{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0ca100ff4df64f5d0f6c1dd5080c3e096786bea6"
            },
            {
              "fixed": "3e04596cba8a86cbff9c3f4bf0a524a3a488773c"
            },
            {
              "fixed": "49875b360c2b83a3c226e189c502e501d83e6445"
            },
            {
              "fixed": "d179a868dd755b0cfcf7582e00943d702b9943b8"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.16.0"
            },
            {
              "fixed": "6.18.23"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.13"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31641.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix RxGK token loading to check bounds\n\nrxrpc_preparse_xdr_yfs_rxgk() reads the raw key length and ticket length\nfrom the XDR token as u32 values and passes each through round_up(x, 4)\nbefore using the rounded value for validation and allocation.  When the raw\nlength is \u003e= 0xfffffffd, round_up() wraps to 0, so the bounds check and\nkzalloc both use 0 while the subsequent memcpy still copies the original\n~4 GiB value, producing a heap buffer overflow reachable from an\nunprivileged add_key() call.\n\nFix this by:\n\n (1) Rejecting raw key lengths above AFSTOKEN_GK_KEY_MAX and raw ticket\n     lengths above AFSTOKEN_GK_TOKEN_MAX before rounding, consistent with\n     the caps that the RxKAD path already enforces via AFSTOKEN_RK_TIX_MAX.\n\n (2) Sizing the flexible-array allocation from the validated raw key\n     length via struct_size_t() instead of the rounded value.\n\n (3) Caching the raw lengths so that the later field assignments and\n     memcpy calls do not re-read from the token, eliminating a class of\n     TOCTOU re-parse.\n\nThe control path (valid token with lengths within bounds) is unaffected.",
  "id": "CVE-2026-31641",
  "modified": "2026-07-08T05:36:16.046864734Z",
  "published": "2026-04-24T14:44:56.204Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3e04596cba8a86cbff9c3f4bf0a524a3a488773c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/49875b360c2b83a3c226e189c502e501d83e6445"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d179a868dd755b0cfcf7582e00943d702b9943b8"
    },
    {
      "type": "WEB",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-31641.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/errata/RHSA-2026:27288"
    },
    {
      "type": "ADVISORY",
      "url": "https://access.redhat.com/security/cve/CVE-2026-31641"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31641.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31641"
    },
    {
      "type": "REPORT",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2461548"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "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": "rxrpc: Fix RxGK token loading to check bounds"
}