CVE-2026-68083

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix path resolution in ksmbd_vfs_kern_path_create The SMB2 open lookup is rooted at the share with LOOKUP_BENEATH, but the create/mkdir/hardlink sink is not: ksmbd_vfs_kern_path_create() builds an absolute path with convert_to_unix_name() and resolves it from AT_FDCWD via start_creating_path(), so a ".." component is walked from the real filesystem root and escapes the export. An authenticated client races a missing path component so the rooted open lookup returns -ENOENT (taking the create branch) while the same component is present (a directory) when the create walk runs; the create then resolves ".." out of the share. Root the create walk at the share like the lookup and rename paths already are: resolve the parent with vfs_path_parent_lookup(..., LOOKUP_BENEATH, &share_conf->vfs_path) and create the final component with start_creating_noperm(). convert_to_unix_name() then has no callers and is removed.

Severity

CRITICAL

CVSS score

9.1 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-08-10 12:17:20.807000

Last modified

2026-10-30 13:19:39.213000

View original CVE JSON

{
  "id": "CVE-2026-68083",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-10T12:17:20.807",
  "lastModified": "2026-10-30T13:19:39.213",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix path resolution in ksmbd_vfs_kern_path_create\n\nThe SMB2 open lookup is rooted at the share with LOOKUP_BENEATH, but the\ncreate/mkdir/hardlink sink is not: ksmbd_vfs_kern_path_create() builds an\nabsolute path with convert_to_unix_name() and resolves it from AT_FDCWD\nvia start_creating_path(), so a \"..\" component is walked from the real\nfilesystem root and escapes the export.\n\nAn authenticated client races a missing path component so the rooted open\nlookup returns -ENOENT (taking the create branch) while the same component\nis present (a directory) when the create walk runs; the create then\nresolves \"..\" out of the share.\n\nRoot the create walk at the share like the lookup and rename paths already\nare: resolve the parent with vfs_path_parent_lookup(..., LOOKUP_BENEATH,\n&share_conf->vfs_path) and create the final component with\nstart_creating_noperm(). convert_to_unix_name() then has no callers and is\nremoved."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/smb/server/misc.c",
            "fs/smb/server/misc.h",
            "fs/smb/server/vfs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "265fd1991c1db85fbabaad4946ca0e63e2ae688d",
              "lessThan": "f1f53dc95edfb3d2072e5e8cd8eb9a2fe7d7f2d0",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "265fd1991c1db85fbabaad4946ca0e63e2ae688d",
              "lessThan": "a2516be69048856e2a49a51e00975dc59431f95c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "265fd1991c1db85fbabaad4946ca0e63e2ae688d",
              "lessThan": "489d1ded01425c0fb33418172c0e4e588467526b",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "265fd1991c1db85fbabaad4946ca0e63e2ae688d",
              "lessThan": "c7c884a1305aa4540eb7942a50bd356b34120e1f",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "265fd1991c1db85fbabaad4946ca0e63e2ae688d",
              "lessThan": "98185b3025beeae92d1fe700d5db26b9ac4bf025",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "265fd1991c1db85fbabaad4946ca0e63e2ae688d",
              "lessThan": "1c8951963d8ed357f70f59e0ad4ddce2199d2016",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/smb/server/misc.c",
            "fs/smb/server/misc.h",
            "fs/smb/server/vfs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.15",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.15",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.97",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.40",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.5",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.2
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/1c8951963d8ed357f70f59e0ad4ddce2199d2016",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/489d1ded01425c0fb33418172c0e4e588467526b",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/98185b3025beeae92d1fe700d5db26b9ac4bf025",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a2516be69048856e2a49a51e00975dc59431f95c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c7c884a1305aa4540eb7942a50bd356b34120e1f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f1f53dc95edfb3d2072e5e8cd8eb9a2fe7d7f2d0",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}