bpf: Require frozen map for calculating map hash

{
  "id": "5c037e673daf8501895cc1366b4dce079c60935d00a3f4aa5ebcd2db0f8ea355",
  "url": "https://osv.dev/vulnerability/CVE-2026-45927",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "bpf: Require frozen map for calculating map hash",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: bpf: Require frozen map for calculating map hash Currently, bpf_map_get_info_by_fd calculates and caches the hash of the map regardless of the map's frozen state. This leads to a TOCTOU bug where userspace can call BPF_OBJ_GET_INFO_BY_FD to cache the hash and then modify the map contents before freezing. Therefore, a trusted loader can be tricked into verifying the stale hash while loading the modified contents. Fix this by returning -EPERM if the map is not frozen when the hash is requested. This ensures the hash is only generated for the final, immutable state of the map.",
    "evidence": "osv:CVE-2026-45927",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.14",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.19.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-45927",
      "aliases": [
        "CVE-2026-45927"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ea2e6467ac36bf3d785defc89e58269b15d182f7"
                },
                {
                  "fixed": "7752d36343862323bbeea4ce3adf0ec2ed86e122"
                },
                {
                  "fixed": "f415e114b58fe02c41191e47f24bdabb438daf72"
                },
                {
                  "fixed": "a2c86aa621c22f2a7e26c654f936d65cfff0aa91"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45927.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.18.0"
                },
                {
                  "fixed": "6.18.14"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "6.19.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45927.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.620509690Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/7752d36343862323bbeea4ce3adf0ec2ed86e122",
        "https://git.kernel.org/stable/c/a2c86aa621c22f2a7e26c654f936d65cfff0aa91",
        "https://git.kernel.org/stable/c/f415e114b58fe02c41191e47f24bdabb438daf72",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45927.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-45927",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45927.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-45927",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 504561,
  "published_at": "2026-05-27T12:17:46.284+00:00"
}