FKIE_CVE-2026-53244

Vulnerability from fkie_nvd - Published: 2026-06-25 09:16 - Updated: 2026-06-30 14:44
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: VFS: fix possible failure to unlock in nfsd4_create_file() atomic_create() in fs/namei.c drops the reference to the dentry when it returns an error. This behaviour was imported into dentry_create() so that it will drop the reference if an error is returned from atomic_create(), though not if vfs_create() returns an error (in the case where ->atomic_create is not supported). The caller - nfsd4_create_file() - is made aware of this by checking path->dentry, which will either be a counted reference to a dentry, or an error pointer. However the change to use start_creating()/end_creating() (which landed shortly before the dentry_create() change landed, though was likely developed around the same time) means that nfsd4_create_file() *needs* a valid dentry so that it can unlock the parent. The net result is that if NFSD exports a filesystem which uses ->atomic_create, and if a call to ->atomic_create returns an error, then nfsd4_create_file() will pass an error pointer to end_creating() and the parent will not be unlocked. Fix this by changing dentry_create() to make sure path->dentry is always a valid dentry, never an error-pointer. The actual error is already returned a different way. Note that if ->atomic_create() returns a different dentry (which may not be possible in practice) we are guaranteed (because it is only ever provided by d_spliace_alias()) that it will have the same d_parent and so it will have the same effect when passed to end_creating().
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e824bbd4d224cce4b5fb59cc9dcd3447fe0b7e44
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ee1f40759a50b1800c98c1c369afd5b3e44ad987
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/namei.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ee1f40759a50b1800c98c1c369afd5b3e44ad987",
              "status": "affected",
              "version": "64a989dbd144e0622371396461b11335459692d2",
              "versionType": "git"
            },
            {
              "lessThan": "e824bbd4d224cce4b5fb59cc9dcd3447fe0b7e44",
              "status": "affected",
              "version": "64a989dbd144e0622371396461b11335459692d2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/namei.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.0"
            },
            {
              "lessThan": "7.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "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\nVFS: fix possible failure to unlock in nfsd4_create_file()\n\natomic_create() in fs/namei.c drops the reference to the dentry\nwhen it returns an error.\nThis behaviour was imported into dentry_create() so that it\nwill drop the reference if an error is returned from atomic_create(),\nthough not if vfs_create() returns an error (in the case where\n-\u003eatomic_create is not supported).\n\nThe caller - nfsd4_create_file() - is made aware of this by checking\npath-\u003edentry, which will either be a counted reference to a dentry, or\nan error pointer.\n\nHowever the change to use start_creating()/end_creating() (which landed\nshortly before the dentry_create() change landed, though was likely\ndeveloped around the same time) means that nfsd4_create_file() *needs* a\nvalid dentry so that it can unlock the parent.\n\nThe net result is that if NFSD exports a filesystem which uses\n-\u003eatomic_create, and if a call to -\u003eatomic_create returns an error, then\nnfsd4_create_file() will pass an error pointer to end_creating()\nand the parent will not be unlocked.\n\nFix this by changing dentry_create() to make sure path-\u003edentry is always\na valid dentry, never an error-pointer.  The actual error is already\nreturned a different way.\n\nNote that if -\u003eatomic_create() returns a different dentry (which may not\nbe possible in practice) we are guaranteed (because it is only ever\nprovided by d_spliace_alias()) that it will have the same d_parent and\nso it will have the same effect when passed to end_creating()."
    }
  ],
  "id": "CVE-2026-53244",
  "lastModified": "2026-06-30T14:44:27.313",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-06-25T09:16:42.350",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e824bbd4d224cce4b5fb59cc9dcd3447fe0b7e44"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ee1f40759a50b1800c98c1c369afd5b3e44ad987"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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