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CVE-2026-97991

Estado: RecibidaAlta (7.8)—

In the Linux kernel, the following vulnerability has been resolved:

vdpa_sim_blk: reject out-of-range sector starts

vdpasim_blk_check_range() logs an invalid start sector but continues validating the request. The subsequent unsigned capacity subtraction can underflow and let an out-of-range buffer offset reach the data path.

The invalid offset is used by three request paths. VIRTIO_BLK_T_OUT copies guest data to blk->buffer + offset through vringh_iov_pull_iotlb(), causing an out-of-bounds write in _copy_from_iter() or memcpy(). VIRTIO_BLK_T_IN copies from blk->buffer + offset to the guest through vringh_iov_push_iotlb(), causing an out-of-bounds read in _copy_to_iter(). VIRTIO_BLK_T_WRITE_ZEROES passes blk->buffer + offset to memset(), causing an out-of-bounds write.

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Reject starts at or beyond the capacity before the subtraction. Treat the capacity boundary as invalid because the IN and OUT paths round byte counts down to sectors for validation but later copy the original byte counts. A sub-sector request at the capacity boundary would otherwise still access past the end of the buffer.

I found this bug myself, though the patch was written with AI assistance.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Vulnerabilidad de escalada de privilegios en kernel Linux (AV:L/PR:L) mediante desbordamiento de buffer sin firmado en vdpa_sim_blk. El atacante con acceso local causa lectura/escritura fuera de límites y denegación de servicio.

Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Threat Intelligence ProgramFilter Network TrafficExecution PreventionApplication Isolation and SandboxingExploit ProtectionUpdate Software

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux KernelAI

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-97991",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "CHANGED",
          "version": "3.1",
          "baseScore": 7.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 6,
        "exploitabilityScore": 1.1
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7d189f617f83f780915b737896a696ff605bd19f",
              "lessThan": "2ff2a8d063fdfa1e1479fb1fe2e3356a2ce89018",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "7d189f617f83f780915b737896a696ff605bd19f",
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              "versionType": "git"
            },
            {
              "status": "affected",
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              "lessThan": "000c6300776ceaf6b715780113f4275b1be4195b",
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            },
            {
              "status": "affected",
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            {
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            {
              "status": "affected",
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              "versionType": "git"
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            {
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              "versionType": "git"
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          ],
          "programFiles": [
            "drivers/vdpa/vdpa_sim/vdpa_sim_blk.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.13"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.13",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.15.222",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.189",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.158",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc3",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/vdpa/vdpa_sim/vdpa_sim_blk.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-25T11:17:27.220",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/000c6300776ceaf6b715780113f4275b1be4195b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/0a8693f00c408d85f086ad85d29e7030bf1e2055",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/14acb0d44b7d90a077beb7b92b444b90bafda9d9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2ff2a8d063fdfa1e1479fb1fe2e3356a2ce89018",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/36ef4d8527f71648f00347f6ba759f0b7e5e0977",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a8a1413a2cfdbedc896249f461d6d92efbbfe21f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d6dac17e20fd2abd0eb8c09d69fccf7426e12bcf",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvdpa_sim_blk: reject out-of-range sector starts\n\nvdpasim_blk_check_range() logs an invalid start sector but continues\nvalidating the request.  The subsequent unsigned capacity subtraction can\nunderflow and let an out-of-range buffer offset reach the data path.\n\nThe invalid offset is used by three request paths.  VIRTIO_BLK_T_OUT\ncopies guest data to blk->buffer + offset through\nvringh_iov_pull_iotlb(), causing an out-of-bounds write in\n_copy_from_iter() or memcpy().  VIRTIO_BLK_T_IN copies from\nblk->buffer + offset to the guest through vringh_iov_push_iotlb(),\ncausing an out-of-bounds read in _copy_to_iter().\nVIRTIO_BLK_T_WRITE_ZEROES passes blk->buffer + offset to memset(),\ncausing an out-of-bounds write.\n\nReject starts at or beyond the capacity before the subtraction.  Treat the\ncapacity boundary as invalid because the IN and OUT paths round byte counts\ndown to sectors for validation but later copy the original byte counts.  A\nsub-sector request at the capacity boundary would otherwise still access\npast the end of the buffer.\n\nI found this bug myself, though the patch was written with AI assistance."
    }
  ],
  "lastModified": "2026-10-03T11:18:22.853",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}