« Volver al listado

CVE-2024-56740

Estado: ModificadaAlta (7.8)—

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

nfs/localio: must clear res.replen in nfs_local_read_done

This is easily reproduced with NFSv3 LOCALIO that is servicing reads when it is made to pivot back to using normal RPC. This switch back to using normal NFSv3 with RPC can occur for a few reasons but this issue was exposed with a test that stops and then restarts the NFSv3 server while LOCALIO is performing heavy read IO.

Detalles técnicos trazas, registros y código del informe original
Otherwise memory corruption can occur due to NFSv3 LOCALIO reads
leaving garbage in res.replen:
- nfs3_read_done() copies that into server->read_hdrsize; from there
  nfs3_proc_read_setup() copies it to args.replen in new requests.
- nfs3_xdr_enc_read3args() passes that to rpc_prepare_reply_pages()
  which includes it in hdrsize for xdr_init_pages, so that rq_rcv_buf
  contains a ridiculous len.
- This is copied to rq_private_buf and xs_read_stream_request()
  eventually passes the kvec to sock_recvmsg() which receives incoming
  data into entirely the wrong place.

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 corrupción de memoria (CWE-787) en kernel Linux con AV:L/PR:L/UI:N permite escalada de privilegios. Impactos: ejecución de código y corrupción de datos en transferencias NFS v3.

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 PreventionThreat Intelligence ProgramRestrict Web-Based ContentRestrict File and Directory PermissionsPrivileged Account ManagementRemote Data Storage

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2024-56740",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2024-56740",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2025-10-01T19:57:38.126609Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "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
      },
      {
        "type": "Secondary",
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "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": "70ba381e1a431245c137ed597ec6a05991c79bd9",
              "lessThan": "de5dac261eeab99762bbdf7c20cee5d26ef4462e",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "70ba381e1a431245c137ed597ec6a05991c79bd9",
              "lessThan": "650703bc4ed3edf841e851c99ab8e7ba9e5262a3",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/nfs/localio.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.12"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.12",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.12.2",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.13",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/nfs/localio.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2024-12-29T12:15:07.360",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/650703bc4ed3edf841e851c99ab8e7ba9e5262a3",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/de5dac261eeab99762bbdf7c20cee5d26ef4462e",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ]
    },
    {
      "type": "Secondary",
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "description": [
        {
          "lang": "en",
          "value": "CWE-787"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfs/localio: must clear res.replen in nfs_local_read_done\n\nOtherwise memory corruption can occur due to NFSv3 LOCALIO reads\nleaving garbage in res.replen:\n- nfs3_read_done() copies that into server->read_hdrsize; from there\n  nfs3_proc_read_setup() copies it to args.replen in new requests.\n- nfs3_xdr_enc_read3args() passes that to rpc_prepare_reply_pages()\n  which includes it in hdrsize for xdr_init_pages, so that rq_rcv_buf\n  contains a ridiculous len.\n- This is copied to rq_private_buf and xs_read_stream_request()\n  eventually passes the kvec to sock_recvmsg() which receives incoming\n  data into entirely the wrong place.\n\nThis is easily reproduced with NFSv3 LOCALIO that is servicing reads\nwhen it is made to pivot back to using normal RPC.  This switch back\nto using normal NFSv3 with RPC can occur for a few reasons but this\nissue was exposed with a test that stops and then restarts the NFSv3\nserver while LOCALIO is performing heavy read IO."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: nfs/localio: debe borrar res.replen en nfs_local_read_done De lo contrario, puede producirse corrupción de memoria debido a que las lecturas LOCALIO de NFSv3 dejan basura en res.replen: - nfs3_read_done() copia eso en server->read_hdrsize; desde allí, nfs3_proc_read_setup() lo copia en args.replen en nuevas solicitudes. - nfs3_xdr_enc_read3args() pasa eso a rpc_prepare_reply_pages() que lo incluye en hdrsize para xdr_init_pages, de modo que rq_rcv_buf contiene una longitud ridícula. - Esto se copia a rq_private_buf y xs_read_stream_request() eventualmente pasa el kvec a sock_recvmsg() que recibe datos entrantes en un lugar completamente equivocado. Esto se reproduce fácilmente con NFSv3 LOCALIO, que está prestando servicio a las lecturas, cuando se le obliga a volver a utilizar RPC normal. Este cambio a utilizar NFSv3 normal con RPC puede ocurrir por varias razones, pero este problema se expuso con una prueba que detiene y luego reinicia el servidor NFSv3 mientras LOCALIO realiza operaciones de E/S de lectura pesadas."
    }
  ],
  "lastModified": "2026-06-17T08:12:52.720",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D8882B1B-2ABC-4838-AC1D-DBDBB5764776",
              "versionEndExcluding": "6.12.2",
              "versionStartIncluding": "6.12"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}