CVE-2025-40022

/// Technical 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.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References