geneve: validate inner network offset in geneve_gro_complete()

{
  "id": "2969659d1c626b28cc2b26d170da407ca764264d80c4a3cdc3da1b29acdf48ec",
  "url": "https://osv.dev/vulnerability/CVE-2026-72407",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "geneve: validate inner network offset in geneve_gro_complete()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: geneve: validate inner network offset in geneve_gro_complete() Even with both paths gated on gs->gro_hint, geneve_gro_complete() re-derives the inner dispatch type and length from the packet and the current gs->gro_hint, independently of geneve_gro_receive(). The two can disagree if gs->gro_hint flips under a concurrent geneve_quiesce()/ geneve_unquiesce() (sk_user_data is NULL across a synchronize_net()), or if the re-read option bytes differ from the ones receive parsed. geneve_gro_receive() already records the inner network header position in NAPI_GRO_CB()->inner_network_offset. Have geneve_gro_complete() compute the offset it is about to dispatch at, adding ETH_HLEN in the ETH_P_TEB case where eth_gro_complete() steps over the inner MAC header, and bail out if it lands past inner_network_offset. Use a lower bound rather than exact equality: between gh_len and the inner L3 header, geneve_gro_receive() may also have pulled an inner VLAN tag (vlan_gro_receive() advances the recorded offset past it), which only moves inner_network_offset further out. A valid frame therefore always satisfies inner_nh <= inner_network_offset, while a gh_len inflated by a hint gro_receive() did not honour dispatches past the validated inner header, i.e. the out-of-bounds completion. Only the latter is rejected.",
    "evidence": "osv:CVE-2026-72407",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.1.5",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-72407",
      "aliases": [
        "CVE-2026-72407"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "fd0dd796576e1a560e1441e665810129f0a82be0"
                },
                {
                  "fixed": "e2087447f562692ff0cd08a0554d8d4ad083aa5c"
                },
                {
                  "fixed": "cbb0d30a1ad6fc9439b1dc9b4f5a7a9140d3b11f"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72407.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "7.0.0"
                },
                {
                  "fixed": "7.1.5"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-72407.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:52.739560538Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/cbb0d30a1ad6fc9439b1dc9b4f5a7a9140d3b11f",
        "https://git.kernel.org/stable/c/e2087447f562692ff0cd08a0554d8d4ad083aa5c",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72407.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-72407",
        "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/2026/72xxx/CVE-2026-72407.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-72407",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 521486,
  "published_at": "2026-08-15T05:56:30.847+00:00"
}