---
id: CVE-2025-40022
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  crypto: af_alg - Fix incorrect boolean values in af_alg_ctx

  Commit 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in
  af_alg_sendmsg") changed some fields f…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  crypto: af_alg - Fix incorrect boolean values in af_alg_ctx

  Commit 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in
  af_alg_sendmsg") changed some fields f…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 0f28c4adbc4a97437874c9b669fd7958a8c6d6ce <
    3a21698ace915a445bce2d0dcfc84b6d2199baf7
  - >-
    Linux >= e4c1ec11132ec466f7362a95f36a506ce4dc08c9 <
    d382d6daf0184490f366562469a5673f65ee2662
  - >-
    Linux >= 1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8 <
    54506c6335690f4ef1b9f154e34f5a604c72c1ed
  - >-
    Linux >= 7c4491b5644e3a3708f3dbd7591be0a570135b84 <
    8703940bd30b5ad94408d28d7192db2491cd3592
  - >-
    Linux >= 9aee87da5572b3a14075f501752e209801160d3d <
    316b090c2fee964c307a634fecc7df269664b158
  - >-
    Linux >= 45bcf60fe49b37daab1acee57b27211ad1574042 <
    fbe96bd25423e61273d8831e995260b429d850b6
  - >-
    Linux >= 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285 <
    d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb
  - Linux >= 6.1.154 < 6.1.155
  - Linux >= 6.6.108 < 6.6.109
  - Linux >= 6.12.49 < 6.12.50
  - Linux >= 6.16.9 < 6.16.10
published: '2025-10-24'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T02:18:05.020'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-40022'
references:
  - url: 'https://git.kernel.org/stable/c/316b090c2fee964c307a634fecc7df269664b158'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/3a21698ace915a445bce2d0dcfc84b6d2199baf7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/54506c6335690f4ef1b9f154e34f5a604c72c1ed'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8703940bd30b5ad94408d28d7192db2491cd3592'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d382d6daf0184490f366562469a5673f65ee2662'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fbe96bd25423e61273d8831e995260b429d850b6'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-019113.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-082556.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
  - url: 'https://cert-portal.siemens.com/productcert/html/ssa-457936.html'
    label: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
tags:
  - nvd
  - cve.org
epss: 0.00238
epssPercentile: 0.14738
ingestedAt: '2026-09-08T15:33:26.996Z'
---

## Overview

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

crypto: af_alg - Fix incorrect boolean values in af_alg_ctx

Commit 1b34cbbf4f01 ("crypto: af_alg - Disallow concurrent writes in
af_alg_sendmsg") changed some fields from bool to 1-bit bitfields of
type u32.

However, some assignments to these fields, specifically 'more' and
'merge', assign values greater than 1.  These relied on C's implicit
conversion to bool, such that zero becomes false and nonzero becomes
true.

With a 1-bit bitfields of type u32 instead, mod 2 of the value is taken
instead, resulting in 0 being assigned in some cases when 1 was intended.

Fix this by restoring the bool type.

## Remediation

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