FKIE_CVE-2026-93827

Vulnerability from fkie_nvd - Published: 2026-09-24 17:17 - Updated: 2026-09-25 13:17
Severity
8.4 (High) - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: virtio-fs: avoid double-free on failed queue setup virtio_fs_setup_vqs() allocates fs->vqs and fs->mq_map before calling virtio_find_vqs(). If virtio_find_vqs() fails, the error path frees both pointers and returns an error to virtio_fs_probe(). virtio_fs_probe() then drops the last kobject reference, and virtio_fs_ktype_release() frees fs->vqs and fs->mq_map again. This leaves dangling pointers in struct virtio_fs and can trigger a double-free during probe failure cleanup. Set fs->vqs and fs->mq_map to NULL immediately after kfree() in the virtio_fs_setup_vqs() error path so that the later kobject release sees an uninitialized state and kfree(NULL) becomes harmless. This can be reproduced when a broken virtio-fs device advertises more request queues than the transport actually provides. In that case virtio_find_vqs() fails while setting up the extra queue, and the probe path reaches the double-free cleanup sequence.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/20ef4739b329bb09cff11dd2458795a50674658e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3fbc5ee776fefbc6ea34d2518f1f5f90aa2e1dad
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6af3330ec5d5fb8c06c04eb520a71cf73ea5a765
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/virtio_fs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "3fbc5ee776fefbc6ea34d2518f1f5f90aa2e1dad",
              "status": "affected",
              "version": "a8f62f50b4e4ea92a938fca2ec1bd108d7f210e9",
              "versionType": "git"
            },
            {
              "lessThan": "20ef4739b329bb09cff11dd2458795a50674658e",
              "status": "affected",
              "version": "a8f62f50b4e4ea92a938fca2ec1bd108d7f210e9",
              "versionType": "git"
            },
            {
              "lessThan": "6af3330ec5d5fb8c06c04eb520a71cf73ea5a765",
              "status": "affected",
              "version": "a8f62f50b4e4ea92a938fca2ec1bd108d7f210e9",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/fuse/virtio_fs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.9"
            },
            {
              "lessThan": "6.9",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio-fs: avoid double-free on failed queue setup\n\nvirtio_fs_setup_vqs() allocates fs-\u003evqs and fs-\u003emq_map before calling\nvirtio_find_vqs(). If virtio_find_vqs() fails, the error path frees both\npointers and returns an error to virtio_fs_probe().\n\nvirtio_fs_probe() then drops the last kobject reference, and\nvirtio_fs_ktype_release() frees fs-\u003evqs and fs-\u003emq_map again. This leaves\ndangling pointers in struct virtio_fs and can trigger a double-free during\nprobe failure cleanup.\n\nSet fs-\u003evqs and fs-\u003emq_map to NULL immediately after kfree() in the\nvirtio_fs_setup_vqs() error path so that the later kobject release sees an\nuninitialized state and kfree(NULL) becomes harmless.\n\nThis can be reproduced when a broken virtio-fs device advertises more\nrequest queues than the transport actually provides. In that case\nvirtio_find_vqs() fails while setting up the extra queue, and the probe\npath reaches the double-free cleanup sequence."
    }
  ],
  "id": "CVE-2026-93827",
  "lastModified": "2026-09-25T13:17:23.513",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 8.4,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-24T17:17:16.410",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/20ef4739b329bb09cff11dd2458795a50674658e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3fbc5ee776fefbc6ea34d2518f1f5f90aa2e1dad"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6af3330ec5d5fb8c06c04eb520a71cf73ea5a765"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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