CVE-2025-38488

Estado: ModificadaAlta (7.8)—

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

smb: client: fix use-after-free in crypt_message when using async crypto

The CVE-2024-50047 fix removed asynchronous crypto handling from crypt_message(), assuming all crypto operations are synchronous. However, when hardware crypto accelerators are used, this can cause use-after-free crashes:

Hardware crypto modules often implement async AEAD operations for performance. When crypto_aead_encrypt/decrypt() returns -EINPROGRESS, the operation completes asynchronously. Without crypto_wait_req(), the function immediately frees the request buffer, leading to crashes when the driver later accesses the freed memory.

Leer descripción completaMostrar menos

This results in a use-after-free condition when the hardware crypto driver later accesses the freed request structure, leading to kernel crashes with NULL pointer dereferences.

The issue occurs because crypto_alloc_aead() with mask=0 doesn't guarantee synchronous operation. Even without CRYPTO_ALG_ASYNC in the mask, async implementations can be selected.

Fix by restoring the async crypto handling: - DECLARE_CRYPTO_WAIT(wait) for completion tracking - aead_request_set_callback() for async completion notification - crypto_wait_req() to wait for operation completion

This ensures the request buffer isn't freed until the crypto operation completes, whether synchronous or asynchronous, while preserving the CVE-2024-50047 fix.

Detalles técnicos trazas, registros y código del informe original

  crypt_message()
    // Allocate the creq buffer containing the req
    creq = smb2_get_aead_req(..., &req);

    // Async encryption returns -EINPROGRESS immediately
    rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);

    // Free creq while async operation is still in progress
    kvfree_sensitive(creq, ...);

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: 0.68%
Percentil entre todas las CVEs puntuadas: 51
Fecha de la puntuación: 6/10/2026

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 principalT1059 Command and Scripting Interpreterexecution75 %

Vulnerabilidad de uso-after-free (CWE-416) en kernel Linux con acceso local no privilegiado (AV:L/PR:L) que permite ejecución de código arbitrario y crash del sistema (C:H/I:H/A:H).

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 (2)

Debian — Debian Linux Linux — Linux Kernel

CWE

CWE-416

Referencias

JSON original (NVD)

