CVE-2026-43408

Estado: AnalizadaAlta (7.8)—

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

ceph: add a bunch of missing ceph_path_info initializers

ceph_mdsc_build_path() must be called with a zero-initialized ceph_path_info parameter, or else the following ceph_mdsc_free_path_info() may crash.

Example crash (on Linux 6.18.12):

Some of the ceph_mdsc_build_path() callers had initializers, but others had not, even though they were all added by commit 15f519e9f883 ("ceph: fix race condition validating r_parent before applying state"). The ones without initializer are suspectible to random crashes. (I can imagine it could even be possible to exploit this bug to elevate privileges.)

Leer descripción completaMostrar menos

Unfortunately, these Ceph functions are undocumented and its semantics can only be derived from the code. I see that ceph_mdsc_build_path() initializes the structure only on success, but not on error.

Calling ceph_mdsc_free_path_info() after a failed ceph_mdsc_build_path() call does not even make sense, but that's what all callers do, and for it to be safe, the structure must be zero-initialized. The least intrusive approach to fix this is therefore to add initializers everywhere.

Detalles técnicos trazas, registros y código del informe original

  virt_to_cache: Object is not a Slab page!
  WARNING: CPU: 184 PID: 2871736 at mm/slub.c:6732 kmem_cache_free+0x316/0x400
  [...]
  Call Trace:
   [...]
   ceph_open+0x13d/0x3e0
   do_dentry_open+0x134/0x480
   vfs_open+0x2a/0xe0
   path_openat+0x9a3/0x1160
  [...]
  cache_from_obj: Wrong slab cache. names_cache but object is from ceph_inode_info
  WARNING: CPU: 184 PID: 2871736 at mm/slub.c:6746 kmem_cache_free+0x2dd/0x400
  [...]
  kernel BUG at mm/slub.c:634!
  Oops: invalid opcode: 0000 [#1] SMP NOPTI
  RIP: 0010:__slab_free+0x1a4/0x350

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: 0.18%
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 escalation75 %
Impacto principalT1059 Command and Scripting Interpreterexecution60 %

Vulnerabilidad local (AV:L/PR:L) sin interacción que causa crashes en memoria (CWE-476 null pointer) en kernel Linux. El texto sugiere posible escalada de privilegios (privilege elevation) explotando la corrupción de memoria en ceph_mdsc_build_path().

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 Behavior Prevention on Endpoint

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

CWE-476

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2026-43408",
  "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": "db378e6f83ec705c6091c65d482d555edc2b0a72",
              "lessThan": "644b47f0574fd82aeb9d00317eca8d1f2a525c8c",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "15f519e9f883b316d86e2bb6b767a023aafd9d83",
              "lessThan": "8be8911f590813e6f90bc6407ced1b23e50bc5da",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "15f519e9f883b316d86e2bb6b767a023aafd9d83",
              "lessThan": "453df1f4535842bf17ff1885a225e153d7ee3374",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "15f519e9f883b316d86e2bb6b767a023aafd9d83",
              "lessThan": "43323a5934b660afae687e8e4e95ac328615a5c4",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "2bfe45987eb346e299d9f763f9cd05f77011519f",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6.12.48",
              "lessThan": "6.12.78",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "6.16.8",
              "lessThan": "6.17",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "fs/ceph/debugfs.c",
            "fs/ceph/dir.c",
            "fs/ceph/file.c",
            "fs/ceph/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": "6.17"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.17",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.78",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.18.19",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "6.19.9",
              "versionType": "semver",
              "lessThanOrEqual": "6.19.*"
            },
            {
              "status": "unaffected",
              "version": "7.0",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/ceph/debugfs.c",
            "fs/ceph/dir.c",
            "fs/ceph/file.c",
            "fs/ceph/inode.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-05-08T15:16:52.397",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/43323a5934b660afae687e8e4e95ac328615a5c4",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/453df1f4535842bf17ff1885a225e153d7ee3374",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/644b47f0574fd82aeb9d00317eca8d1f2a525c8c",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8be8911f590813e6f90bc6407ced1b23e50bc5da",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nceph: add a bunch of missing ceph_path_info initializers\n\nceph_mdsc_build_path() must be called with a zero-initialized\nceph_path_info parameter, or else the following\nceph_mdsc_free_path_info() may crash.\n\nExample crash (on Linux 6.18.12):\n\n  virt_to_cache: Object is not a Slab page!\n  WARNING: CPU: 184 PID: 2871736 at mm/slub.c:6732 kmem_cache_free+0x316/0x400\n  [...]\n  Call Trace:\n   [...]\n   ceph_open+0x13d/0x3e0\n   do_dentry_open+0x134/0x480\n   vfs_open+0x2a/0xe0\n   path_openat+0x9a3/0x1160\n  [...]\n  cache_from_obj: Wrong slab cache. names_cache but object is from ceph_inode_info\n  WARNING: CPU: 184 PID: 2871736 at mm/slub.c:6746 kmem_cache_free+0x2dd/0x400\n  [...]\n  kernel BUG at mm/slub.c:634!\n  Oops: invalid opcode: 0000 [#1] SMP NOPTI\n  RIP: 0010:__slab_free+0x1a4/0x350\n\nSome of the ceph_mdsc_build_path() callers had initializers, but\nothers had not, even though they were all added by commit 15f519e9f883\n(\"ceph: fix race condition validating r_parent before applying state\").\nThe ones without initializer are suspectible to random crashes.  (I can\nimagine it could even be possible to exploit this bug to elevate\nprivileges.)\n\nUnfortunately, these Ceph functions are undocumented and its semantics\ncan only be derived from the code.  I see that ceph_mdsc_build_path()\ninitializes the structure only on success, but not on error.\n\nCalling ceph_mdsc_free_path_info() after a failed\nceph_mdsc_build_path() call does not even make sense, but that's what\nall callers do, and for it to be safe, the structure must be\nzero-initialized.  The least intrusive approach to fix this is\ntherefore to add initializers everywhere."
    }
  ],
  "lastModified": "2026-06-17T10:49:32.437",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6EC06A5F-045A-48FD-8863-E8AB8E92B0BE",
              "versionEndExcluding": "6.12.78",
              "versionStartIncluding": "6.12.48"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "8C0D11FE-A1CB-4D09-B221-8281514EB44E",
              "versionEndExcluding": "6.17",
              "versionStartIncluding": "6.16.8"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "2B44FFCD-31AB-4CB4-8733-63F887DA5E89",
              "versionEndExcluding": "6.18.19",
              "versionStartIncluding": "6.17.1"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E825E7C3-FEAC-4FD3-8A81-78D7387948C9",
              "versionEndExcluding": "6.19.9",
              "versionStartIncluding": "6.19"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.17:-:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "7CC8B11D-82DC-4958-8DC7-BF5CC829A5E9"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc6:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "5A4516A6-C12E-42A4-8C0E-68AEF3264504"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.17:rc7:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "3963C3A0-CEA1-4F5C-8011-3A593ABB684D"
            },
            {
              "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"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}