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CVE-2026-89709

Estado: RecibidaAlta (8.1)—

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

lockd, nfsd: RCU-protect nlmsvc_ops dispatch

nlmsvc_ops is published by nfsd_lockd_init() and cleared by nfsd_lockd_shutdown() with plain stores, while lockd dereferences it unguarded from dispatch sites in fs/lockd/svcsubs.c. The pointer targets nfsd's .rodata and the fopen/fclose callbacks live in nfsd's .text, so a stale load after rmmod nfsd results in either a NULL deref or a module-text use-after-free.

Declare nlmsvc_ops as __rcu, publish via rcu_assign_pointer(), clear via RCU_INIT_POINTER() + synchronize_rcu().

Leer descripción completaMostrar menos

Add a struct module *owner field to nlmsvc_binding and pin the module across indirect calls with try_module_get/module_put. When the binding is torn down, fall back to fput() to avoid leaking struct file references.

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

Vulnerability ScanningPrivileged Account ManagementNetwork SegmentationLimit Access to Resource Over NetworkFilter Network TrafficApplication 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)

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{
  "id": "CVE-2026-89709",
  "cveTags": [],
  "metrics": {
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 8.1,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 2.2
      }
    ]
  },
  "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": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "3c461a1820088fb5889d73a6522369bde45527a9",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "lessThan": "641e5e20852359b8c31149be4598884e30652f60",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "fs/lockd/svc.c",
            "fs/lockd/svc4proc.c",
            "fs/lockd/svcproc.c",
            "fs/lockd/svcsubs.c",
            "fs/nfsd/lockd.c",
            "include/linux/lockd/bind.h"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "2.6.12",
              "versionType": "semver"
            },
            {
              "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/lockd/svc.c",
            "fs/lockd/svc4proc.c",
            "fs/lockd/svcproc.c",
            "fs/lockd/svcsubs.c",
            "fs/nfsd/lockd.c",
            "include/linux/lockd/bind.h"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-09-11T20:19:58.270",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/3c461a1820088fb5889d73a6522369bde45527a9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/641e5e20852359b8c31149be4598884e30652f60",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlockd, nfsd: RCU-protect nlmsvc_ops dispatch\n\nnlmsvc_ops is published by nfsd_lockd_init() and cleared by\nnfsd_lockd_shutdown() with plain stores, while lockd dereferences\nit unguarded from dispatch sites in fs/lockd/svcsubs.c. The pointer\ntargets nfsd's .rodata and the fopen/fclose callbacks live in nfsd's\n.text, so a stale load after rmmod nfsd results in either a NULL\nderef or a module-text use-after-free.\n\nDeclare nlmsvc_ops as __rcu, publish via rcu_assign_pointer(), clear\nvia RCU_INIT_POINTER() + synchronize_rcu(). Add a struct module\n*owner field to nlmsvc_binding and pin the module across indirect\ncalls with try_module_get/module_put. When the binding is torn down,\nfall back to fput() to avoid leaking struct file references."
    }
  ],
  "lastModified": "2026-09-13T07:17:36.617",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}