{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  NFSD: Prevent lock owner use-after-free during client teardown  __destroy_client() releases a client's open owners, but a lock owner whose only reference is a blocked lock (nbl) stays on cl_ownerstr_hashtbl.  client_has_state() does not count a bare owner, so DESTROY_CLIENTID can reach __destroy_client() with such owners present.  __destroy_client() then walks the table, calling remove_blocked_locks() on each owner without a reference.  Freeing a blocked lock drops the owner reference held via flc_owner.  The per-net laundromat reaps blocked locks from nn-\u003eblocked_locks_lru independently of client state. The two paths share blocked_locks_lock only for the list splice, not the owner's lifetime.  The laundromat therefore frees the owner as __destroy_client() dereferences it, a NULL dereference in remove_blocked_locks().  nfsd4_release_lockowner() holds a reference across the same call; __destroy_client() does not.  Hold cl_lock across the walk, taking a reference and unhashing each owner, then drop it before remove_blocked_locks() and nfs4_put_stateowner(), which take blocked_locks_lock and cl_lock.",
  "id": "DEBIAN-CVE-2026-89662",
  "modified": "2026-09-15T08:47:28.994254354Z",
  "published": "2026-09-11T20:19:52.523Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-89662"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-89662"
  ]
}