[PATCH 6.19 182/311] Bluetooth: hci_event: move wake reason storage into validated event handlers

Greg Kroah-Hartman
2026-04-08T18:57:34Z

From: Oleh Konko <security@1seal.org>

commit 2b2bf47cd75518c36fa2d41380e4a40641cc89cd upstream.

hci_store_wake_reason() is called from hci_event_packet() immediately
after stripping the HCI event header but before hci_event_func()
enforces the per-event minimum payload length from hci_ev_table.
This means a short HCI event frame can reach bacpy() before any bounds
check runs.

Rather than duplicating skb parsing and per-event length checks inside
hci_store_wake_reason(), move wake-address storage into the individual
event handlers after their existing event-length validation has
succeeded. Convert hci_store_wake_reason() into a small helper that only
stores an already-validated bdaddr while the caller holds hci_dev_lock().
Use the same helper after hci_event_func() with a NULL address to
preserve the existing unexpected-wake fallback semantics when no
validated event handler records a wake address.

Annotate the helper with __must_hold(&hdev->lock) and add
lockdep_assert_held(&hdev->lock) so future call paths keep the lock
contract explicit.

Call the helper from hci_conn_request_evt(), hci_conn_complete_evt(),
hci_sync_conn_complete_evt(), le_conn_complete_evt(),
hci_le_adv_report_evt(), hci_le_ext_adv_report_evt(),
hci_le_direct_adv_report_evt(), hci_le_pa_sync_established_evt(), and
hci_le_past_received_evt().

Fixes: 2f20216c1d6f ("Bluetooth: Emit controller suspend and resume events")
Cc: stable@vger.kernel.org
Signed-off-by: Oleh Konko <security@1seal.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/bluetooth/hci_event.c | 94 +++++++++++++++++-----------------------------
1 file changed, 35 insertions(+), 59 deletions(-)

--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -80,6 +80,10 @@ static void *hci_le_ev_skb_pull(struct h
return data;
}

+static void hci_store_wake_reason(struct hci_dev *hdev,
+ const bdaddr_t *bdaddr, u8 addr_type)
+ __must_hold(&hdev->lock);
+
static u8 hci_cc_inquiry_cancel(struct hci_dev *hdev, void *data,
struct sk_buff *skb)
{
@@ -3111,6 +3115,7 @@ static void hci_conn_complete_evt(struct
bt_dev_dbg(hdev, "status 0x%2.2x", status);

hci_dev_lock(hdev);
+ hci_store_wake_reason(hdev, &ev->bdaddr, BDADDR_BREDR);

/* Check for existing connection:
*
@@ -3274,6 +3279,10 @@ static void hci_conn_request_evt(struct

bt_dev_dbg(hdev, "bdaddr %pMR type 0x%x", &ev->bdaddr, ev->link_type);

+ hci_dev_lock(hdev);
+ hci_store_wake_reason(hdev, &ev->bdaddr, BDADDR_BREDR);
+ hci_dev_unlock(hdev);
+
/* Reject incoming connection from device with same BD ADDR against
* CVE-2020-26555
*/
@@ -5021,6 +5030,7 @@ static void hci_sync_conn_complete_evt(s
bt_dev_dbg(hdev, "status 0x%2.2x", status);

hci_dev_lock(hdev);
+ hci_store_wake_reason(hdev, &ev->bdaddr, BDADDR_BREDR);

conn = hci_conn_hash_lookup_ba(hdev, ev->link_type, &ev->bdaddr);
if (!conn) {
@@ -5713,6 +5723,7 @@ static void le_conn_complete_evt(struct
int err;

hci_dev_lock(hdev);
+ hci_store_wake_reason(hdev, bdaddr, bdaddr_type);

/* All controllers implicitly stop advertising in the event of a
* connection, so ensure that the state bit is cleared.
@@ -6005,6 +6016,7 @@ static void hci_le_past_received_evt(str
bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);

hci_dev_lock(hdev);
+ hci_store_wake_reason(hdev, &ev->bdaddr, ev->bdaddr_type);

hci_dev_clear_flag(hdev, HCI_PA_SYNC);

@@ -6403,6 +6415,8 @@ static void hci_le_adv_report_evt(struct
info->length + 1))
break;

