smb: During unmount, ensure all cached dir instances drop their dentry

{
  "id": "bbb78ff7f0d9e8028ad3249b73e5a0ec3f7b34a61bf40daf4c0a00073a105e96",
  "url": "https://osv.dev/vulnerability/CVE-2024-53176",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "smb: During unmount, ensure all cached dir instances drop their dentry",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: smb: During unmount, ensure all cached dir instances drop their dentry The unmount process (cifs_kill_sb() calling close_all_cached_dirs()) can race with various cached directory operations, which ultimately results in dentries not being dropped and these kernel BUGs: BUG: Dentry ffff88814f37e358{i=1000000000080,n=/} still in use (2) [unmount of cifs cifs] VFS: Busy inodes after unmount of cifs (cifs) ------------[ cut here ]------------ kernel BUG at fs/super.c:661! This happens when a cfid is in the process of being cleaned up when, and has been removed from the cfids->entries list, including: - Receiving a lease break from the server - Server reconnection triggers invalidate_all_cached_dirs(), which removes all the cfids from the list - The laundromat thread decides to expire an old cfid. To solve these problems, dropping the dentry is done in queued work done in a newly-added cfid_put_wq workqueue, and close_all_cached_dirs() flushes that workqueue after it drops all the dentries of which it's aware. This is a global workqueue (rather than scoped to a mount), but the queued work is minimal. The final cleanup work for cleaning up a cfid is performed via work queued in the serverclose_wq workqueue; this is done separate from dropping the dentries so that close_all_cached_dirs() doesn't block on any server operations. Both of these queued works expect to invoked with a cfid reference and a tcon reference to ",
    "evidence": "osv:CVE-2024-53176",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.6.64",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.11.11",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.2",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "CVE-2024-53176",
      "aliases": [
        "CVE-2024-53176"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "ebe98f1447bbccf8228335c62d86af02a0ed23f7"
                },
                {
                  "fixed": "73934e535cffbda1490fa97d82690a0f9aa73e94"
                },
                {
                  "fixed": "ff4528bbc82d0d90073751f7b49e7b9e9c7e5638"
                },
                {
                  "fixed": "548812afd96982a76a93ba76c0582ea670c40d9e"
                },
                {
                  "fixed": "3fa640d035e5ae526769615c35cb9ed4be6e3662"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-53176.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.1.0"
                },
                {
                  "fixed": "6.6.64"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.7.0"
                },
                {
                  "fixed": "6.11.11"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.12.0"
                },
                {
                  "fixed": "6.12.2"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-53176.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:48.053825902Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/3fa640d035e5ae526769615c35cb9ed4be6e3662",
        "https://git.kernel.org/stable/c/548812afd96982a76a93ba76c0582ea670c40d9e",
        "https://git.kernel.org/stable/c/73934e535cffbda1490fa97d82690a0f9aa73e94",
        "https://git.kernel.org/stable/c/ff4528bbc82d0d90073751f7b49e7b9e9c7e5638",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/53xxx/CVE-2024-53176.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2024-53176",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/53xxx/CVE-2024-53176.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2024-53176",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 515886,
  "published_at": "2024-12-27T13:49:20.518+00:00"
}