Vulnerability-Lookup

GHSA-P238-X8FG-RQHX

Vulnerability from github – Published: 2026-01-13 18:31 – Updated: 2026-01-13 18:31

Details

In the Linux kernel, the following vulnerability has been resolved:

nfsd: fix nfsd_file reference leak in nfsd4_add_rdaccess_to_wrdeleg()

nfsd4_add_rdaccess_to_wrdeleg() unconditionally overwrites fp->fi_fds[O_RDONLY] with a newly acquired nfsd_file. However, if the client already has a SHARE_ACCESS_READ open from a previous OPEN operation, this action overwrites the existing pointer without releasing its reference, orphaning the previous reference.

Additionally, the function originally stored the same nfsd_file pointer in both fp->fi_fds[O_RDONLY] and fp->fi_rdeleg_file with only a single reference. When put_deleg_file() runs, it clears fi_rdeleg_file and calls nfs4_file_put_access() to release the file.

However, nfs4_file_put_access() only releases fi_fds[O_RDONLY] when the fi_access[O_RDONLY] counter drops to zero. If another READ open exists on the file, the counter remains elevated and the nfsd_file reference from the delegation is never released. This potentially causes open conflicts on that file.

Then, on server shutdown, these leaks cause __nfsd_file_cache_purge() to encounter files with an elevated reference count that cannot be cleaned up, ultimately triggering a BUG() in kmem_cache_destroy() because there are still nfsd_file objects allocated in that cache.

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{
  "affected": [],
  "aliases": [
    "CVE-2025-71090"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-01-13T16:16:08Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix nfsd_file reference leak in nfsd4_add_rdaccess_to_wrdeleg()\n\nnfsd4_add_rdaccess_to_wrdeleg() unconditionally overwrites\nfp-\u003efi_fds[O_RDONLY] with a newly acquired nfsd_file. However, if\nthe client already has a SHARE_ACCESS_READ open from a previous OPEN\noperation, this action overwrites the existing pointer without\nreleasing its reference, orphaning the previous reference.\n\nAdditionally, the function originally stored the same nfsd_file\npointer in both fp-\u003efi_fds[O_RDONLY] and fp-\u003efi_rdeleg_file with\nonly a single reference. When put_deleg_file() runs, it clears\nfi_rdeleg_file and calls nfs4_file_put_access() to release the file.\n\nHowever, nfs4_file_put_access() only releases fi_fds[O_RDONLY] when\nthe fi_access[O_RDONLY] counter drops to zero. If another READ open\nexists on the file, the counter remains elevated and the nfsd_file\nreference from the delegation is never released. This potentially\ncauses open conflicts on that file.\n\nThen, on server shutdown, these leaks cause __nfsd_file_cache_purge()\nto encounter files with an elevated reference count that cannot be\ncleaned up, ultimately triggering a BUG() in kmem_cache_destroy()\nbecause there are still nfsd_file objects allocated in that cache.",
  "id": "GHSA-p238-x8fg-rqhx",
  "modified": "2026-01-13T18:31:06Z",
  "published": "2026-01-13T18:31:06Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-71090"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8072e34e1387d03102b788677d491e2bcceef6f5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c07dc84ed67c5a182273171639bacbbb87c12175"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2025-71090 (GCVE-0-2025-71090)

Vulnerability from cvelistv5 – Published: 2026-01-13 15:34 – Updated: 2026-01-13 15:34

Title

nfsd: fix nfsd_file reference leak in nfsd4_add_rdaccess_to_wrdeleg()

