CVE-2026-89751 (GCVE-0-2026-89751)
Vulnerability from cvelistv5
Published
2026-09-11 19:46
Modified
2026-10-19 08:52
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: x86/tdx: Fix off-by-one in port I/O handling handle_in() and handle_out() in arch/x86/coco/tdx/tdx.c use: u64 mask = GENMASK(BITS_PER_BYTE * size, 0); GENMASK(h, l) includes bit h. For size=1 (INB), this produces GENMASK(8, 0) = 0x1FF (9 bits) instead of GENMASK(7, 0) = 0xFF (8 bits). The mask is one bit too wide for all I/O sizes. Fix the mask calculation.
References
Impacted products
Vendor Product Version
Linux Linux Version: 03149948832a078f759022ed5b92e722d8d23c26
Version: 03149948832a078f759022ed5b92e722d8d23c26
Version: 03149948832a078f759022ed5b92e722d8d23c26
Version: 03149948832a078f759022ed5b92e722d8d23c26
Version: 03149948832a078f759022ed5b92e722d8d23c26
Version: 03149948832a078f759022ed5b92e722d8d23c26
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{
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      "cpeApplicability": [
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          "nodes": [
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/tdx: Fix off-by-one in port I/O handling\n\nhandle_in() and handle_out() in arch/x86/coco/tdx/tdx.c use:\n\n    u64 mask = GENMASK(BITS_PER_BYTE * size, 0);\n\nGENMASK(h, l) includes bit h. For size=1 (INB), this produces\nGENMASK(8, 0) = 0x1FF (9 bits) instead of GENMASK(7, 0) = 0xFF (8\nbits). The mask is one bit too wide for all I/O sizes.\n\nFix the mask calculation."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T08:52:05.025Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c6875423ad849ac234ab9812eb72f37ff8a490b4"
        },
        {
          "url": "https://git.kernel.org/stable/c/220011fe95fc78b2bc2d7d43893bc73957a5c811"
        },
        {
          "url": "https://git.kernel.org/stable/c/222b7005e4519f633b4cd666226256abbab46a1a"
        },
        {
          "url": "https://git.kernel.org/stable/c/c4a22154870813d10aa0b4c734a574c726f9d4b0"
        },
        {
          "url": "https://git.kernel.org/stable/c/bb45f705c4440dd3c689328319b88dd28770bbb8"
        },
        {
          "url": "https://git.kernel.org/stable/c/0f63e656b1c679d32ac595de29d10c03efca6a25"
        }
      ],
      "title": "x86/tdx: Fix off-by-one in port I/O handling",
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  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-89751",
    "datePublished": "2026-09-11T19:46:55.314Z",
    "dateReserved": "2026-09-11T19:38:34.762Z",
    "dateUpdated": "2026-10-19T08:52:05.025Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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