{
  "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-2026-45894",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-45894",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-05-27T12:17:04.866Z",
    "updatedAt": "2026-10-21T12:40:56.383Z",
    "importedAt": "2026-10-24T01:58:14.884Z",
    "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": "iommu/vt-d: Clear Present bit before tearing down PASID entry",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\niommu/vt-d: Clear Present bit before tearing down PASID entry\n\nThe Intel VT-d Scalable Mode PASID table entry consists of 512 bits (64\nbytes). When tearing down an entry, the current implementation zeros the\nentire 64-byte structure immediately using multiple 64-bit writes.\n\nSince the IOMMU hardware may fetch these 64 bytes using multiple\ninternal transactions (e.g., four 128-bit bursts), updating or zeroing\nthe entire entry while it is active (P=1) risks a \"torn\" read. If a\nhardware fetch occurs simultaneously with the CPU zeroing the entry, the\nhardware could observe an inconsistent state, leading to unpredictable\nbehavior or spurious faults.\n\nFollow the \"Guidance to Software for Invalidations\" in the VT-d spec\n(Section 6.5.3.3) by implementing the recommended ownership handshake:\n\n1. Clear only the 'Present' (P) bit of the PASID entry.\n2. Use a dma_wmb() to ensure the cleared bit is visible to hardware\n   before proceeding.\n3. Execute the required invalidation sequence (PASID cache, IOTLB, and\n   Device-TLB flush) to ensure the hardware has released all cached\n   references.\n4. Only after the flushes are complete, zero out the remaining fields\n   of the PASID entry.\n\nAlso, add a dma_wmb() in pasid_set_present() to ensure that all other\nfields of the PASID entry are visible to the hardware before the Present\nbit is set.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c36b0515c6445bd137ec8ad86ef5470c45d6e4bf"
            },
            {
              "version": "0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15",
              "status": "affected",
              "versionType": "git",
              "lessThan": "a84d30e8d2bacd21782a6481158b7c9c552f4868"
            },
            {
              "version": "0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15",
              "status": "affected",
              "versionType": "git",
              "lessThan": "821807c167b7b48a41b95b6607c6b9f97600f7d9"
            },
            {
              "version": "0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15",
              "status": "affected",
              "versionType": "git",
              "lessThan": "949d71666e9dd19f21e7b4b53a88cd2c5b902858"
            },
            {
              "version": "0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15",
              "status": "affected",
              "versionType": "git",
              "lessThan": "75ed00055c059dedc47b5daaaa2f8a7a019138ff"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "5.0",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "5.0"
            },
            {
              "version": "6.6.160",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.75",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.18.14",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "version": "6.19.4",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "version": "7.0",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}