fkie_cve-2025-38620
Vulnerability from fkie_nvd
Published
2025-08-22 16:15
Modified
2025-08-22 18:08
Severity ?
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/765761851d89c772f482494d452e266795460278
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c7c87046b41a9ef28ee7ac476c369da5b5228bc5
Impacted products
Vendor Product Version


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{
  "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": "2025-08-22T18:08:51.663",
  "metrics": {},
  "published": "2025-08-22T16:15:35.320",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/765761851d89c772f482494d452e266795460278"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c7c87046b41a9ef28ee7ac476c369da5b5228bc5"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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