FKIE_CVE-2026-80731

Vulnerability from fkie_nvd - Published: 2026-09-03 13:06 - Updated: 2026-10-16 20:18
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: net: remove CAP_SYS_RAWIO zero-padding in dev_validate_header dev_validate_header() reads dev->hard_header_len directly when zero-padding short link layer headers for CAP_SYS_RAWIO holders: if (capable(CAP_SYS_RAWIO)) { memset(ll_header + len, 0, dev->hard_header_len - len); return true; } Packet send paths call dev_validate_header() on skbs whose headroom was allocated from an earlier hard_header_len read. If the device is reconfigured so that dev->hard_header_len increases before validation, the memset writes past the reserved buffer, an out-of-bounds write. This out-of-bounds write is masked in some SOCK_RAW paths today because the same concurrent increase can first make skb_push() exceed the reserved headroom and trigger skb_under_panic(). Remove the zero-padding branch before making those hard_header_len reads consistent, so the snapshot fixes do not turn a loud panic into a silent overwrite. This path is only reached for variable length L2 protocols, where len < hard_header_len but len >= min_header_len. No remaining in-tree variable length L2 protocol implements header_ops->validate, and the CAP_SYS_RAWIO bypass that zero-pads and accepts short headers has no real value beyond allowing testing of intentionally malformed input. Drop the CAP_SYS_RAWIO branch. The remaining reads of dev->hard_header_len in dev_validate_header() are comparisons only and have no memory safety impact.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3b9a324e646d3657a8d9806dfbfe4f3e4066e882
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/53fd7f912c0877647d6a1e1877f5ea8535ee0b4a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/74e035f07f53feca09e2352e77fccb09cad5e208
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8fc9816404166a90ed8d544dc52482fafffb6d9f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/99df6b7a713f96eda206680d100b76e15f9d9b69
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b0f92a5731dc82556a9ae005cc35f71ab136307b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/dbb30dc943a93e083f1e531bfdc6779e57de40d0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fa6d98dd925e72fc028b26a0cbbff9d2f0601ff6
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fc902f52a02298c7432b2334c0c82a2885a1a8b6
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/linux/netdevice.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "53fd7f912c0877647d6a1e1877f5ea8535ee0b4a",
              "status": "affected",
              "version": "b5518429e70cd783b8ca52335456172c1a0589f6",
              "versionType": "git"
            },
            {
              "lessThan": "fa6d98dd925e72fc028b26a0cbbff9d2f0601ff6",
              "status": "affected",
              "version": "2793a23aacbd754dbbb5cb75093deb7e4103bace",
              "versionType": "git"
            },
            {
              "lessThan": "8fc9816404166a90ed8d544dc52482fafffb6d9f",
              "status": "affected",
              "version": "2793a23aacbd754dbbb5cb75093deb7e4103bace",
              "versionType": "git"
            },
            {
              "lessThan": "b0f92a5731dc82556a9ae005cc35f71ab136307b",
              "status": "affected",
              "version": "2793a23aacbd754dbbb5cb75093deb7e4103bace",
              "versionType": "git"
            },
            {
              "lessThan": "99df6b7a713f96eda206680d100b76e15f9d9b69",
              "status": "affected",
              "version": "2793a23aacbd754dbbb5cb75093deb7e4103bace",
              "versionType": "git"
            },
            {
              "lessThan": "74e035f07f53feca09e2352e77fccb09cad5e208",
              "status": "affected",
              "version": "2793a23aacbd754dbbb5cb75093deb7e4103bace",
              "versionType": "git"
            },
            {
              "lessThan": "dbb30dc943a93e083f1e531bfdc6779e57de40d0",
              "status": "affected",
              "version": "2793a23aacbd754dbbb5cb75093deb7e4103bace",
              "versionType": "git"
            },
            {
              "lessThan": "fc902f52a02298c7432b2334c0c82a2885a1a8b6",
              "status": "affected",
              "version": "2793a23aacbd754dbbb5cb75093deb7e4103bace",
              "versionType": "git"
            },
            {
              "lessThan": "3b9a324e646d3657a8d9806dfbfe4f3e4066e882",
              "status": "affected",
              "version": "2793a23aacbd754dbbb5cb75093deb7e4103bace",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "f58a6c08ebdfa978178bbca78c2ba744a2665912",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1df16498dfd0d5a129bdf2982d9a08df73e8923d",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "8b8d278aa4de9335682bbd4a3bb619af015c859e",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6804052fa9d86e9a512c88b24a5debbfc1a490fc",
              "versionType": "git"
            },
            {
              "lessThan": "3.2.81",
              "status": "affected",
              "version": "3.2.80",
              "versionType": "semver"
            },
            {
              "lessThan": "3.17",
              "status": "affected",
              "version": "3.16.36",
              "versionType": "semver"
            },
            {
              "lessThan": "4.2",
              "status": "affected",
              "version": "4.1.28",
              "versionType": "semver"
            },
            {
              "lessThan": "4.5",
              "status": "affected",
              "version": "4.4.8",
              "versionType": "semver"
            },
            {
              "lessThan": "4.6",
              "status": "affected",
              "version": "4.5.2",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/linux/netdevice.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.6"
            },
            {
              "lessThan": "4.6",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "3.2.*",
              "status": "unaffected",
              "version": "3.2.81",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.265",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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",
  "lastModified": "2026-10-16T20:18:09.420",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-80731",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-16T19:21:14.341917Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-09-03T13:06:11.707",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3b9a324e646d3657a8d9806dfbfe4f3e4066e882"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/53fd7f912c0877647d6a1e1877f5ea8535ee0b4a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/74e035f07f53feca09e2352e77fccb09cad5e208"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8fc9816404166a90ed8d544dc52482fafffb6d9f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/99df6b7a713f96eda206680d100b76e15f9d9b69"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b0f92a5731dc82556a9ae005cc35f71ab136307b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/dbb30dc943a93e083f1e531bfdc6779e57de40d0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fa6d98dd925e72fc028b26a0cbbff9d2f0601ff6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fc902f52a02298c7432b2334c0c82a2885a1a8b6"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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