net: stmmac: fix TSO header length truncation

{
  "id": "b1b5c871ecdbab2e95b39bc650bad8de205965422a2ff2b80e51ec19fca4d086",
  "url": "https://osv.dev/vulnerability/CVE-2026-98288",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net: stmmac: fix TSO header length truncation",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net: stmmac: fix TSO header length truncation stmmac_tso_xmit() stores the protocol header length returned by stmmac_tso_header_size() in a u8. stmmac_tso_valid_packet() admits headers up to 1023 bytes, so a header longer than 255 bytes wraps modulo 256 (486 becomes 230, 256 becomes 0). A TCP over IPv6 socket carrying a few hundred bytes of sticky destination/hop-by-hop options makes skb_tcp_all_headers() exceed 255 while staying below the 1023-byte limit, so such an skb reaches stmmac_tso_xmit(). Widen proto_hdr_len to unsigned int, which is sufficient since the value is bounded by the hardware limit, and adjust the debug print specifier accordingly.",
    "evidence": "osv:CVE-2026-98288",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.2.8",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98288",
      "aliases": [
        "CVE-2026-98288"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "9edfa7dab8112a012b349b7937f5444fdc21e8f9"
                },
                {
                  "fixed": "bcf6013c2b4d732c6e4bf4d0f6ae4a18d63d414b"
                },
                {
                  "fixed": "15989abd74f16f44bf953d056b95f1d2fda9b0cd"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98288.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "4.13.0"
                },
                {
                  "fixed": "7.2.8"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98288.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:29.814015987Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/15989abd74f16f44bf953d056b95f1d2fda9b0cd",
        "https://git.kernel.org/stable/c/bcf6013c2b4d732c6e4bf4d0f6ae4a18d63d414b",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98288.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98288",
        "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/2026/98xxx/CVE-2026-98288.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98288",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 496815,
  "published_at": "2026-10-06T08:45:48.856+00:00"
}