{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "c5c707f96fc9a6e5a57ca5baac892673270abe3d"
            },
            {
              "fixed": "c517f27498757e616d2a8fe6d16caad1fee422e6"
            },
            {
              "fixed": "607a56fea772c1f4f4989d8e255dd4f7192d9604"
            },
            {
              "fixed": "97bda8b4284d90897a1f1922e5082ff9e35d7c7e"
            },
            {
              "fixed": "ca94ba36172046be6a694a7986f6931e47ed4d51"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "4.0.0"
            },
            {
              "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-2026-89686.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix BUG_ON in nfsd4_alloc_layout_stateid on racing delegation revoke\n\nnfsd4_alloc_layout_stateid reads fp-\u003efi_deleg_file without holding\nfi_lock when the parent stateid is a delegation. A concurrent delegation\nrevoke via the laundromat can clear fi_deleg_file under fi_lock, causing\nnfsd_file_get() to return NULL and triggering the BUG_ON.\n\nThis race is client-reachable: two NFS clients can trigger it by having\none hold a delegation while another opens the same file to force a\nrecall. When the first client doesn't respond to the recall, the\nlaundromat revokes it. A concurrent LAYOUTGET from any client using the\ndelegation stateid hits the race window.\n\nFix this by taking fi_lock around the fi_deleg_file read in the\nSC_TYPE_DELEG path, matching the locking discipline of the\nfind_any_file() arm, and replacing the BUG_ON with a graceful error\nreturn that cleans up the partially-initialized layout stateid.",
  "id": "CVE-2026-89686",
  "modified": "2026-09-13T03:30:40.442305409Z",
  "published": "2026-09-11T19:46:07.877Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/607a56fea772c1f4f4989d8e255dd4f7192d9604"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/97bda8b4284d90897a1f1922e5082ff9e35d7c7e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c517f27498757e616d2a8fe6d16caad1fee422e6"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ca94ba36172046be6a694a7986f6931e47ed4d51"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89686.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89686"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "nfsd: fix BUG_ON in nfsd4_alloc_layout_stateid on racing delegation revoke"
}