Summary

In the Linux kernel, the following vulnerability has been resolved: nfsd: fix nfsd_file reference leak in nfsd4_add_rdaccess_to_wrdeleg() nfsd4_add_rdaccess_to_wrdeleg() unconditionally overwrites fp->fi_fds[O_RDONLY] with a newly acquired nfsd_file. However, if the client already has a SHARE_ACCESS_READ open from a previous OPEN operation, this action overwrites the existing pointer without releasing its reference, orphaning the previous reference. Additionally, the function originally stored the same nfsd_file pointer in both fp->fi_fds[O_RDONLY] and fp->fi_rdeleg_file with only a single reference. When put_deleg_file() runs, it clears fi_rdeleg_file and calls nfs4_file_put_access() to release the file. However, nfs4_file_put_access() only releases fi_fds[O_RDONLY] when the fi_access[O_RDONLY] counter drops to zero. If another READ open exists on the file, the counter remains elevated and the nfsd_file reference from the delegation is never released. This potentially causes open conflicts on that file. Then, on server shutdown, these leaks cause __nfsd_file_cache_purge() to encounter files with an elevated reference count that cannot be cleaned up, ultimately triggering a BUG() in kmem_cache_destroy() because there are still nfsd_file objects allocated in that cache.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/c07dc84ed67c5a182…
	https://git.kernel.org/stable/c/8072e34e1387d0310…

Impacted products

Vendor

Product

Version

Linux

Affected: e7a8ebc305f26cab608e59a916a4ae89d6656c5f , < c07dc84ed67c5a182273171639bacbbb87c12175 (git)
Affected: e7a8ebc305f26cab608e59a916a4ae89d6656c5f , < 8072e34e1387d03102b788677d491e2bcceef6f5 (git)

Linux

Affected: 6.17
Unaffected: 0 , < 6.17 (semver)
Unaffected: 6.18.4 , ≤ 6.18.* (semver)
Unaffected: 6.19-rc4 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/nfs4state.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c07dc84ed67c5a182273171639bacbbb87c12175",
              "status": "affected",
              "version": "e7a8ebc305f26cab608e59a916a4ae89d6656c5f",
              "versionType": "git"
            },
            {
              "lessThan": "8072e34e1387d03102b788677d491e2bcceef6f5",
              "status": "affected",
              "version": "e7a8ebc305f26cab608e59a916a4ae89d6656c5f",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/nfsd/nfs4state.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.17"
            },
            {
              "lessThan": "6.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.19-rc4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.4",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.19-rc4",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix nfsd_file reference leak in nfsd4_add_rdaccess_to_wrdeleg()\n\nnfsd4_add_rdaccess_to_wrdeleg() unconditionally overwrites\nfp-\u003efi_fds[O_RDONLY] with a newly acquired nfsd_file. However, if\nthe client already has a SHARE_ACCESS_READ open from a previous OPEN\noperation, this action overwrites the existing pointer without\nreleasing its reference, orphaning the previous reference.\n\nAdditionally, the function originally stored the same nfsd_file\npointer in both fp-\u003efi_fds[O_RDONLY] and fp-\u003efi_rdeleg_file with\nonly a single reference. When put_deleg_file() runs, it clears\nfi_rdeleg_file and calls nfs4_file_put_access() to release the file.\n\nHowever, nfs4_file_put_access() only releases fi_fds[O_RDONLY] when\nthe fi_access[O_RDONLY] counter drops to zero. If another READ open\nexists on the file, the counter remains elevated and the nfsd_file\nreference from the delegation is never released. This potentially\ncauses open conflicts on that file.\n\nThen, on server shutdown, these leaks cause __nfsd_file_cache_purge()\nto encounter files with an elevated reference count that cannot be\ncleaned up, ultimately triggering a BUG() in kmem_cache_destroy()\nbecause there are still nfsd_file objects allocated in that cache."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-01-13T15:34:51.777Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c07dc84ed67c5a182273171639bacbbb87c12175"
        },
        {
          "url": "https://git.kernel.org/stable/c/8072e34e1387d03102b788677d491e2bcceef6f5"
        }
      ],
      "title": "nfsd: fix nfsd_file reference leak in nfsd4_add_rdaccess_to_wrdeleg()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2025-71090",
    "datePublished": "2026-01-13T15:34:51.777Z",
    "dateReserved": "2026-01-13T15:30:19.649Z",
    "dateUpdated": "2026-01-13T15:34:51.777Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-P238-X8FG-RQHX

CVE-2025-71090 (GCVE-0-2025-71090)

Tags

Sightings

Nomenclature