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FKIE_CVE-2026-89560

Vulnerability from fkie_nvd - Published: 2026-09-11 20:19 - Updated: 2026-09-14 13:19
Severity
8.4 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: landlock: Require LANDLOCK_ACCESS_FS_MAKE_REG for whiteout creation Whiteout objects are used in the upper layer of an OverlayFS to indicate that the file with this name does not exist in the unified view, even if it is present in one of the lower layer file systems. For the userspace implementations of OverlayFS (fuse-overlayfs), whiteout objects can be created from userspace as well: * mknod(2) with S_IFCHR and makedev(0, 0) * renameat2(2) with RENAME_WHITEOUT, creating the whiteout in the old place of the moved file. This commit guards whiteout creation in both of these cases with LANDLOCK_ACCESS_FS_MAKE_REG. Whiteout objects are *not* considered character devices and are not bound to a driver. LANDLOCK_ACCESS_FS_MAKE_REG describes the same permission class as a whiteout object: creating one is the only S_IFCHR creation that the VFS exempts from CAP_MKNOD, so it is as unprivileged as creating a regular file, while LANDLOCK_ACCESS_FS_MAKE_CHAR and LANDLOCK_ACCESS_FS_MAKE_BLOCK keep meaning the creation of devices that expose a kernel interface [1]. For the mknod(2) case, introduce a Landlock erratum. The creation of whiteout objects through mknod(2) was previously guarded using LANDLOCK_ACCESS_FS_MAKE_CHAR, and it is now guarded using LANDLOCK_ACCESS_FS_MAKE_REG. For the renameat2(2) case, fix a bug: Before this commit, renameat2(2) with RENAME_WHITEOUT would create a directory entry even when all LANDLOCK_ACCESS_FS_MAKE_* rights were denied. This does not affect normal renames within layered OverlayFS mounts: When doing a regular rename() on a mounted fuse-overlayfs, it is the fuse-overlayfs daemon that exercises renameat2() with RENAME_WHITEOUT, and only the Landlock domain of that daemon is checked there. Depends-on: 49c9e09d9610 ("landlock: Fix handling of disconnected directories") Depends-on: fe72ce6710cb ("landlock: Add errata documentation section") [mic: Record why LANDLOCK_ACCESS_FS_MAKE_REG is the matching right, and add link(2) to the user doc]
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/0c3204aacbe8c07f9e87e3028f28ec6c166a1075
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/627ce4902df1d737e99306daae5a87c68b876d16
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/672fa082d48b21e1fb62cdb184fee41513e53421
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/d739e32318479086efb8a6bcf5d37cf341b51f8f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/dfb10d989056181168ebc16781a8f39520e33200
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/efb4f24fc2b9bcef1c41ff3392894f1fa8fba2a0
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/uapi/linux/landlock.h",
            "security/landlock/errata/abi-1.h",
            "security/landlock/fs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "d739e32318479086efb8a6bcf5d37cf341b51f8f",
              "status": "affected",
              "version": "cb2c7d1a1776057c9a1f48ed1250d85e94d4850d",
              "versionType": "git"
            },
            {
              "lessThan": "dfb10d989056181168ebc16781a8f39520e33200",
              "status": "affected",
              "version": "cb2c7d1a1776057c9a1f48ed1250d85e94d4850d",
              "versionType": "git"
            },
            {
              "lessThan": "efb4f24fc2b9bcef1c41ff3392894f1fa8fba2a0",
              "status": "affected",
              "version": "cb2c7d1a1776057c9a1f48ed1250d85e94d4850d",
              "versionType": "git"
            },
            {
              "lessThan": "627ce4902df1d737e99306daae5a87c68b876d16",
              "status": "affected",
              "version": "cb2c7d1a1776057c9a1f48ed1250d85e94d4850d",
              "versionType": "git"
            },
            {
              "lessThan": "0c3204aacbe8c07f9e87e3028f28ec6c166a1075",
              "status": "affected",
              "version": "cb2c7d1a1776057c9a1f48ed1250d85e94d4850d",
              "versionType": "git"
            },
            {
              "lessThan": "672fa082d48b21e1fb62cdb184fee41513e53421",
              "status": "affected",
              "version": "cb2c7d1a1776057c9a1f48ed1250d85e94d4850d",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/uapi/linux/landlock.h",
            "security/landlock/errata/abi-1.h",
            "security/landlock/fs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.13"
            },
            {
              "lessThan": "5.13",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.188",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.157",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.110",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "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\nlandlock: Require LANDLOCK_ACCESS_FS_MAKE_REG for whiteout creation\n\nWhiteout objects are used in the upper layer of an OverlayFS to\nindicate that the file with this name does not exist in the unified\nview, even if it is present in one of the lower layer file systems.\n\nFor the userspace implementations of OverlayFS (fuse-overlayfs),\nwhiteout objects can be created from userspace as well:\n\n* mknod(2) with S_IFCHR and makedev(0, 0)\n* renameat2(2) with RENAME_WHITEOUT,\n  creating the whiteout in the old place of the moved file.\n\nThis commit guards whiteout creation in both of these cases with\nLANDLOCK_ACCESS_FS_MAKE_REG.  Whiteout objects are *not* considered\ncharacter devices and are not bound to a driver.\n\nLANDLOCK_ACCESS_FS_MAKE_REG describes the same permission class as a\nwhiteout object: creating one is the only S_IFCHR creation that the VFS\nexempts from CAP_MKNOD, so it is as unprivileged as creating a regular\nfile, while LANDLOCK_ACCESS_FS_MAKE_CHAR and\nLANDLOCK_ACCESS_FS_MAKE_BLOCK keep meaning the creation of devices that\nexpose a kernel interface [1].\n\nFor the mknod(2) case, introduce a Landlock erratum.  The creation of\nwhiteout objects through mknod(2) was previously guarded using\nLANDLOCK_ACCESS_FS_MAKE_CHAR, and it is now guarded using\nLANDLOCK_ACCESS_FS_MAKE_REG.\n\nFor the renameat2(2) case, fix a bug: Before this commit, renameat2(2)\nwith RENAME_WHITEOUT would create a directory entry even when all\nLANDLOCK_ACCESS_FS_MAKE_* rights were denied.\n\nThis does not affect normal renames within layered OverlayFS mounts:\nWhen doing a regular rename() on a mounted fuse-overlayfs, it is the\nfuse-overlayfs daemon that exercises renameat2() with RENAME_WHITEOUT,\nand only the Landlock domain of that daemon is checked there.\n\nDepends-on: 49c9e09d9610 (\"landlock: Fix handling of disconnected directories\")\nDepends-on: fe72ce6710cb (\"landlock: Add errata documentation section\")\n[mic: Record why LANDLOCK_ACCESS_FS_MAKE_REG is the matching right, and\nadd link(2) to the user doc]"
    }
  ],
  "id": "CVE-2026-89560",
  "lastModified": "2026-09-14T13:19:11.093",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 8.4,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.0,
        "impactScore": 5.8,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-09-11T20:19:39.803",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0c3204aacbe8c07f9e87e3028f28ec6c166a1075"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/627ce4902df1d737e99306daae5a87c68b876d16"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/672fa082d48b21e1fb62cdb184fee41513e53421"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d739e32318479086efb8a6bcf5d37cf341b51f8f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/dfb10d989056181168ebc16781a8f39520e33200"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/efb4f24fc2b9bcef1c41ff3392894f1fa8fba2a0"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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