CVE-2025-39804
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-09-15

Last updated on: 2025-11-24

Assigner: kernel.org

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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Meta Information
Published
2025-09-15
Last Modified
2025-11-24
Generated
2026-05-27
AI Q&A
2025-09-15
EPSS Evaluated
2026-05-25
NVD
CVE-2025-39804
Affected Vendors & Products
Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
Helpful Resources
Exploitability
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KEV
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CWE ID Description
CWE-NVD-CWE-noinfo
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability in the Linux kernel's arm64 Poly1305 cryptographic implementation involves register corruption in no-SIMD (Single Instruction, Multiple Data) contexts. A safety check that ensures SIMD registers are usable was removed, which could lead to Poly1305 functions corrupting random tasks' registers or computing incorrect Message Authentication Codes (MACs) when SIMD registers are not usable. The fix restores this safety check to prevent such corruption and incorrect computations.


How can this vulnerability impact me? :

If exploited, this vulnerability could cause corruption of registers belonging to random tasks, potentially leading to system instability or incorrect cryptographic computations (incorrect MACs). This could undermine the integrity of cryptographic operations relying on Poly1305, possibly affecting data security and system reliability.


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