{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "68ef3bc3166468678d5e1fdd216628c35bd1186f"
            },
            {
              "fixed": "42d7954b0a1907d4ef122aef94561952a033cdc3"
            },
            {
              "fixed": "bb38ff8b4dafbbd1781ad37cd96722fdf2cd972a"
            },
            {
              "fixed": "b8bad5a11416b26cc7fd4b18fba46d75ff636558"
            },
            {
              "fixed": "1ce74d1b7770e69735e8f8e509807af4ff9c8ee7"
            },
            {
              "fixed": "a6ead6fff3a7d03e49845f048f7000a2e0d34431"
            },
            {
              "fixed": "4804c58f73a80d12df1de323bf97a164f6ee8743"
            },
            {
              "fixed": "8cf4ff0a7c083dd5e0067f517d63979b74b66649"
            },
            {
              "fixed": "5e2fa29d223a9a1e6a948e40b109d09081d1decd"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "e294c4c2d33b7307a89cdf31bec08a112d6a9297"
            },
            {
              "last_affected": "797bfd05d4040fbf766198b3cfcc1838002cc890"
            },
            {
              "last_affected": "0f44e9da465ea259b6c9f31a627f3c50a16e1679"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "4.9.91"
            },
            {
              "fixed": "4.10"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "4.14.31"
            },
            {
              "fixed": "4.15"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "4.15.14"
            },
            {
              "fixed": "4.16"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.16.0"
            },
            {
              "fixed": "5.10.270"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.221"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.188"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.157"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.109"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89662.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent lock owner use-after-free during client teardown\n\n__destroy_client() releases a client's open owners, but a lock owner\nwhose only reference is a blocked lock (nbl) stays on\ncl_ownerstr_hashtbl.  client_has_state() does not count a bare owner,\nso DESTROY_CLIENTID can reach __destroy_client() with such owners\npresent.\n\n__destroy_client() then walks the table, calling remove_blocked_locks()\non each owner without a reference.  Freeing a blocked lock drops the\nowner reference held via flc_owner.  The per-net laundromat reaps\nblocked locks from nn-\u003eblocked_locks_lru independently of client state.\nThe two paths share blocked_locks_lock only for the list splice, not\nthe owner's lifetime.  The laundromat therefore frees the owner as\n__destroy_client() dereferences it, a NULL dereference in\nremove_blocked_locks().\n\nnfsd4_release_lockowner() holds a reference across the same call;\n__destroy_client() does not.  Hold cl_lock across the walk, taking a\nreference and unhashing each owner, then drop it before\nremove_blocked_locks() and nfs4_put_stateowner(), which take\nblocked_locks_lock and cl_lock.",
  "id": "CVE-2026-89662",
  "modified": "2026-09-15T03:30:38.190734746Z",
  "published": "2026-09-11T19:45:49.833Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1ce74d1b7770e69735e8f8e509807af4ff9c8ee7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/42d7954b0a1907d4ef122aef94561952a033cdc3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4804c58f73a80d12df1de323bf97a164f6ee8743"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5e2fa29d223a9a1e6a948e40b109d09081d1decd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8cf4ff0a7c083dd5e0067f517d63979b74b66649"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a6ead6fff3a7d03e49845f048f7000a2e0d34431"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b8bad5a11416b26cc7fd4b18fba46d75ff636558"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/bb38ff8b4dafbbd1781ad37cd96722fdf2cd972a"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89662.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89662"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "NFSD: Prevent lock owner use-after-free during client teardown"
}