FKIE_CVE-2026-63868

Vulnerability from fkie_nvd - Published: 2026-07-19 15:16 - Updated: 2026-07-19 15:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: net: garp: fix unsigned integer underflow in garp_pdu_parse_attr The receive-side GARP attribute parser computes dlen with reversed operands: dlen = sizeof(*ga) - ga->len; ga->len is the on-wire attribute length and includes the GARP attribute header. For normal attributes with data, ga->len is larger than sizeof(*ga), so the subtraction underflows in unsigned arithmetic. The resulting value is later passed to garp_attr_lookup(), whose length argument is u8. After truncation, the parsed data length usually no longer matches the length stored for locally registered attributes, so received Join/Leave events are ignored. This breaks the GARP receive path for common attributes, such as GVRP VLAN registration attributes. Compute the data length as the attribute length minus the header length.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/04e22fefac1af3e32f245e9045382348773b5d59
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/16e408e607a94b646fb14a2a98422c6877ae4b3c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/29f28172afb2ae7b31e9bf3e978396f20b381688
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/74e02121be1dcc0efcd56ebdf0171d6129105659
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/973cf7c433d27f4d9556d0b7c332543be7ed7a6e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a11f1a671b1361f0f1278dc0041374f2730df73f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d4c86ea09ae3e63ee5aa86e941fcc38e0e39874a
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d8dcd14aa886b8effd83022c550669f4f262854b
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/802/garp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "29f28172afb2ae7b31e9bf3e978396f20b381688",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "973cf7c433d27f4d9556d0b7c332543be7ed7a6e",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "d8dcd14aa886b8effd83022c550669f4f262854b",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "74e02121be1dcc0efcd56ebdf0171d6129105659",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "d4c86ea09ae3e63ee5aa86e941fcc38e0e39874a",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "04e22fefac1af3e32f245e9045382348773b5d59",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "a11f1a671b1361f0f1278dc0041374f2730df73f",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            },
            {
              "lessThan": "16e408e607a94b646fb14a2a98422c6877ae4b3c",
              "status": "affected",
              "version": "eca9ebac651f774d8b10fce7c5d173c3c3d3394f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/802/garp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.27"
            },
            {
              "lessThan": "2.6.27",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.259",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.210",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.176",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.143",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.94",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.36",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "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: garp: fix unsigned integer underflow in garp_pdu_parse_attr\n\nThe receive-side GARP attribute parser computes dlen with reversed\noperands:\n\n        dlen = sizeof(*ga) - ga-\u003elen;\n\nga-\u003elen is the on-wire attribute length and includes the GARP attribute\nheader. For normal attributes with data, ga-\u003elen is larger than\nsizeof(*ga), so the subtraction underflows in unsigned arithmetic.\n\nThe resulting value is later passed to garp_attr_lookup(), whose length\nargument is u8. After truncation, the parsed data length usually no\nlonger matches the length stored for locally registered attributes, so\nreceived Join/Leave events are ignored. This breaks the GARP receive path\nfor common attributes, such as GVRP VLAN registration attributes.\n\nCompute the data length as the attribute length minus the header length."
    }
  ],
  "id": "CVE-2026-63868",
  "lastModified": "2026-07-19T15:16:53.740",
  "metrics": {},
  "published": "2026-07-19T15:16:53.740",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/04e22fefac1af3e32f245e9045382348773b5d59"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/16e408e607a94b646fb14a2a98422c6877ae4b3c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/29f28172afb2ae7b31e9bf3e978396f20b381688"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/74e02121be1dcc0efcd56ebdf0171d6129105659"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/973cf7c433d27f4d9556d0b7c332543be7ed7a6e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a11f1a671b1361f0f1278dc0041374f2730df73f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d4c86ea09ae3e63ee5aa86e941fcc38e0e39874a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d8dcd14aa886b8effd83022c550669f4f262854b"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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