CVE-2026-80536

Estado: RecibidaAlta (8.4)—

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

xfs: bounds-check buffer log item's dirty bitmap

xlog_recover_do_reg_buffer() replays each dirty region described by a buffer log item's bitmap into the buffer read for that item:

The destination offset (bit/nbits, from the logged dirty bitmap) and the buffer size (from the logged blf_len) are both attacker-controlled and otherwise unrelated, yet the only thing bounding the copy is an ASSERT(), which compiles away on production kernels.

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A crafted image logging a small blf_len together with a bitmap bit past the end of that buffer drives the memcpy() past the buffer's allocation, corrupting adjacent kernel heap during mount-time log recovery. This is reachable by anyone who can get a crafted image mounted -- the malicious-filesystem threat model XFS already guards against elsewhere.

Turn the ASSERT() into a real XFS_IS_CORRUPT() check that aborts recovery of the buffer with -EFSCORRUPTED, consistent with the validate-and-fail idiom already used in xlog_recover_do_inode_buffer() and xfs_dquot_item_recover.c. xlog_recover_do_reg_buffer() therefore becomes STATIC int and its three callers propagate the error.

Found and confirmed with KASAN on a CONFIG_XFS_DEBUG=n build: the crafted image trips a slab-out-of-bounds write before this change and fails recovery cleanly with -EFSCORRUPTED after it.

Detalles técnicos trazas, registros y código del informe original

	memcpy(xfs_buf_offset(bp, (uint)bit << XFS_BLF_SHIFT),
		item->ri_buf[i].iov_base,
		nbits << XFS_BLF_SHIFT);

CVSS

Versión: 3.1
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Puntuación base: 8.4

Probabilidad de explotación (EPSS)

Probabilidad de explotación en los próximos 30 días: 0.14%
Percentil entre todas las CVEs puntuadas: 3
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 principalT1565.001 Stored Data Manipulationimpact75 %
Impacto secundarioT1499.004 Application or System Exploitationimpact70 %

Acceso local (AV:L) sin interacción del usuario: escalada via corrupción de heap durante mount. Memcpy sin validación de bitmap permite corrupción de memoria adyacente (T1565.001) y denegación de servicio al abortar recovery (T1499.004).

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 Program Restrict File and Directory Permissions Remote Data Storage Filter Network Traffic Execution Prevention Encrypt 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 Kernel^AI

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-80536",
  "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
      }
    ]
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  "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": [
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              "status": "affected",
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              "lessThan": "acb4e26295e7f0e685815a3fd3d70bd8329cefa1",
              "versionType": "git"
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            {
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "f3859c35a4fbc1c1c58431f684f808e43696891d",
              "versionType": "git"
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            {
              "status": "affected",
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              "status": "affected",
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              "versionType": "git"
            },
            {
              "status": "affected",
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            {
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              "versionType": "git"
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          ],
          "programFiles": [
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          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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          "versions": [
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              "version": "2.6.12"
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            {
              "status": "unaffected",
              "version": "0",
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            {
              "status": "unaffected",
              "version": "5.10.267",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
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            {
              "status": "unaffected",
              "version": "5.15.218",
              "versionType": "semver",
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            },
            {
              "status": "unaffected",
              "version": "6.1.185",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.154",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.106",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.46",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.10",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/xfs/xfs_buf_item_recover.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-26T15:17:07.777",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/7e32d4eebae6ca24f8a673c107fd7eca1f47afc2",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "url": "https://git.kernel.org/stable/c/acb4e26295e7f0e685815a3fd3d70bd8329cefa1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
      "url": "https://git.kernel.org/stable/c/edaf5b6bd625356893da20d69a259b34a9de2694",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f7b5fa83e2c192be922121b764415fa8c7549ea1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f8288214459ead7e87d26e5822f62c14a4f2ed6b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfs: bounds-check buffer log item's dirty bitmap\n\nxlog_recover_do_reg_buffer() replays each dirty region described by a\nbuffer log item's bitmap into the buffer read for that item:\n\n\tmemcpy(xfs_buf_offset(bp, (uint)bit << XFS_BLF_SHIFT),\n\t\titem->ri_buf[i].iov_base,\n\t\tnbits << XFS_BLF_SHIFT);\n\nThe destination offset (bit/nbits, from the logged dirty bitmap) and the\nbuffer size (from the logged blf_len) are both attacker-controlled and\notherwise unrelated, yet the only thing bounding the copy is an ASSERT(),\nwhich compiles away on production kernels. A crafted image logging a\nsmall blf_len together with a bitmap bit past the end of that buffer\ndrives the memcpy() past the buffer's allocation, corrupting adjacent\nkernel heap during mount-time log recovery. This is reachable by anyone\nwho can get a crafted image mounted -- the malicious-filesystem threat\nmodel XFS already guards against elsewhere.\n\nTurn the ASSERT() into a real XFS_IS_CORRUPT() check that aborts recovery\nof the buffer with -EFSCORRUPTED, consistent with the validate-and-fail\nidiom already used in xlog_recover_do_inode_buffer() and\nxfs_dquot_item_recover.c. xlog_recover_do_reg_buffer() therefore becomes\nSTATIC int and its three callers propagate the error.\n\nFound and confirmed with KASAN on a CONFIG_XFS_DEBUG=n build: the crafted\nimage trips a slab-out-of-bounds write before this change and fails\nrecovery cleanly with -EFSCORRUPTED after it."
    }
  ],
  "lastModified": "2026-08-27T13:18:38.940",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}