« Volver al listado

CVE-2026-89692

Estado: RecibidaAlta (7.5)—

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

nfsd: clear CALLBACK_RUNNING on failed delegation recall queue

nfsd_break_one_deleg() sets NFSD4_CALLBACK_RUNNING via test_and_set_bit at entry to serialize recall work, then calls nfsd4_run_cb() to queue the recall. When the queue attempt fails the refcount bump is undone, but the RUNNING bit is left set. The only site that clears the bit is nfsd41_destroy_cb() (fs/nfsd/nfs4callback.c), which runs from the workqueue and is therefore unreachable when nothing was queued.

The bit becomes a permanent latch on dp->dl_recall.cb_flags: every subsequent break_lease() on the same delegation hits the early-return guard in nfsd_break_one_deleg() and silently skips the recall, so the delegation is never broken and the conflicting open or lock stalls.

Leer descripción completaMostrar menos

Fix by clearing NFSD4_CALLBACK_RUNNING on the !queued branch alongside the refcount_dec.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

🎯 Técnicas ATT&CK

Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.

Inferido por reglas deterministas a partir del vector CVSS y la CWE. Solo orientativo.

🛡️ Mitigaciones ATT&CK que cubren estas técnicas

Filter Network TrafficVulnerability ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkApplication Isolation and Sandboxing

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Linux — Linux KernelAI

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2026-89692",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "1054e8ffc5c492f341bdf1888b882f1d163dd3d8",
              "lessThan": "b137930ee52e3ef38915a3511d4c070463b63a32",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1054e8ffc5c492f341bdf1888b882f1d163dd3d8",
              "lessThan": "cb2d0c4d1b3d301d042ed61365eaa8cb0141a254",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1054e8ffc5c492f341bdf1888b882f1d163dd3d8",
              "lessThan": "b036727d334b1b7cd4c1f1fba3b59ba93a6bbe96",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/nfsd/nfs4state.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.15",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.50",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.2.4",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/nfsd/nfs4state.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-11T20:19:56.260",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/b036727d334b1b7cd4c1f1fba3b59ba93a6bbe96",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b137930ee52e3ef38915a3511d4c070463b63a32",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/cb2d0c4d1b3d301d042ed61365eaa8cb0141a254",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: clear CALLBACK_RUNNING on failed delegation recall queue\n\nnfsd_break_one_deleg() sets NFSD4_CALLBACK_RUNNING via test_and_set_bit\nat entry to serialize recall work, then calls nfsd4_run_cb() to queue\nthe recall.  When the queue attempt fails the refcount bump is undone,\nbut the RUNNING bit is left set.  The only site that clears the bit is\nnfsd41_destroy_cb() (fs/nfsd/nfs4callback.c), which runs from the\nworkqueue and is therefore unreachable when nothing was queued.\n\nThe bit becomes a permanent latch on dp->dl_recall.cb_flags: every\nsubsequent break_lease() on the same delegation hits the early-return\nguard in nfsd_break_one_deleg() and silently skips the recall, so the\ndelegation is never broken and the conflicting open or lock stalls.\n\nFix by clearing NFSD4_CALLBACK_RUNNING on the !queued branch alongside\nthe refcount_dec."
    }
  ],
  "lastModified": "2026-09-13T07:17:35.107",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}