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CVE-2025-40167

Estado: AplazadaAlta (7.8)—

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

ext4: detect invalid INLINE_DATA + EXTENTS flag combination

syzbot reported a BUG_ON in ext4_es_cache_extent() when opening a verity file on a corrupted ext4 filesystem mounted without a journal.

The issue is that the filesystem has an inode with both the INLINE_DATA and EXTENTS flags set:

This is an invalid combination since an inode should have either: - INLINE_DATA: data stored directly in the inode - EXTENTS: data stored in extent-mapped blocks

Having both flags causes ext4_has_inline_data() to return true, skipping extent tree validation in __ext4_iget(). The unvalidated out-of-order extents then trigger a BUG_ON in ext4_es_cache_extent() due to integer underflow when calculating hole sizes.

Leer descripción completaMostrar menos

Fix this by detecting this invalid flag combination early in ext4_iget() and rejecting the corrupted inode.

Detalles técnicos trazas, registros y código del informe original
    EXT4-fs error (device loop0): ext4_cache_extents:545: inode #15:
    comm syz.0.17: corrupted extent tree: lblk 0 < prev 66

Investigation revealed that the inode has both flags set:
    DEBUG: inode 15 - flag=1, i_inline_off=164, has_inline=1, extents_flag=1

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.

Vector CVSS con UI:R (requiere interacción del usuario: abrir archivo) → T1203. El BUG_ON causa DoS (kernel crash) en la apertura del archivo corrupto; corrupción potencial del sistema de archivos ext4.

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

Filter Network TrafficApplication Isolation and SandboxingExploit ProtectionUpdate SoftwareData Backup

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-2025-40167",
  "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:N/UI:R/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "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": "f19d5870cbf72d4cb2a8e1f749dff97af99b071e",
              "lessThan": "4954d297c91d292630ab43ba4d195dc371ce65d3",
              "versionType": "git"
            },
            {
              "status": "affected",
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              "versionType": "git"
            },
            {
              "status": "affected",
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              "lessThan": "2e9e10657b04152ed0d6ecae8d0c02a3405e28f5",
              "versionType": "git"
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            {
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              "lessThan": "cb6039b68efa547b676a8a10fc4618d9d1865c23",
              "versionType": "git"
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            {
              "status": "affected",
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              "lessThan": "de985264eef64be8a90595908f2e6a87946dad34",
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            },
            {
              "status": "affected",
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              "versionType": "git"
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          ],
          "programFiles": [
            "fs/ext4/inode.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
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              "version": "3.8"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "3.8",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "5.4.301",
              "versionType": "semver",
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            },
            {
              "status": "unaffected",
              "version": "5.10.246",
              "versionType": "semver",
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            },
            {
              "status": "unaffected",
              "version": "5.15.196",
              "versionType": "semver",
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            },
            {
              "status": "unaffected",
              "version": "6.1.158",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.114",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
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              "version": "6.12.55",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.17.5",
              "versionType": "semver",
              "lessThanOrEqual": "6.17.*"
            },
            {
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/ext4/inode.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-11-12T11:15:47.013",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1437c95ab2a28b138d4521653583729f61ccb48b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/1d3ad183943b38eec2acf72a0ae98e635dc8456b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/1f5ccd22ff482639133f2a0fe08f6d19d0e68717",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2e9e10657b04152ed0d6ecae8d0c02a3405e28f5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    },
    {
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f061f7c331fc16250fc82aa68964f35821687217",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Deferred",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\next4: detect invalid INLINE_DATA + EXTENTS flag combination\n\nsyzbot reported a BUG_ON in ext4_es_cache_extent() when opening a verity\nfile on a corrupted ext4 filesystem mounted without a journal.\n\nThe issue is that the filesystem has an inode with both the INLINE_DATA\nand EXTENTS flags set:\n\n    EXT4-fs error (device loop0): ext4_cache_extents:545: inode #15:\n    comm syz.0.17: corrupted extent tree: lblk 0 < prev 66\n\nInvestigation revealed that the inode has both flags set:\n    DEBUG: inode 15 - flag=1, i_inline_off=164, has_inline=1, extents_flag=1\n\nThis is an invalid combination since an inode should have either:\n- INLINE_DATA: data stored directly in the inode\n- EXTENTS: data stored in extent-mapped blocks\n\nHaving both flags causes ext4_has_inline_data() to return true, skipping\nextent tree validation in __ext4_iget(). The unvalidated out-of-order\nextents then trigger a BUG_ON in ext4_es_cache_extent() due to integer\nunderflow when calculating hole sizes.\n\nFix this by detecting this invalid flag combination early in ext4_iget()\nand rejecting the corrupted inode."
    }
  ],
  "lastModified": "2026-07-30T06:24:14.890",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}