Mostrar

{
  "id": "CVE-2025-38488",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 9.8,
          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/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": 3.9
      },
      {
        "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
      }
    ]
  },
  "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": "8f14a476abba13144df5434871a7225fd29af633",
              "lessThan": "5d047b12f86cc3b9fde1171c02d9bccf4dba0632",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "ef51c0d544b1518b35364480317ab6d3468f205d",
              "lessThan": "6550b2bef095d0dd2d2c8390d2ea4c3837028833",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "bce966530fd5542bbb422cb45ecb775f7a1a6bc3",
              "lessThan": "9a1d3e8d40f151c2d5a5f40c410e6e433f62f438",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "0809fb86ad13b29e1d6d491364fc7ea4fb545995",
              "lessThan": "15a0a5de49507062bc3be4014a403d8cea5533de",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b0abcd65ec545701b8793e12bc27dc98042b151a",
              "lessThan": "2a76bc2b24ed889a689fb1c9015307bf16aafb5b",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b0abcd65ec545701b8793e12bc27dc98042b151a",
              "lessThan": "8ac90f6824fc44d2e55a82503ddfc95defb19ae0",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "b0abcd65ec545701b8793e12bc27dc98042b151a",
              "lessThan": "b220bed63330c0e1733dc06ea8e75d5b9962b6b6",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "538c26d9bf70c90edc460d18c81008a4e555925a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "5.10.237",
              "lessThan": "5.10.241",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "5.15.181",
              "lessThan": "5.15.190",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "6.1.128",
              "lessThan": "6.1.147",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "6.6.57",
              "lessThan": "6.6.100",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "6.11.4",
              "lessThan": "6.12",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "fs/smb/client/smb2ops.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": "5.10.241",
              "versionType": "semver",
              "lessThanOrEqual": "5.10.*"
            },
            {
              "status": "unaffected",
              "version": "5.15.190",
              "versionType": "semver",
              "lessThanOrEqual": "5.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.1.147",
              "versionType": "semver",
              "lessThanOrEqual": "6.1.*"
            },
            {
              "status": "unaffected",
              "version": "6.6.100",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "status": "unaffected",
              "version": "6.12.40",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "status": "unaffected",
              "version": "6.15.8",
              "versionType": "semver",
              "lessThanOrEqual": "6.15.*"
            },
            {
              "status": "unaffected",
              "version": "6.16",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/smb/client/smb2ops.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2025-07-28T12:15:30.857",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/15a0a5de49507062bc3be4014a403d8cea5533de",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/2a76bc2b24ed889a689fb1c9015307bf16aafb5b",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5d047b12f86cc3b9fde1171c02d9bccf4dba0632",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/6550b2bef095d0dd2d2c8390d2ea4c3837028833",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8ac90f6824fc44d2e55a82503ddfc95defb19ae0",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9a1d3e8d40f151c2d5a5f40c410e6e433f62f438",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b220bed63330c0e1733dc06ea8e75d5b9962b6b6",
      "tags": [
        "Patch"
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: fix use-after-free in crypt_message when using async crypto\n\nThe CVE-2024-50047 fix removed asynchronous crypto handling from\ncrypt_message(), assuming all crypto operations are synchronous.\nHowever, when hardware crypto accelerators are used, this can cause\nuse-after-free crashes:\n\n  crypt_message()\n    // Allocate the creq buffer containing the req\n    creq = smb2_get_aead_req(..., &req);\n\n    // Async encryption returns -EINPROGRESS immediately\n    rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req);\n\n    // Free creq while async operation is still in progress\n    kvfree_sensitive(creq, ...);\n\nHardware crypto modules often implement async AEAD operations for\nperformance. When crypto_aead_encrypt/decrypt() returns -EINPROGRESS,\nthe operation completes asynchronously. Without crypto_wait_req(),\nthe function immediately frees the request buffer, leading to crashes\nwhen the driver later accesses the freed memory.\n\nThis results in a use-after-free condition when the hardware crypto\ndriver later accesses the freed request structure, leading to kernel\ncrashes with NULL pointer dereferences.\n\nThe issue occurs because crypto_alloc_aead() with mask=0 doesn't\nguarantee synchronous operation. Even without CRYPTO_ALG_ASYNC in\nthe mask, async implementations can be selected.\n\nFix by restoring the async crypto handling:\n- DECLARE_CRYPTO_WAIT(wait) for completion tracking\n- aead_request_set_callback() for async completion notification\n- crypto_wait_req() to wait for operation completion\n\nThis ensures the request buffer isn't freed until the crypto operation\ncompletes, whether synchronous or asynchronous, while preserving the\nCVE-2024-50047 fix."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: smb: cliente: corrección del use-after-free en crypt_message al usar criptografía asíncrona. La corrección CVE-2024-50047 eliminó el manejo de criptografía asíncrona de crypt_message(), asumiendo que todas las operaciones de criptografía son síncronas. Sin embargo, cuando se usan aceleradores de criptografía de hardware, esto puede causar fallos de use-after-free: crypt_message() // Asignar el búfer creq que contiene la solicitud creq = smb2_get_aead_req(..., &amp;req); // El cifrado asíncrono devuelve -EINPROGRESS inmediatamente rc = enc ? crypto_aead_encrypt(req) : crypto_aead_decrypt(req); // Liberar creq mientras la operación asíncrona aún está en progreso kvfree_sensitive(creq, ...); Los módulos de criptografía de hardware a menudo implementan operaciones AEAD asíncronas para mejorar el rendimiento. Cuando crypto_aead_encrypt/decrypt() devuelve -EINPROGRESS, la operación se completa de forma asíncrona. Sin crypto_wait_req(), la función libera inmediatamente el búfer de solicitud, lo que provoca fallos cuando el controlador accede posteriormente a la memoria liberada. Esto genera una condición de use-after-free cuando el controlador de cifrado de hardware accede posteriormente a la estructura de solicitud liberada, lo que provoca fallos del kernel con desreferencias de punteros NULL. El problema se produce porque crypto_alloc_aead() con mask=0 no garantiza la operación síncrona. Incluso sin CRYPTO_ALG_ASYNC en la máscara, se pueden seleccionar implementaciones asíncronas. Solución restaurando el manejo de criptografía asíncrona: - DECLARE_CRYPTO_WAIT(wait) para seguimiento de finalización - aead_request_set_callback() para notificación de finalización asíncrona - crypto_wait_req() para esperar a que se complete la operación Esto garantiza que el búfer de solicitud no se libere hasta que se complete la operación de criptografía, ya sea sincrónica o asincrónica, al tiempo que se conserva la corrección CVE-2024-50047."
    }
  ],
  "lastModified": "2026-07-30T06:23:20.950",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "79C9B191-D12F-428B-9EEA-30BDCC83120A",
              "versionEndExcluding": "5.10.241",
              "versionStartIncluding": "5.10.237"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "61ADEC7C-D645-4175-8A33-7EB9E14A8FF4",
              "versionEndExcluding": "5.15.190",
              "versionStartIncluding": "5.15.181"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "8D856FFA-04F3-4A37-9907-A0BCF6B2031E",
              "versionEndExcluding": "6.1.147",
              "versionStartIncluding": "6.1.128"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A4038CF7-63A2-4668-9428-4300CE199E7F",
              "versionEndExcluding": "6.6.100",
              "versionStartIncluding": "6.6.57"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "B5676E16-8352-46DA-ADBA-D1030B261D95",
              "versionEndExcluding": "6.12.40",
              "versionStartIncluding": "6.11.4"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "C7AFE5B0-F3B1-4D30-B8BF-EDA0385C4746",
              "versionEndExcluding": "6.15.8",
              "versionStartIncluding": "6.13"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6D4894DB-CCFE-4602-B1BF-3960B2E19A01"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc2:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "09709862-E348-4378-8632-5A7813EDDC86"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc3:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "415BF58A-8197-43F5-B3D7-D1D63057A26E"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc4:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "A0517869-312D-4429-80C2-561086E1421C"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc5:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "85421F4E-C863-4ABF-B4B4-E887CC2F7F92"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:rc6:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "3827F0D4-5FEE-4181-B267-5A45E7CA11FC"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "FA6FEEC2-9F11-4643-8827-749718254FED"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}