f47d9ed32114e6c9fe88d7c'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/225da02acdc97af01b6bc6ce1a3e5362bf01d3fb'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/250051acc21f9d4c5c595e4fcb55986ea08c4691'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/281d464a34f540de166cee74b723e97ac2515ec3'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/c826502bed93970f2fd488918a7b8d5f1d30e2e3'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/e89386f62ce9a9ab9a94835a9890883c23d9d52c'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://git.kernel.org/stable/c/edf7990baa48de5097daa9ac02e06cb4c798a737'
    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://cert-portal.siemens.com/productcert/html/ssa-265688.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.0025
epssPercentile: 0.16262
ingestedAt: '2026-10-15T03:30:12.657Z'
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2024-05-28T19:51:32.926370Z'
---

## Overview

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

bpf: Fix DEVMAP_HASH overflow check on 32-bit arches

The devmap code allocates a number hash buckets equal to the next power
of two of the max_entries value provided when creating the map. When
rounding up to the next power of two, the 32-bit variable storing the
number of buckets can overflow, and the code checks for overflow by
checking if the truncated 32-bit value is equal to 0. However, on 32-bit
arches the rounding up itself can overflow mid-way through, because it
ends up doing a left-shift of 32 bits on an unsigned long value. If the
size of an unsigned long is four bytes, this is undefined behaviour, so
there is no guarantee that we'll end up with a nice and tidy 0-value at
the end.

Syzbot managed to turn this into a crash on arm32 by creating a
DEVMAP_HASH with max_entries > 0x80000000 and then trying to update it.
Fix this by moving the overflow check to before the rounding up
operation.

## Affected

- `linux_kernel >= 5.4, < 5.10.214`
- `linux_kernel >= 5.11, < 5.15.153`
- `linux_kernel >= 5.16, < 6.1.83`
- `linux_kernel >= 6.2, < 6.6.23`
- `linux_kernel >= 6.7, < 6.7.11`
- `linux_kernel >= 6.8, < 6.8.2`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.8.2`