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

lib/crypto: arm/poly1305: Fix register corruption in no-SIMD contexts

Restore the SIMD usability check that was removed by commit 773426f4771b
("crypto: arm/poly1305 - Add block-only interface").

This safety check is cheap and is well worth eliminating a footgun.
While the Poly1305 functions should not be called when SIMD registers
are unusable, if they are anyway, they should just do the right thing
instead of corrupting random tasks' registers and/or computing incorrect
MACs. Fixing this is also needed for poly1305_kunit to pass.

Just use may_use_simd() instead of the original crypto_simd_usable(),
since poly1305_kunit won't rely on crypto_simd_disabled_for_test.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 15 Sep 2025 13:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: lib/crypto: arm/poly1305: Fix register corruption in no-SIMD contexts Restore the SIMD usability check that was removed by commit 773426f4771b ("crypto: arm/poly1305 - Add block-only interface"). This safety check is cheap and is well worth eliminating a footgun. While the Poly1305 functions should not be called when SIMD registers are unusable, if they are anyway, they should just do the right thing instead of corrupting random tasks' registers and/or computing incorrect MACs. Fixing this is also needed for poly1305_kunit to pass. Just use may_use_simd() instead of the original crypto_simd_usable(), since poly1305_kunit won't rely on crypto_simd_disabled_for_test.
Title lib/crypto: arm/poly1305: Fix register corruption in no-SIMD contexts
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-09-15T12:36:44.792Z

Reserved: 2025-04-16T07:20:57.134Z

Link: CVE-2025-39802

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-09-15T13:15:35.703

Modified: 2025-09-15T13:15:35.703

Link: CVE-2025-39802

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.