CVE-2025-38620 (GCVE-0-2025-38620)
Vulnerability from cvelistv5
Published
2025-08-22 16:00
Modified
2025-08-22 16:00
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
Linux Linux Version: eb0570c7df23c2f32fe899fcdaf8fca9a5ecd51e
Version: eb0570c7df23c2f32fe899fcdaf8fca9a5ecd51e
 Create a notification for this product.
   Linux Linux Version: 6.16
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "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-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.16.1",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.17-rc1",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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)."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-08-22T16:00:24.445Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c7c87046b41a9ef28ee7ac476c369da5b5228bc5"
        },
        {
          "url": "https://git.kernel.org/stable/c/765761851d89c772f482494d452e266795460278"
        }
      ],
      "title": "zloop: fix KASAN use-after-free of tag set",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-38620",
    "datePublished": "2025-08-22T16:00:24.445Z",
    "dateReserved": "2025-04-16T04:51:24.029Z",
    "dateUpdated": "2025-08-22T16:00:24.445Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2025-38620\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-08-22T16:15:35.320\",\"lastModified\":\"2025-08-22T18:08:51.663\",\"vulnStatus\":\"Awaiting Analysis\",\"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).\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/765761851d89c772f482494d452e266795460278\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c7c87046b41a9ef28ee7ac476c369da5b5228bc5\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.