{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "3e1c6f35409f9e447bf37f64840f5b65576bfb78"
            },
            {
              "fixed": "0126358df12d6f476f79251d9c398ac5c1b3062d"
            },
            {
              "fixed": "c4be24ef0510c146dca4671effb127e97631534b"
            },
            {
              "fixed": "f9bb6ffa7f5ad0f8ee0f53fc4a10655872ee4a14"
            }
          ],
          "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-2025-39917.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix out-of-bounds dynptr write in bpf_crypto_crypt\n\nStanislav reported that in bpf_crypto_crypt() the destination dynptr's\nsize is not validated to be at least as large as the source dynptr's\nsize before calling into the crypto backend with 'len = src_len'. This\ncan result in an OOB write when the destination is smaller than the\nsource.\n\nConcretely, in mentioned function, psrc and pdst are both linear\nbuffers fetched from each dynptr:\n\n  psrc = __bpf_dynptr_data(src, src_len);\n  [...]\n  pdst = __bpf_dynptr_data_rw(dst, dst_len);\n  [...]\n  err = decrypt ?\n        ctx-\u003etype-\u003edecrypt(ctx-\u003etfm, psrc, pdst, src_len, piv) :\n        ctx-\u003etype-\u003eencrypt(ctx-\u003etfm, psrc, pdst, src_len, piv);\n\nThe crypto backend expects pdst to be large enough with a src_len length\nthat can be written. Add an additional src_len \u003e dst_len check and bail\nout if it's the case. Note that these kfuncs are accessible under root\nprivileges only.",
  "id": "CVE-2025-39917",
  "modified": "2026-04-01T23:10:01.862885954Z",
  "published": "2025-10-01T07:44:39.423Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0126358df12d6f476f79251d9c398ac5c1b3062d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c4be24ef0510c146dca4671effb127e97631534b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f9bb6ffa7f5ad0f8ee0f53fc4a10655872ee4a14"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39917.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-39917"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "bpf: Fix out-of-bounds dynptr write in bpf_crypto_crypt"
}