{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9"
            },
            {
              "fixed": "367c42a611fe488b7b03f1f6737f4dee0e8b20a2"
            },
            {
              "fixed": "7703fd9aba1f2483c8e55f9ff73b7663e0761ed9"
            },
            {
              "fixed": "463bbd79698513af4dad50fe1c573825f297ca2e"
            },
            {
              "fixed": "5aa1cb01155f96824003baf7997cdf1f150caba3"
            },
            {
              "fixed": "5c75275c0fc9a2deb0d8f5604edcb16f288171c8"
            },
            {
              "fixed": "d20d1c8ba5765d1d12eefc0aee6385ab3f240e1e"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.15.0"
            },
            {
              "fixed": "6.1.178"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.96"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.39"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64396.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation\n\nWhen a blocking byte-range lock request is deferred in the\nFILE_LOCK_DEFERRED path, ksmbd registers the asynchronous work into\nthe connection's async_requests list via setup_async_work(). The cancel\ncallback smb2_remove_blocked_lock() holds a reference to the flock.\n\nIf the lock waiter is subsequently woken up but the work state is no\nlonger KSMBD_WORK_ACTIVE (e.g., due to a concurrent cancellation), the\ncleanup path calls locks_free_lock(flock) without dequeuing the work from\nthe async_requests list. Concurrently, smb2_cancel() walks the list\nunder conn-\u003erequest_lock and invokes the cancel callback, which then\ndereferences the already freed 'flock'. This leads to a slab-use-after-free\ninside __wake_up_common.\n\nFix this by restructuring the cleanup logic after the worker returns\nfrom ksmbd_vfs_posix_lock_wait(). Move list_del(\u0026smb_lock-\u003ellist) and\nrelease_async_work(work) to the top of the cleanup block. This guarantees\nthat the async work is completely dequeued and serialized under\nconn-\u003erequest_lock before locks_free_lock(flock) is called, rendering\nthe flock unreachable for any concurrent smb2_cancel().",
  "id": "CVE-2026-64396",
  "modified": "2026-07-28T03:56:06.244648863Z",
  "published": "2026-07-25T08:50:40.993Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/367c42a611fe488b7b03f1f6737f4dee0e8b20a2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/463bbd79698513af4dad50fe1c573825f297ca2e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5aa1cb01155f96824003baf7997cdf1f150caba3"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5c75275c0fc9a2deb0d8f5604edcb16f288171c8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7703fd9aba1f2483c8e55f9ff73b7663e0761ed9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d20d1c8ba5765d1d12eefc0aee6385ab3f240e1e"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64396.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64396"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ksmbd: fix UAF of struct file_lock in SMB2_LOCK deferred-lock cancellation"
}