Vulnerability 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.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.16, < 6.16.4 |
References
- https://git.kernel.org/stable/c/eec76ea5a7213c48529a46eed1b343e5cee3aaabPatch
- https://git.kernel.org/stable/c/ef74efa598b7bbc5c24509f7f56af2806f81c339Patch
FAQ
What is CVE-2025-39804?
CVE-2025-39804 is a vulnerability with a CVSS score of 7.8 (HIGH). 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 commi...
How severe is CVE-2025-39804?
CVE-2025-39804 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-39804?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.