CVE-2025-39804

7.8 HIGH
Published: September 15, 2025 Modified: November 24, 2025

Description

In the Linux kernel, the following vulnerability has been resolved: lib/crypto: arm64/poly1305: Fix register corruption in no-SIMD contexts Restore the SIMD usability check that was removed by commit a59e5468a921 ("crypto: arm64/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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://git.kernel.org/stable/c/eec76ea5a7213c48529a46eed1b343e5cee3aaab
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch
https://git.kernel.org/stable/c/ef74efa598b7bbc5c24509f7f56af2806f81c339
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Patch

2 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.8 / 10.0
EPSS (Exploit Probability)
0.0%
4th percentile
Exploitation Status
Not in CISA KEV

Affected Vendors

linux