FKIE_CVE-2025-38620

Vulnerability from fkie_nvd - Published: 2025-08-22 16:15 - Updated: 2026-06-17 09:17
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
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. zloop_ctl_remove() put_disk(zlo->disk) put_device() kobject_put() ... zloop_free_disk() kvfree(zlo) blk_mq_free_tag_set(&zlo->tag_set) 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).
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/765761851d89c772f482494d452e266795460278Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c7c87046b41a9ef28ee7ac476c369da5b5228bc5Patch
Impacted products
Vendor Product Version
linux linux_kernel 6.16
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/zloop.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c7c87046b41a9ef28ee7ac476c369da5b5228bc5",
              "status": "affected",
              "version": "eb0570c7df23c2f32fe899fcdaf8fca9a5ecd51e",
              "versionType": "git"
            },
            {
              "lessThan": "765761851d89c772f482494d452e266795460278",
              "status": "affected",
              "version": "eb0570c7df23c2f32fe899fcdaf8fca9a5ecd51e",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/block/zloop.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.16.*",
              "status": "unaffected",
              "version": "6.16.1",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.17",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:6.16:*:*:*:*:*:*:*",
              "matchCriteriaId": "D6BFC4F7-7099-4420-AF39-DD1CEABB8DF9",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "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(\u0026zlo-\u003etag_set), which accesses the freed zlo.\nHence the KASAN use-after-free.\n\n zloop_ctl_remove()\n  put_disk(zlo-\u003edisk)\n   put_device()\n    kobject_put()\n     ...\n      zloop_free_disk()\n        kvfree(zlo)\n  blk_mq_free_tag_set(\u0026zlo-\u003etag_set)\n\nTo avoid the BUG, move the call to blk_mq_free_tag_set(\u0026zlo-\u003etag_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: correcci\u00f3n del uso tras liberaci\u00f3n 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(\u0026amp;zlo-\u0026gt;tag_set), que accede al puntero zloop liberado. De ah\u00ed use-after-free de KASAN. Para evitar el error, mueva la llamada a blk_mq_free_tag_set(\u0026amp;zlo-\u0026gt;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)."
    }
  ],
  "id": "CVE-2025-38620",
  "lastModified": "2026-06-17T09:17:13.900",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2025-08-22T16:15:35.320",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/765761851d89c772f482494d452e266795460278"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c7c87046b41a9ef28ee7ac476c369da5b5228bc5"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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