{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "773426f4771bdd82ac5c834bf4c1775315c73a46"
            },
            {
              "fixed": "87bdfba903be7084cb3ee04032b14a81181fe413"
            },
            {
              "fixed": "52c3e242f4d0043186b70d65460ba1767f27494a"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39802.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nlib/crypto: arm/poly1305: Fix register corruption in no-SIMD contexts\n\nRestore the SIMD usability check that was removed by commit 773426f4771b\n(\"crypto: arm/poly1305 - Add block-only interface\").\n\nThis safety check is cheap and is well worth eliminating a footgun.\nWhile the Poly1305 functions should not be called when SIMD registers\nare unusable, if they are anyway, they should just do the right thing\ninstead of corrupting random tasks' registers and/or computing incorrect\nMACs.  Fixing this is also needed for poly1305_kunit to pass.\n\nJust use may_use_simd() instead of the original crypto_simd_usable(),\nsince poly1305_kunit won't rely on crypto_simd_disabled_for_test.",
  "id": "CVE-2025-39802",
  "modified": "2026-04-01T23:09:46.371975360Z",
  "published": "2025-09-15T12:36:44.792Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/52c3e242f4d0043186b70d65460ba1767f27494a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/87bdfba903be7084cb3ee04032b14a81181fe413"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39802.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-39802"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.3",
  "summary": "lib/crypto: arm/poly1305: Fix register corruption in no-SIMD contexts"
}