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CVE-2026-72367

Estado: RecibidaAlta (8.8)—

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

iomap: guard io_size EOF trim against concurrent truncate underflow

iomap: fix zero padding data issue in concurrent append writes changed ioend accounting so that io_size tracks only valid data within EOF. This trims io_size when a writeback range extends past end_pos:

However, if end_pos ends up below ioend->io_offset, the subtraction becomes negative and is stored in size_t io_size, causing an unsigned wrap to a huge value. This can happen when writeback continues past byte-level EOF up to a block-aligned range, or when a concurrent truncate shrinks the file after end_pos was sampled in iomap_writeback_handle_eof().

Leer descripción completaMostrar menos

A wrapped io_size can mislead append detection and corrupt completion-time size handling, since filesystem end_io paths consume io_size for decisions such as on-disk EOF updates and unwritten/COW completion ranges.

Fix this by clamping io_size to zero when EOF has moved to or before the ioend start offset. This preserves the original intent of trimming io_size to valid in-EOF data while avoiding the underflow.

Detalles técnicos trazas, registros y código del informe original
    ioend->io_size += map_len;
    if (ioend->io_offset + ioend->io_size > end_pos)
        ioend->io_size = end_pos - ioend->io_offset;

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 kernel remota (AV:N, PR:L) en iomap que causa corrupción de datos por underflow de unsigned integer en contexto de escritura concurrente y truncate. Impacta integridad de datos en-disco y disponibilidad por DoS potencial.

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

Vulnerability ScanningThreat Intelligence ProgramRestrict File and Directory PermissionsPrivileged Account ManagementRemote Data StorageNetwork Segmentation

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-2026-72367",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.8,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/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": 2.8
      }
    ]
  },
  "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": "51d20d1dacbec589d459e11fc88fbca419f84a99",
              "lessThan": "1f38f65bf965fce9aa159d45c5347538f56c5973",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "51d20d1dacbec589d459e11fc88fbca419f84a99",
              "lessThan": "7f7780abb4c0fdc9a2603aea8e985ff14ee900e0",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "51d20d1dacbec589d459e11fc88fbca419f84a99",
              "lessThan": "55ec50d046c03b3724741957f7b007856e36dbe7",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "82c59a86a247a8970d353d10f52a37e5564fb137",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6.12.10",
              "lessThan": "6.13",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "fs/iomap/ioend.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.13"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.13",
              "versionType": "semver"
            },
            {
              "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/iomap/ioend.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-15T06:22:10.117",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1f38f65bf965fce9aa159d45c5347538f56c5973",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/55ec50d046c03b3724741957f7b007856e36dbe7",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/7f7780abb4c0fdc9a2603aea8e985ff14ee900e0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niomap: guard io_size EOF trim against concurrent truncate underflow\n\niomap: fix zero padding data issue in concurrent append writes\nchanged ioend accounting so that io_size tracks only valid data\nwithin EOF.  This trims io_size when a writeback range extends\npast end_pos:\n\n    ioend->io_size += map_len;\n    if (ioend->io_offset + ioend->io_size > end_pos)\n        ioend->io_size = end_pos - ioend->io_offset;\n\nHowever, if end_pos ends up below ioend->io_offset, the subtraction\nbecomes negative and is stored in size_t io_size, causing an unsigned\nwrap to a huge value.  This can happen when writeback continues past\nbyte-level EOF up to a block-aligned range, or when a concurrent\ntruncate shrinks the file after end_pos was sampled in\niomap_writeback_handle_eof().\n\nA wrapped io_size can mislead append detection and corrupt\ncompletion-time size handling, since filesystem end_io paths consume\nio_size for decisions such as on-disk EOF updates and unwritten/COW\ncompletion ranges.\n\nFix this by clamping io_size to zero when EOF has moved to or before\nthe ioend start offset.  This preserves the original intent of trimming\nio_size to valid in-EOF data while avoiding the underflow."
    }
  ],
  "lastModified": "2026-08-17T06:18:40.890",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}