{
  "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-2021-47649",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-47649",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2025-02-26T01:54:16.574Z",
    "updatedAt": "2026-05-11T13:58:35.146Z",
    "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": "udmabuf: validate ubuf->pagecount",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nudmabuf: validate ubuf->pagecount\n\nSyzbot has reported GPF in sg_alloc_append_table_from_pages(). The\nproblem was in ubuf->pages == ZERO_PTR.\n\nubuf->pagecount is calculated from arguments passed from user-space. If\nuser creates udmabuf with list.size == 0 then ubuf->pagecount will be\nalso equal to zero; it causes kmalloc_array() to return ZERO_PTR.\n\nFix it by validating ubuf->pagecount before passing it to\nkmalloc_array().",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "fbb0de795078190a9834b3409e4b009cfb18a6d4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "5d50f851dd307c07ca5591297093f19967c834a9"
            },
            {
              "version": "fbb0de795078190a9834b3409e4b009cfb18a6d4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b267a8118c2b171bf7d67b90ed64154eeab9fae0"
            },
            {
              "version": "fbb0de795078190a9834b3409e4b009cfb18a6d4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "811b667cefbea9cb7511a874b169d6a92907137e"
            },
            {
              "version": "fbb0de795078190a9834b3409e4b009cfb18a6d4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a3728d32fc61eb0fe283cb8ff60b2c8f751e2202"
            },
            {
              "version": "fbb0de795078190a9834b3409e4b009cfb18a6d4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "9e9b4a269f84d3230f2af84ff42322db676440d9"
            },
            {
              "version": "fbb0de795078190a9834b3409e4b009cfb18a6d4",
              "status": "affected",
              "versionType": "git",
              "lessThan": "2b6dd600dd72573c23ea180b5b0b2f1813405882"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "4.20",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "4.20"
            },
            {
              "version": "5.4.189",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.4.*"
            },
            {
              "version": "5.10.110",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "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": "*"
            }
          ]
        }
      ]
    }
  }
}