« Volver al listado

CVE-2026-68172

Estado: RecibidaAlta (7.1)—

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

arm64: make huge_ptep_get handled unaligned addresses

huge_ptep_get() can be handed a virtual address pointing to the middle of a contpmd/contpte mapped hugetlb folio (examples of callers are pagemap_hugetlb_range, page_mapped_in_vma).

The arm64 helper rewalks the pgtables in find_num_contig to answer whether the huge pte we have maps a contpmd or a contpte hugetlb folio, and returns CONT_PMDS or CONT_PTES, so that it can collect a/d bits over the contiguous ptes.

Leer descripción completaMostrar menos

We can falsely return CONT_PTES instead of CONT_PMDS if the addr is not aligned. On systems where CONT_PTES != CONT_PMDS (meaning page size is 16K), we could collect excess A/D bit state, meaning extra work for the kernel. Even worse, we may iterate beyond the PTE table and dereference a garbage ptep pointer to access physical memory we don't own. Since the ptep pointer is a linear map address, we may run off the end of the linear map or into a hole, dereference a VA not mapped into the kernel pgtables and cause kernel panic.

Fix this by aligning the pmdp pointer down to a contpmd base before checking equality with the passed huge pte pointer, to correctly answer whether the huge pte is the base of a contpmd block.

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 local (AV:L/PR:L) que causa kernel panic por dereference de memoria inválida (DoS). Puede provocar corrupción de datos en memoria del kernel (integridad comprometida por A/D bits falsos).

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

Tecnologías afectadas (1)

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

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-68172",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.1,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.2,
        "exploitabilityScore": 1.8
      }
    ]
  },
  "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": "29cb80519689706387bde47000dbb2ed91143063",
              "lessThan": "9cd4b1a52eff330798d668c1775f8bc450776280",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "29cb80519689706387bde47000dbb2ed91143063",
              "lessThan": "f3530aec26563f4d483ff31402392961362e9bc6",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "29cb80519689706387bde47000dbb2ed91143063",
              "lessThan": "f73a8edc2ccc6ec72c37d5c578e7592d2e1f9922",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "arch/arm64/mm/hugetlbpage.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.16",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "arch/arm64/mm/hugetlbpage.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-10T13:20:03.933",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/9cd4b1a52eff330798d668c1775f8bc450776280",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f3530aec26563f4d483ff31402392961362e9bc6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f73a8edc2ccc6ec72c37d5c578e7592d2e1f9922",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\narm64: make huge_ptep_get handled unaligned addresses\n\nhuge_ptep_get() can be handed a virtual address pointing to the middle\nof a contpmd/contpte mapped hugetlb folio (examples of callers are\npagemap_hugetlb_range, page_mapped_in_vma).\n\nThe arm64 helper rewalks the pgtables in find_num_contig to answer\nwhether the huge pte we have maps a contpmd or a contpte hugetlb folio,\nand returns CONT_PMDS or CONT_PTES, so that it can collect a/d bits over\nthe contiguous ptes. We can falsely return CONT_PTES instead of\nCONT_PMDS if the addr is not aligned. On systems where CONT_PTES !=\nCONT_PMDS (meaning page size is 16K), we could collect excess A/D bit\nstate, meaning extra work for the kernel. Even worse, we may iterate\nbeyond the PTE table and dereference a garbage ptep pointer to access\nphysical memory we don't own. Since the ptep pointer is a linear map\naddress, we may run off the end of the linear map or into a hole,\ndereference a VA not mapped into the kernel pgtables and cause kernel\npanic.\n\nFix this by aligning the pmdp pointer down to a contpmd base before\nchecking equality with the passed huge pte pointer, to correctly answer\nwhether the huge pte is the base of a contpmd block."
    }
  ],
  "lastModified": "2026-08-17T05:18:18.650",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}