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FKIE_CVE-2026-64399

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-09-04 14:46
Severity
9.8 (Critical) - CVSS:3.1/AV:N/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: ksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE The FSCTL_DUPLICATE_EXTENTS_TO_FILE arm of smb2_ioctl() overwrites the destination file's data via vfs_clone_file_range() with neither the share-level KSMBD_TREE_CONN_FLAG_WRITABLE check nor a per-handle fp->daccess check that the other write-bearing arms carry. A client can overwrite destination data on a read-only share, or from a handle opened with only FILE_WRITE_ATTRIBUTES (which still yields an FMODE_WRITE filp). FILE_WRITE_ATTRIBUTES-only destination handle overwrote the file's data via the clone. Add both checks, matching the FSCTL_SET_SPARSE permission fix; require FILE_WRITE_DATA since this writes data.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/388e4139db27a9e3612c9d356b826f5b1ff6a9e3Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/620d133d469295ee7c017ca6aafac335f65c4a5aPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9b9cf7e65cbeaae1b6636144bacee611cdd7a5d6Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/baae7b39673ec21073a25e3d14f8feaada01d5dfPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/bf460ad5958d506492de4524a656439da3f99c51Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c917e4522d251071dde9871b9142d8ea1186ebfePatch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "bf460ad5958d506492de4524a656439da3f99c51",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
              "lessThan": "620d133d469295ee7c017ca6aafac335f65c4a5a",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
              "lessThan": "9b9cf7e65cbeaae1b6636144bacee611cdd7a5d6",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
              "lessThan": "baae7b39673ec21073a25e3d14f8feaada01d5df",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
              "lessThan": "c917e4522d251071dde9871b9142d8ea1186ebfe",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            },
            {
              "lessThan": "388e4139db27a9e3612c9d356b826f5b1ff6a9e3",
              "status": "affected",
              "version": "eb817368f50c1cbe1bd07044124aad7db6330e3a",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/smb/server/smb2pdu.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.15"
            },
            {
              "lessThan": "5.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "489A511C-ECAA-4ACC-BE73-C261B3681C52",
              "versionEndExcluding": "6.1.178",
              "versionStartIncluding": "5.15",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "7046B092-F810-4440-ACE6-60218518EECE",
              "versionEndExcluding": "6.6.145",
              "versionStartIncluding": "6.2",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "38A8100E-2B1A-462F-AEE9-8901B870FEF2",
              "versionEndExcluding": "6.12.96",
              "versionStartIncluding": "6.7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "914AE4BC-3D59-4C5A-9DB5-9CE327B429F7",
              "versionEndExcluding": "6.18.39",
              "versionStartIncluding": "6.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6228DDD6-4557-4AA3-9F43-AB995D471E42",
              "versionEndExcluding": "7.1.4",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: add permission checks for FSCTL_DUPLICATE_EXTENTS_TO_FILE\n\nThe FSCTL_DUPLICATE_EXTENTS_TO_FILE arm of smb2_ioctl() overwrites the\ndestination file\u0027s data via vfs_clone_file_range() with neither the\nshare-level KSMBD_TREE_CONN_FLAG_WRITABLE check nor a per-handle\nfp-\u003edaccess check that the other write-bearing arms carry. A client can\noverwrite destination data on a read-only share, or from a handle opened\nwith only FILE_WRITE_ATTRIBUTES (which still yields an FMODE_WRITE filp).\nFILE_WRITE_ATTRIBUTES-only destination handle overwrote the file\u0027s data via\nthe clone. Add both checks, matching the FSCTL_SET_SPARSE permission fix;\nrequire FILE_WRITE_DATA since this writes data."
    }
  ],
  "id": "CVE-2026-64399",
  "lastModified": "2026-09-04T14:46:44.060",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-25T10:17:23.397",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/388e4139db27a9e3612c9d356b826f5b1ff6a9e3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/620d133d469295ee7c017ca6aafac335f65c4a5a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/9b9cf7e65cbeaae1b6636144bacee611cdd7a5d6"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/baae7b39673ec21073a25e3d14f8feaada01d5df"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/bf460ad5958d506492de4524a656439da3f99c51"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c917e4522d251071dde9871b9142d8ea1186ebfe"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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