{
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      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
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          "type": "ECOSYSTEM"
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          "type": "ECOSYSTEM"
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  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80731.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: remove CAP_SYS_RAWIO zero-padding in dev_validate_header\n\ndev_validate_header() reads dev-\u003ehard_header_len directly when\nzero-padding short link layer headers for CAP_SYS_RAWIO holders:\n\n    if (capable(CAP_SYS_RAWIO)) {\n        memset(ll_header + len, 0, dev-\u003ehard_header_len - len);\n        return true;\n    }\n\nPacket send paths call dev_validate_header() on skbs whose headroom was\nallocated from an earlier hard_header_len read. If the device is\nreconfigured so that dev-\u003ehard_header_len increases before validation,\nthe memset writes past the reserved buffer, an out-of-bounds write.\n\nThis out-of-bounds write is masked in some SOCK_RAW paths today because\nthe same concurrent increase can first make skb_push() exceed the\nreserved headroom and trigger skb_under_panic(). Remove the zero-padding\nbranch before making those hard_header_len reads consistent, so the\nsnapshot fixes do not turn a loud panic into a silent overwrite.\n\nThis path is only reached for variable length L2 protocols, where\nlen \u003c hard_header_len but len \u003e= min_header_len. No remaining in-tree\nvariable length L2 protocol implements header_ops-\u003evalidate, and the\nCAP_SYS_RAWIO bypass that zero-pads and accepts short headers has no\nreal value beyond allowing testing of intentionally malformed input.\n\nDrop the CAP_SYS_RAWIO branch. The remaining reads of\ndev-\u003ehard_header_len in dev_validate_header() are comparisons only and\nhave no memory safety impact.",
  "id": "CVE-2026-80731",
  "modified": "2026-09-05T03:30:49.286224223Z",
  "published": "2026-09-03T08:21:48.924Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3b9a324e646d3657a8d9806dfbfe4f3e4066e882"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/53fd7f912c0877647d6a1e1877f5ea8535ee0b4a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/74e035f07f53feca09e2352e77fccb09cad5e208"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8fc9816404166a90ed8d544dc52482fafffb6d9f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/99df6b7a713f96eda206680d100b76e15f9d9b69"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b0f92a5731dc82556a9ae005cc35f71ab136307b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dbb30dc943a93e083f1e531bfdc6779e57de40d0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fa6d98dd925e72fc028b26a0cbbff9d2f0601ff6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fc902f52a02298c7432b2334c0c82a2885a1a8b6"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80731.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-80731"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "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": "net: remove CAP_SYS_RAWIO zero-padding in dev_validate_header"
}