{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7919d0a27f1e7cb324e023776aa1cbff00f1ee7b"
            },
            {
              "fixed": "cd489b03587378645fe0d20142a33f1ed60bac98"
            },
            {
              "fixed": "6fedb2eaff77554ca7a0deffd2e8bc0d6e8b38b0"
            },
            {
              "fixed": "9026932ac8be4d0ae01db47f23619a98cc57b671"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.9.0"
            },
            {
              "fixed": "6.18.51"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90036.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: Prevent client use-after-free during blocked-lock reaping\n\nA bare lock owner -- its only remaining reference a blocked lock on\nnn-\u003eblocked_locks_lru -- holds a raw pointer to its nfs4_client but\nno reference keeping the client alive. When the per-net laundromat\nreaps such a lock, freeing the nbl drops the owner reference\nheld through flc_owner, and the final nfs4_put_stateowner()\ntakes the client's cl_lock. Because the laundromat detaches the\nnbl first, __destroy_client() no longer finds it, so a concurrent\nforce_expire_client() can free the client before nfs4_put_stateowner()\nruns, dereferencing cl_lock in freed memory.\n\nPin the client with cl_rpc_users before dropping\nnn-\u003eblocked_locks_lock, and skip clients already expiring, whose\nblocked locks __destroy_client() frees while holding an owner\nreference. Take nn-\u003eclient_lock outside nn-\u003eblocked_locks_lock.\nEvery other site holds nn-\u003eblocked_locks_lock as a leaf, acquiring\nno further lock, so placing nn-\u003eclient_lock outside it cannot form\na lock-order cycle.",
  "id": "CVE-2026-90036",
  "modified": "2026-09-18T03:30:20.326567003Z",
  "published": "2026-09-16T10:33:35.967Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6fedb2eaff77554ca7a0deffd2e8bc0d6e8b38b0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9026932ac8be4d0ae01db47f23619a98cc57b671"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cd489b03587378645fe0d20142a33f1ed60bac98"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90036.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90036"
    },
    {
      "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 client use-after-free during blocked-lock reaping"
}