CVE-2026-43075

Estado: ModificadaAlta (7.8)—

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

ocfs2: fix out-of-bounds write in ocfs2_write_end_inline

KASAN reports a use-after-free write of 4086 bytes in ocfs2_write_end_inline, called from ocfs2_write_end_nolock during a copy_file_range splice fallback on a corrupted ocfs2 filesystem mounted on a loop device. The actual bug is an out-of-bounds write past the inode block buffer, not a true use-after-free. The write overflows into an adjacent freed page, which KASAN reports as UAF.

The root cause is that ocfs2_try_to_write_inline_data trusts the on-disk id_count field to determine whether a write fits in inline data.

Leer descripción completaMostrar menos

On a corrupted filesystem, id_count can exceed the physical maximum inline data capacity, causing writes to overflow the inode block buffer.

So add id_count upper bound check in ocfs2_validate_inode_block() to alongside the existing i_size check to fix it.

Detalles técnicos trazas, registros y código del informe original

Call trace (crash path):

   vfs_copy_file_range (fs/read_write.c:1634)
     do_splice_direct
       splice_direct_to_actor
         iter_file_splice_write
           ocfs2_file_write_iter
             generic_perform_write
               ocfs2_write_end
                 ocfs2_write_end_nolock (fs/ocfs2/aops.c:1949)
                   ocfs2_write_end_inline (fs/ocfs2/aops.c:1915)
                     memcpy_from_folio     <-- KASAN: write OOB

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 7.8

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.17%
Percentil entre todas las CVEs puntuadas: 6
Fecha de la puntuación: 5/10/2026

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.

ExplotaciónT1068 Exploitation for Privilege Escalationprivilege escalation85 %
Impacto principalT1059 Command and Scripting Interpreterexecution70 %
Impacto secundarioT1499.004 Application or System Exploitationimpact60 %

Vulnerabilidad local de escritura fuera de límites (CWE-787, AV:L, PR:L) en kernel Linux explotable para escalada de privilegios. El overflow en ocfs2_write_end_inline puede permitir ejecución de código o DoS 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

Execution Prevention Threat Intelligence Program Restrict Web-Based Content Privileged Account Management Limit Software Installation Filter Network Traffic

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-787

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-43075",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.8,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "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": "1afc32b952335f665327a1a9001ba1b44bb76fd9",
              "lessThan": "68f9cc3bbf2ae501770cea7dc0005fc9a85e48ea",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1afc32b952335f665327a1a9001ba1b44bb76fd9",
              "lessThan": "2e6a254f9cedf51b75cc20b8b92e2209bfa04c3e",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1afc32b952335f665327a1a9001ba1b44bb76fd9",
              "lessThan": "22df7d4de9c5cd42edf855a1de25f2106088c4c6",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1afc32b952335f665327a1a9001ba1b44bb76fd9",
              "lessThan": "e2c9dc6b6e96f3585f2a1062ca3374a52db0938f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1afc32b952335f665327a1a9001ba1b44bb76fd9",
              "lessThan": "947f953978b0d9463498d548d0f054f5a75be2e9",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1afc32b952335f665327a1a9001ba1b44bb76fd9",
              "lessThan": "0c1af902223b6fcedb60904ca0b551254686c7b9",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1afc32b952335f665327a1a9001ba1b44bb76fd9",
              "lessThan": "69d3c69ade1e4285ab4ca48fe7acee0767e65604",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1afc32b952335f665327a1a9001ba1b44bb76fd9",
              "lessThan": "7bc5da4842bed3252d26e742213741a4d0ac1b14",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/ocfs2/inode.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.24"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "2.6.24",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.10.258",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.209",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.175",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.136",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.83",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.24",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "6.19.14",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/ocfs2/inode.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-05-06T10:16:20.463",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0c1af902223b6fcedb60904ca0b551254686c7b9",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/22df7d4de9c5cd42edf855a1de25f2106088c4c6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2e6a254f9cedf51b75cc20b8b92e2209bfa04c3e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/68f9cc3bbf2ae501770cea7dc0005fc9a85e48ea",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/69d3c69ade1e4285ab4ca48fe7acee0767e65604",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/7bc5da4842bed3252d26e742213741a4d0ac1b14",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/947f953978b0d9463498d548d0f054f5a75be2e9",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e2c9dc6b6e96f3585f2a1062ca3374a52db0938f",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix out-of-bounds write in ocfs2_write_end_inline\n\nKASAN reports a use-after-free write of 4086 bytes in\nocfs2_write_end_inline, called from ocfs2_write_end_nolock during a\ncopy_file_range splice fallback on a corrupted ocfs2 filesystem mounted on\na loop device.  The actual bug is an out-of-bounds write past the inode\nblock buffer, not a true use-after-free.  The write overflows into an\nadjacent freed page, which KASAN reports as UAF.\n\nThe root cause is that ocfs2_try_to_write_inline_data trusts the on-disk\nid_count field to determine whether a write fits in inline data.  On a\ncorrupted filesystem, id_count can exceed the physical maximum inline data\ncapacity, causing writes to overflow the inode block buffer.\n\nCall trace (crash path):\n\n   vfs_copy_file_range (fs/read_write.c:1634)\n     do_splice_direct\n       splice_direct_to_actor\n         iter_file_splice_write\n           ocfs2_file_write_iter\n             generic_perform_write\n               ocfs2_write_end\n                 ocfs2_write_end_nolock (fs/ocfs2/aops.c:1949)\n                   ocfs2_write_end_inline (fs/ocfs2/aops.c:1915)\n                     memcpy_from_folio     <-- KASAN: write OOB\n\nSo add id_count upper bound check in ocfs2_validate_inode_block() to\nalongside the existing i_size check to fix it."
    }
  ],
  "lastModified": "2026-06-17T10:48:53.263",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "3C45350C-5A79-40F0-B6B0-BF9ED7FA81B4",
              "versionEndExcluding": "6.6.136",
              "versionStartIncluding": "2.6.24.1"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "7F0AE5B5-23AC-4DCC-B37A-51CA1DAE7BA8",
              "versionEndExcluding": "6.12.83",
              "versionStartIncluding": "6.7"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "8126B8B8-6D0B-4443-86C1-672AEE893555",
              "versionEndExcluding": "6.18.24",
              "versionStartIncluding": "6.13"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D6A8A074-BBF4-4803-ABED-519A839435BB",
              "versionEndExcluding": "6.19.14",
              "versionStartIncluding": "6.19"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:2.6.24:-:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6F3E61F3-1CF1-4176-94CD-89A408BCFC96"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F253B622-8837-4245-BCE5-A7BF8FC76A16"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "4AE85AD8-4641-4E7C-A2F4-305E2CD9EE64"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F666C8D8-6538-46D4-B318-87610DE64C34"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "02259FDA-961B-47BC-AE7F-93D7EC6E90C2"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc5:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "58A9FEFF-C040-420D-8F0A-BFDAAA1DF258"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc6:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "1D2315C0-D46F-4F85-9754-F9E5E11374A6"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.0:rc7:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "512EE3A8-A590-4501-9A94-5D4B268D6138"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}