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.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

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:

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 : Received

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

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

Link: CVE-2025-40022

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.