FKIE_CVE-2026-90236

Vulnerability from fkie_nvd - Published: 2026-09-17 17:17 - Updated: 2026-09-17 17:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: NFSD: Release the export reference when reaping open stateids nfs4_put_stid() releases the svc_export tracked in nfs4_stid.sc_export, but free_ol_stateid_reaplist() frees open and lock stateids by calling ->sc_free() directly, bypassing that path. An open stateid takes an sc_export reference in nfs4_open() and a lock stateid takes its own in init_lock_stateid(); both reach free_ol_stateid_reaplist() through their normal teardown, the open stateid via release_open_stateid() and the lock stateid via nfsd4_release_lockowner(), each through put_ol_stateid_locked(). The reference is therefore never dropped, pinning the export and blocking unmount for the lifetime of the stateid. Release sc_export in free_ol_stateid_reaplist() the way nfs4_put_stid() does. ->sc_free() runs once per stateid, and a stateid reaches free_ol_stateid_reaplist() or nfs4_put_stid() but never both, so the reference is dropped exactly once. Revoked stateids reach this path with sc_export already cleared by drop_stid_export(), so they are skipped rather than double-freed. nfs4_put_stid() itself read sc_export before acquiring cl_lock. drop_stid_export() clears that field and releases the reference under cl_lock, so a concurrent revocation could drop the export in the window between the read and the final put, releasing the same reference twice. Read sc_export while cl_lock is held so the two paths serialize and the reference is released exactly once.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6480bd703684ed3f760e9e36c4a699033c0806ae
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7458727fd7cb79d09e5120b6fecc1ad11cdb0946
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "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": "7458727fd7cb79d09e5120b6fecc1ad11cdb0946",
              "status": "affected",
              "version": "ba0cde5dc81d214684b8ea0bd87414ba2f48fe02",
              "versionType": "git"
            },
            {
              "lessThan": "6480bd703684ed3f760e9e36c4a699033c0806ae",
              "status": "affected",
              "version": "ba0cde5dc81d214684b8ea0bd87414ba2f48fe02",
              "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": "7.2"
            },
            {
              "lessThan": "7.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "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\nNFSD: Release the export reference when reaping open stateids\n\nnfs4_put_stid() releases the svc_export tracked in\nnfs4_stid.sc_export, but free_ol_stateid_reaplist() frees open and\nlock stateids by calling -\u003esc_free() directly, bypassing that path.\nAn open stateid takes an sc_export reference in nfs4_open() and a\nlock stateid takes its own in init_lock_stateid(); both reach\nfree_ol_stateid_reaplist() through their normal teardown, the open\nstateid via release_open_stateid() and the lock stateid via\nnfsd4_release_lockowner(), each through put_ol_stateid_locked().\nThe reference is therefore never dropped, pinning the export and\nblocking unmount for the lifetime of the stateid.\n\nRelease sc_export in free_ol_stateid_reaplist() the way\nnfs4_put_stid() does. -\u003esc_free() runs once per stateid, and a\nstateid reaches free_ol_stateid_reaplist() or nfs4_put_stid() but\nnever both, so the reference is dropped exactly once. Revoked\nstateids reach this path with sc_export already cleared by\ndrop_stid_export(), so they are skipped rather than double-freed.\n\nnfs4_put_stid() itself read sc_export before acquiring cl_lock.\ndrop_stid_export() clears that field and releases the reference\nunder cl_lock, so a concurrent revocation could drop the export in\nthe window between the read and the final put, releasing the same\nreference twice. Read sc_export while cl_lock is held so the two\npaths serialize and the reference is released exactly once."
    }
  ],
  "id": "CVE-2026-90236",
  "lastModified": "2026-09-17T17:17:19.533",
  "metrics": {},
  "published": "2026-09-17T17:17:19.533",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6480bd703684ed3f760e9e36c4a699033c0806ae"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7458727fd7cb79d09e5120b6fecc1ad11cdb0946"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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