{
  "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-2021-47646",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47646",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2025-02-26T01:54:15.122Z",
    "updatedAt": "2026-08-11T02:05:32.009Z",
    "importedAt": "2026-10-24T01:56:36.661Z",
    "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": "Revert \"Revert \"block, bfq: honor already-setup queue merges\"\"",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nRevert \"Revert \"block, bfq: honor already-setup queue merges\"\"\n\nA crash [1] happened to be triggered in conjunction with commit\n2d52c58b9c9b (\"block, bfq: honor already-setup queue merges\"). The\nlatter was then reverted by commit ebc69e897e17 (\"Revert \"block, bfq:\nhonor already-setup queue merges\"\"). Yet, the reverted commit was not\nthe one introducing the bug. In fact, it actually triggered a UAF\nintroduced by a different commit, and now fixed by commit d29bd41428cf\n(\"block, bfq: reset last_bfqq_created on group change\").\n\nSo, there is no point in keeping commit 2d52c58b9c9b (\"block, bfq:\nhonor already-setup queue merges\") out. This commit restores it.\n\n[1] https://bugzilla.kernel.org/show_bug.cgi?id=214503",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "430a67f9d6169a7b3e328bceb2ef9542e4153c7c",
              "status": "affected",
              "versionType": "git",
              "lessThan": "65d8a737452e88f251fe5d925371de6d606df613"
            },
            {
              "version": "430a67f9d6169a7b3e328bceb2ef9542e4153c7c",
              "status": "affected",
              "versionType": "git",
              "lessThan": "abc2129e646af7b43025d90a071f83043f1ae76c"
            },
            {
              "version": "430a67f9d6169a7b3e328bceb2ef9542e4153c7c",
              "status": "affected",
              "versionType": "git",
              "lessThan": "4083925bd6dc89216d156474a8076feec904e607"
            },
            {
              "version": "430a67f9d6169a7b3e328bceb2ef9542e4153c7c",
              "status": "affected",
              "versionType": "git",
              "lessThan": "15729ff8143f8135b03988a100a19e66d7cb7ecd"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.13",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.13"
            },
            {
              "version": "5.15.33",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "version": "5.16.19",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.16.*"
            },
            {
              "version": "5.17.2",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.17.*"
            },
            {
              "version": "5.18",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}