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.

Metrics

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Key SSVC decision points have not yet been added.

Affected Vendors & Products

Vendors Products
Linux
  • Linux Kernel

No data.

No data.

References
Link Providers
https://git.kernel.org/stable/c/316b090c2fee964c307a634fecc7df269664b158 cve-icon cve-icon
https://git.kernel.org/stable/c/3a21698ace915a445bce2d0dcfc84b6d2199baf7 cve-icon cve-icon
https://git.kernel.org/stable/c/54506c6335690f4ef1b9f154e34f5a604c72c1ed cve-icon cve-icon
https://git.kernel.org/stable/c/8703940bd30b5ad94408d28d7192db2491cd3592 cve-icon cve-icon
https://git.kernel.org/stable/c/d0ca0df179c4b21e2a6c4a4fb637aa8fa14575cb cve-icon cve-icon
https://git.kernel.org/stable/c/d382d6daf0184490f366562469a5673f65ee2662 cve-icon cve-icon
https://git.kernel.org/stable/c/fbe96bd25423e61273d8831e995260b429d850b6 cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025102404-CVE-2025-40022-cf34@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2025-40022 cve-icon
https://www.cve.org/CVERecord?id=CVE-2025-40022 cve-icon
History

Mon, 27 Oct 2025 22:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Sat, 25 Oct 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Fri, 24 Oct 2025 12:45:00 +0000

Type Values Removed Values Added
Description 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.
Title crypto: af_alg - Fix incorrect boolean values in af_alg_ctx
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-10-24T12:24:57.875Z

Updated: 2025-10-24T12:24:57.875Z

Reserved: 2025-04-16T07:20:57.152Z

Link: CVE-2025-40022

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-10-24T13:15:47.387

Modified: 2025-10-27T13:20:15.637

Link: CVE-2025-40022

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-10-24T00:00:00Z

Links: CVE-2025-40022 - Bugzilla