{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "2f20216c1d6fe17c1a224f658be0dc6fab2269c7"
            },
            {
              "fixed": "86c8d07a64d553c41e213b52650020010f9ef23e"
            },
            {
              "fixed": "2b2bf47cd75518c36fa2d41380e4a40641cc89cd"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.10.0"
            },
            {
              "fixed": "6.19.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31771.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_event: move wake reason storage into validated event handlers\n\nhci_store_wake_reason() is called from hci_event_packet() immediately\nafter stripping the HCI event header but before hci_event_func()\nenforces the per-event minimum payload length from hci_ev_table.\nThis means a short HCI event frame can reach bacpy() before any bounds\ncheck runs.\n\nRather than duplicating skb parsing and per-event length checks inside\nhci_store_wake_reason(), move wake-address storage into the individual\nevent handlers after their existing event-length validation has\nsucceeded. Convert hci_store_wake_reason() into a small helper that only\nstores an already-validated bdaddr while the caller holds hci_dev_lock().\nUse the same helper after hci_event_func() with a NULL address to\npreserve the existing unexpected-wake fallback semantics when no\nvalidated event handler records a wake address.\n\nAnnotate the helper with __must_hold(\u0026hdev-\u003elock) and add\nlockdep_assert_held(\u0026hdev-\u003elock) so future call paths keep the lock\ncontract explicit.\n\nCall the helper from hci_conn_request_evt(), hci_conn_complete_evt(),\nhci_sync_conn_complete_evt(), le_conn_complete_evt(),\nhci_le_adv_report_evt(), hci_le_ext_adv_report_evt(),\nhci_le_direct_adv_report_evt(), hci_le_pa_sync_established_evt(), and\nhci_le_past_received_evt().",
  "id": "CVE-2026-31771",
  "modified": "2026-07-08T05:36:50.925109763Z",
  "published": "2026-05-01T14:14:59.918Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2b2bf47cd75518c36fa2d41380e4a40641cc89cd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/86c8d07a64d553c41e213b52650020010f9ef23e"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31771.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31771"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Bluetooth: hci_event: move wake reason storage into validated event handlers"
}