{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "a4bc287943f5695209ff36bdc89f17b48d68fae7"
            },
            {
              "fixed": "2b59029b8f24a99b5d844af2da3950d39d36eeea"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "f4e44b393389c77958f7c58bf4415032b4cda15b"
            },
            {
              "fixed": "d9e151fea5ed706c1284adacabd869b0be745db2"
            },
            {
              "fixed": "659ee3da073164e1e6e40dfcbc26eeed85845f93"
            },
            {
              "fixed": "60680ae7243b22de3d09be990d8e23bcfc4af837"
            },
            {
              "fixed": "77de363d9a1c8cd35f20482782c612cda085791a"
            },
            {
              "fixed": "4ed8d2317aef21cc2a9e5a55d6b59860b4b151a8"
            },
            {
              "fixed": "7377fa964b8aaf47cb04e5efcc4c82d15e8c2ce9"
            },
            {
              "fixed": "036c1b182f4da65363e79ec0ac276edc6b7296e5"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.10.220"
            },
            {
              "fixed": "5.10.270"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.10.270"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.221"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.14.0"
            },
            {
              "fixed": "6.1.188"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.6.157"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.12.109"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "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-2026-89712.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSD: restart ssc_expire_umount walk after dropping nfsd_ssc_lock\n\nnfsd4_ssc_expire_umount() walks nn-\u003enfsd_ssc_mount_list with\nlist_for_each_entry_safe(ni, tmp, ...).  For each expired entry it\nsets nsui_busy = true, drops nfsd_ssc_lock to run mntput() on the\nsource vfsmount, then reacquires the lock to list_del + kfree the\nentry and continue iterating via the macro's saved tmp pointer.\n\nThe nsui_busy flag protects the current ni from concurrent\nnfsd4_ssc_setup_dul() finders during the lock-drop window, but it\ndoes not pin tmp.  Another nfsd RPC thread that fails its source-\nserver mount and reaches nfsd4_ssc_cancel_dul() will, during that\nsame window, take nfsd_ssc_lock, list_del + kfree its own ssc_umount\nitem, and release the lock.  If that item is the saved tmp of the\nexpire walk, the next iteration dereferences a freed\nnfsd4_ssc_umount_item.\n\nRestart the walk from the head after the mntput() unlock window so\nno saved next pointer survives the lock-drop.  The list is bounded\nby the number of active inter-server source mounts (typically small)\nand the expire delayed-work runs periodically rather than per-IO,\nso the restart is cheap.",
  "id": "CVE-2026-89712",
  "modified": "2026-09-15T03:30:45.568772699Z",
  "published": "2026-09-11T19:46:27.018Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/036c1b182f4da65363e79ec0ac276edc6b7296e5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2b59029b8f24a99b5d844af2da3950d39d36eeea"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4ed8d2317aef21cc2a9e5a55d6b59860b4b151a8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/60680ae7243b22de3d09be990d8e23bcfc4af837"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/659ee3da073164e1e6e40dfcbc26eeed85845f93"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7377fa964b8aaf47cb04e5efcc4c82d15e8c2ce9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/77de363d9a1c8cd35f20482782c612cda085791a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d9e151fea5ed706c1284adacabd869b0be745db2"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89712.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89712"
    },
    {
      "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: restart ssc_expire_umount walk after dropping nfsd_ssc_lock"
}