CVE-2025-40022 Affecting linux-6.1 package, versions <6.1.158-1~deb11u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.06% (19th percentile)

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  • Snyk IDSNYK-DEBIAN11-LINUX61-14114876
  • published26 Nov 2025
  • disclosed24 Oct 2025

Introduced: 24 Oct 2025

CVE-2025-40022  (opens in a new tab)

How to fix?

Upgrade Debian:11 linux-6.1 to version 6.1.158-1~deb11u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.1 package and not the linux-6.1 package as distributed by Debian. See How to fix? for Debian:11 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1