{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-80876",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-80876",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-09-04T16:48:50.082Z",
    "updatedAt": "2026-09-04T16:48:50.082Z",
    "importedAt": "2026-10-24T01:58:30.346Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "ring-buffer: Fix event length with forced 8-byte alignment",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nring-buffer: Fix event length with forced 8-byte alignment\n\nWhen RB_FORCE_8BYTE_ALIGNMENT is true, rb_calculate_event_length()\nreserves the space of event->array[0] for placing the data length and\nrb_update_event() stores the data length in event->array[0]\naccordingly. As a result the whole event length will add extra 4 bytes\nfor sizeof(event.array[0]) unconditionally.\n\nBut ring_buffer_event_length() only subtracts the\nsizeof(event->array[0]) for events larger than RB_MAX_SMALL_DATA +\nsizeof(event->array[0]). As a result, small events on architectures\nwith RB_FORCE_8BYTE_ALIGNMENT=true report a data length that is 4\nbytes larger than expected.\n\nTo fix it, add the RB_FORCE_8BYTE_ALIGNMENT as a condition to subtract\nthe size of that length field whenever RB_FORCE_8BYTE_ALIGNMENT is\ntrue.\n\nThis issue is observed in a riscv64 kernel with\nCONFIG_HAVE_64BIT_ALIGNED_ACCESS set to y, when we run ftrace selftest\ntrace_marker_raw.tc, we get the weird log: for cases where the id is\n1..100, the number of data field is 8*N, but once id exceeds 100, the\nnumber of data field becomes 8*N+4:\n # 1 buf: 58 00 00 00 80 5e d1 63 (number of data field is 8*1)\n ...\n # a buf: 58 ...                  (number of data field is 8*2)\n ...\n # 64 buf: 58 ...                 (number of data field is 8*13)\n # 65 buf: 58 ...                 (number of data field is 8*13+4)\n\nAfter applying this change, the number of data field keeps being 8*N+4\nconsistently.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05",
              "status": "affected",
              "versionType": "git",
              "lessThan": "7c9f0ccf9f04142458d2ac3d39414f4acae242f0"
            },
            {
              "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05",
              "status": "affected",
              "versionType": "git",
              "lessThan": "24c3fa71f9947b0e1f3b954db1b769b44140192e"
            },
            {
              "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05",
              "status": "affected",
              "versionType": "git",
              "lessThan": "14057268e79654c3e8ea2c9b5204cb9644b2964d"
            },
            {
              "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05",
              "status": "affected",
              "versionType": "git",
              "lessThan": "dbcb8635b1eb7603818591cf745c7b1d714f7ac6"
            },
            {
              "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05",
              "status": "affected",
              "versionType": "git",
              "lessThan": "cfada73fabe2ccc06ec77fe2ceaa088689213326"
            },
            {
              "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05",
              "status": "affected",
              "versionType": "git",
              "lessThan": "ec5e96aee75d27779b9a860307679f13f33adb0c"
            },
            {
              "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05",
              "status": "affected",
              "versionType": "git",
              "lessThan": "3a63a11897c7ba32d1be7a3fdbc48a8b01cf4992"
            },
            {
              "version": "2271048d1b3b0aabf83d25b29c20646dcabedc05",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c37e0a4b79a6bbb96ce5ffe279d7c001e20529e0"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "2.6.34",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "2.6.34"
            },
            {
              "version": "5.10.261",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "version": "5.15.212",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "6.1.178",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "version": "6.6.145",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.97",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.40",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "7.1.5",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "version": "7.2",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}