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CVE-2025-38620

Estado: AnalizadaAlta (7.8)—

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

zloop: fix KASAN use-after-free of tag set

When a zoned loop device, or zloop device, is removed, KASAN enabled kernel reports "BUG KASAN use-after-free" in blk_mq_free_tag_set(). The BUG happens because zloop_ctl_remove() calls put_disk(), which invokes zloop_free_disk(). The zloop_free_disk() frees the memory allocated for the zlo pointer. However, after the memory is freed, zloop_ctl_remove() calls blk_mq_free_tag_set(&zlo->tag_set), which accesses the freed zlo. Hence the KASAN use-after-free.

To avoid the BUG, move the call to blk_mq_free_tag_set(&zlo->tag_set) from zloop_ctl_remove() into zloop_free_disk(). This ensures that the tag_set is freed before the call to kvfree(zlo).

Detalles técnicos trazas, registros y código del informe original
 zloop_ctl_remove()
  put_disk(zlo->disk)
   put_device()
    kobject_put()
     ...
      zloop_free_disk()
        kvfree(zlo)
  blk_mq_free_tag_set(&zlo->tag_set)

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 use-after-free (CWE-416) en kernel Linux con acceso local (AV:L) y privilegios requeridos (PR:L). Permite escalada de privilegios o ejecución de código arbitrario mediante manipulación de la liberación de memoria en dispositivos zloop.

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 ContentPrivileged Account ManagementLimit Software InstallationBehavior Prevention on Endpoint

Tecnologías afectadas (1)

Linux — Linux Kernel

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2025-38620",
  "cveTags": [],
  "metrics": {
    "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
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  "affected": [
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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              "lessThan": "c7c87046b41a9ef28ee7ac476c369da5b5228bc5",
              "versionType": "git"
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          "defaultStatus": "unaffected"
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          "versions": [
            {
              "status": "affected",
              "version": "6.16"
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              "status": "unaffected",
              "version": "0",
              "lessThan": "6.16",
              "versionType": "semver"
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              "status": "unaffected",
              "version": "6.16.1",
              "versionType": "semver",
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              "status": "unaffected",
              "version": "6.17",
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              "lessThanOrEqual": "*"
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          "programFiles": [
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  "published": "2025-08-22T16:15:35.320",
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      "url": "https://git.kernel.org/stable/c/765761851d89c772f482494d452e266795460278",
      "tags": [
        "Patch"
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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  "vulnStatus": "Analyzed",
  "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\nzloop: fix KASAN use-after-free of tag set\n\nWhen a zoned loop device, or zloop device, is removed, KASAN enabled\nkernel reports \"BUG KASAN use-after-free\" in blk_mq_free_tag_set(). The\nBUG happens because zloop_ctl_remove() calls put_disk(), which invokes\nzloop_free_disk(). The zloop_free_disk() frees the memory allocated for\nthe zlo pointer. However, after the memory is freed, zloop_ctl_remove()\ncalls blk_mq_free_tag_set(&zlo->tag_set), which accesses the freed zlo.\nHence the KASAN use-after-free.\n\n zloop_ctl_remove()\n  put_disk(zlo->disk)\n   put_device()\n    kobject_put()\n     ...\n      zloop_free_disk()\n        kvfree(zlo)\n  blk_mq_free_tag_set(&zlo->tag_set)\n\nTo avoid the BUG, move the call to blk_mq_free_tag_set(&zlo->tag_set)\nfrom zloop_ctl_remove() into zloop_free_disk(). This ensures that\nthe tag_set is freed before the call to kvfree(zlo)."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: zloop: corrección del uso tras liberación de KASAN del conjunto de etiquetas. Al eliminar un dispositivo de bucle zonificado o un dispositivo zloop, el kernel habilitado para KASAN informa \"BUG KASAN use after-free\" en blk_mq_free_tag_set(). El error se produce porque zloop_ctl_remove() llama a put_disk(), que a su vez invoca zloop_free_disk(). zloop_free_disk() libera la memoria asignada al puntero zloop. Sin embargo, una vez liberada la memoria, zloop_ctl_remove() llama a blk_mq_free_tag_set(&zlo->tag_set), que accede al puntero zloop liberado. De ahí use-after-free de KASAN. Para evitar el error, mueva la llamada a blk_mq_free_tag_set(&zlo->tag_set) de zloop_ctl_remove() a zloop_free_disk(). Esto garantiza que el conjunto de etiquetas se libere antes de la llamada a kvfree(zlo)."
    }
  ],
  "lastModified": "2026-06-17T09:17:13.900",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D6BFC4F7-7099-4420-AF39-DD1CEABB8DF9"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}