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CVE-2026-72196

Estado: RecibidaAlta (8.4)—

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

fs/ntfs3: bound copy_lcns dp->page_lcns[] index in analysis pass

In log_replay()'s analysis pass, after find_dp() returns a valid DIR_PAGE_ENTRY for the (target_attr, target_vcn) tuple, the copy_lcns block walks lrh->lcns_follow further entries:

find_dp() only validates that target_vcn falls within [dp->vcn, dp->vcn + dp->lcns_follow), i.e., that the FIRST cluster is covered. The walk through the further entries is not bounded against dp->lcns_follow. For a malformed LRH where target_vcn = dp->vcn + dp->lcns_follow - 1 and lrh->lcns_follow > 1, the i > 0 writes overflow the dp's allocated page_lcns[] array.

Leer descripción completaMostrar menos

Add the missing j + lrh->lcns_follow <= dp->lcns_follow guard.

Reproduced under UML+KASAN on mainline 8d90b09e6741 as a slab-out-of-bounds write of size 8 from log_replay+0x68d4 on the mount path.

This is distinct from Pavitra Jha's 2026-05-02 patch ("fs/ntfs3: validate lcns_follow in log_replay conversion", <20260502154252.164586-1-jhapavitra98@gmail.com>) which addresses the separate version-0 dirty-page-table conversion path's memmove(&dp->vcn, ...) call. The two fixes are complementary; both should land.

[almaz.alexandrovich@paragon-software.com: clang-formatted the changes, fixed conflicts]

Detalles técnicos trazas, registros y código del informe original
	t16 = le16_to_cpu(lrh->lcns_follow);
	for (i = 0; i < t16; i++) {
	    size_t j = (size_t)(le64_to_cpu(lrh->target_vcn) -
	                        le64_to_cpu(dp->vcn));
	    dp->page_lcns[j + i] = lrh->page_lcns[i];
	}

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.

AV:L, PR:N, UI:N → escalada local sin interacción. Buffer overflow en kernel NTFS3 permite escritura fuera de límites (slab-out-of-bounds) comprometiendo integridad de datos y disponibilidad del sistema.

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 ProgramRestrict File and Directory PermissionsRemote Data StorageFilter Network TrafficExecution PreventionEncrypt Sensitive Information

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)

Mostrar
{
  "id": "CVE-2026-72196",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.4,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.5
      }
    ]
  },
  "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": "b46acd6a6a627d876898e1c84d3f84902264b445",
              "lessThan": "9b3d8cc9d54fcded4de51b2b1026ae7182512077",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b46acd6a6a627d876898e1c84d3f84902264b445",
              "lessThan": "9b7c28d8c61bdb041936222a09a708531a1c2921",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b46acd6a6a627d876898e1c84d3f84902264b445",
              "lessThan": "0f13e823bf86bd1800168ea0bb5bca8b8500a81c",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b46acd6a6a627d876898e1c84d3f84902264b445",
              "lessThan": "d240cd98f5f7b65c90f6b2b6abe3232ccdc405ab",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b46acd6a6a627d876898e1c84d3f84902264b445",
              "lessThan": "49c86dae0c0ccb8d98ddcdc46987259389c816dd",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b46acd6a6a627d876898e1c84d3f84902264b445",
              "lessThan": "5e7b598660cfa8e5af172cf4c65cffc126333307",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/ntfs3/fslog.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.15",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/ntfs3/fslog.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-15T06:21:38.200",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0f13e823bf86bd1800168ea0bb5bca8b8500a81c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/49c86dae0c0ccb8d98ddcdc46987259389c816dd",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5e7b598660cfa8e5af172cf4c65cffc126333307",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9b3d8cc9d54fcded4de51b2b1026ae7182512077",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9b7c28d8c61bdb041936222a09a708531a1c2921",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d240cd98f5f7b65c90f6b2b6abe3232ccdc405ab",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/ntfs3: bound copy_lcns dp->page_lcns[] index in analysis pass\n\nIn log_replay()'s analysis pass, after find_dp() returns a\nvalid DIR_PAGE_ENTRY for the (target_attr, target_vcn) tuple,\nthe copy_lcns block walks lrh->lcns_follow further entries:\n\n\tt16 = le16_to_cpu(lrh->lcns_follow);\n\tfor (i = 0; i < t16; i++) {\n\t    size_t j = (size_t)(le64_to_cpu(lrh->target_vcn) -\n\t                        le64_to_cpu(dp->vcn));\n\t    dp->page_lcns[j + i] = lrh->page_lcns[i];\n\t}\n\nfind_dp() only validates that target_vcn falls within\n[dp->vcn, dp->vcn + dp->lcns_follow), i.e., that the FIRST\ncluster is covered.  The walk through the further entries is\nnot bounded against dp->lcns_follow.  For a malformed LRH\nwhere target_vcn = dp->vcn + dp->lcns_follow - 1 and\nlrh->lcns_follow > 1, the i > 0 writes overflow the dp's\nallocated page_lcns[] array.\n\nAdd the missing j + lrh->lcns_follow <= dp->lcns_follow guard.\n\nReproduced under UML+KASAN on mainline 8d90b09e6741 as a\nslab-out-of-bounds write of size 8 from log_replay+0x68d4 on\nthe mount path.\n\nThis is distinct from Pavitra Jha's 2026-05-02 patch\n(\"fs/ntfs3: validate lcns_follow in log_replay conversion\",\n<20260502154252.164586-1-jhapavitra98@gmail.com>) which\naddresses the separate version-0 dirty-page-table conversion\npath's memmove(&dp->vcn, ...) call.  The two fixes are\ncomplementary; both should land.\n\n[almaz.alexandrovich@paragon-software.com: clang-formatted the changes,\nfixed conflicts]"
    }
  ],
  "lastModified": "2026-08-17T06:18:20.347",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}