{
  "id": "CVE-2024-56549",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2024-12-27T14:15:34.747",
  "lastModified": "2025-02-21T14:15:50.947",
  "vulnStatus": "Modified",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: Fix NULL pointer dereference in object->file\n\nAt present, the object->file has the NULL pointer dereference problem in\nondemand-mode. The root cause is that the allocated fd and object->file\nlifetime are inconsistent, and the user-space invocation to anon_fd uses\nobject->file. Following is the process that triggers the issue:\n\n\t  [write fd]\t\t\t\t[umount]\ncachefiles_ondemand_fd_write_iter\n\t\t\t\t       fscache_cookie_state_machine\n\t\t\t\t\t cachefiles_withdraw_cookie\n  if (!file) return -ENOBUFS\n\t\t\t\t\t   cachefiles_clean_up_object\n\t\t\t\t\t     cachefiles_unmark_inode_in_use\n\t\t\t\t\t     fput(object->file)\n\t\t\t\t\t     object->file = NULL\n  // file NULL pointer dereference!\n  __cachefiles_write(..., file, ...)\n\nFix this issue by add an additional reference count to the object->file\nbefore write/llseek, and decrement after it finished."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: cachefiles: Arreglar la desreferencia de puntero NULL en object->file En la actualidad, object->file tiene el problema de desreferencia de puntero NULL en el modo ondemand. La causa ra\u00edz es que el fd asignado y el tiempo de vida de object->file son inconsistentes, y la invocaci\u00f3n del espacio de usuario a anon_fd usa object->file. A continuaci\u00f3n, se muestra el proceso que desencadena el problema: [write fd] [umount] cachefiles_ondemand_fd_write_iter fscache_cookie_state_machine cachefiles_withdraw_cookie if (!file) return -ENOBUFS cachefiles_clean_up_object cachefiles_unmark_inode_in_use fput(object->file) object->file = NULL // file \u00a1Desreferencia de puntero NULL! __cachefiles_write(..., file, ...) Solucione este problema agregando un recuento de referencia adicional al objeto->archivo antes de escribir/llseek, y disminuya despu\u00e9s de que finalice."
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "nvd@nist.gov",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6
      }
    ]
  },
  "weaknesses": [
    {
      "source": "nvd@nist.gov",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ]
    }
  ],
  "configurations": [
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          "negate": false,
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      "url": "https://git.kernel.org/stable/c/31ad74b20227ce6b40910ff78b1c604e42975cf1",
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