+ hci_store_wake_reason(hdev, &info->bdaddr, info->bdaddr_type);
+
if (info->length <= max_adv_len(hdev)) {
rssi = info->data[info->length];
process_adv_report(hdev, info->type, &info->bdaddr,
@@ -6491,6 +6505,8 @@ static void hci_le_ext_adv_report_evt(st
info->length))
break;

+ hci_store_wake_reason(hdev, &info->bdaddr, info->bdaddr_type);
+
evt_type = __le16_to_cpu(info->type) & LE_EXT_ADV_EVT_TYPE_MASK;
legacy_evt_type = ext_evt_type_to_legacy(hdev, evt_type);

@@ -6536,6 +6552,7 @@ static void hci_le_pa_sync_established_e
bt_dev_dbg(hdev, "status 0x%2.2x", ev->status);

hci_dev_lock(hdev);
+ hci_store_wake_reason(hdev, &ev->bdaddr, ev->bdaddr_type);

hci_dev_clear_flag(hdev, HCI_PA_SYNC);

@@ -6841,6 +6858,8 @@ static void hci_le_direct_adv_report_evt
for (i = 0; i < ev->num; i++) {
struct hci_ev_le_direct_adv_info *info = &ev->info[i];

+ hci_store_wake_reason(hdev, &info->bdaddr, info->bdaddr_type);
+
process_adv_report(hdev, info->type, &info->bdaddr,
info->bdaddr_type, &info->direct_addr,
info->direct_addr_type, HCI_ADV_PHY_1M, 0,
@@ -7509,73 +7528,29 @@ static bool hci_get_cmd_complete(struct
return true;
}

-static void hci_store_wake_reason(struct hci_dev *hdev, u8 event,
- struct sk_buff *skb)
+static void hci_store_wake_reason(struct hci_dev *hdev,
+ const bdaddr_t *bdaddr, u8 addr_type)
+ __must_hold(&hdev->lock)
{
- struct hci_ev_le_advertising_info *adv;
- struct hci_ev_le_direct_adv_info *direct_adv;
- struct hci_ev_le_ext_adv_info *ext_adv;
- const struct hci_ev_conn_complete *conn_complete = (void *)skb->data;
- const struct hci_ev_conn_request *conn_request = (void *)skb->data;
-
- hci_dev_lock(hdev);
+ lockdep_assert_held(&hdev->lock);

/* If we are currently suspended and this is the first BT event seen,
* save the wake reason associated with the event.
*/
if (!hdev->suspended || hdev->wake_reason)
- goto unlock;
+ return;
+
+ if (!bdaddr) {
+ hdev->wake_reason = MGMT_WAKE_REASON_UNEXPECTED;
+ return;
+ }

/* Default to remote wake. Values for wake_reason are documented in the
* Bluez mgmt api docs.
*/
hdev->wake_reason = MGMT_WAKE_REASON_REMOTE_WAKE;
-
- /* Once configured for remote wakeup, we should only wake up for
- * reconnections. It's useful to see which device is waking us up so
- * keep track of the bdaddr of the connection event that woke us up.
- */
- if (event == HCI_EV_CONN_REQUEST) {
- bacpy(&hdev->wake_addr, &conn_request->bdaddr);
- hdev->wake_addr_type = BDADDR_BREDR;
- } else if (event == HCI_EV_CONN_COMPLETE) {
- bacpy(&hdev->wake_addr, &conn_complete->bdaddr);
- hdev->wake_addr_type = BDADDR_BREDR;
- } else if (event == HCI_EV_LE_META) {
- struct hci_ev_le_meta *le_ev = (void *)skb->data;
- u8 subevent = le_ev->subevent;
- u8 *ptr = &skb->data[sizeof(*le_ev)];
- u8 num_reports = *ptr;
-
- if ((subevent == HCI_EV_LE_ADVERTISING_REPORT ||
- subevent == HCI_EV_LE_DIRECT_ADV_REPORT ||
- subevent == HCI_EV_LE_EXT_ADV_REPORT) &&
- num_reports) {
- adv = (void *)(ptr + 1);
- direct_adv = (void *)(ptr + 1);
- ext_adv = (void *)(ptr + 1);
-
- switch (subevent) {
- case HCI_EV_LE_ADVERTISING_REPORT:
- bacpy(&hdev->wake_addr, &adv->bdaddr);
- hdev->wake_addr_type = adv->bdaddr_type;
- break;
- case HCI_EV_LE_DIRECT_ADV_REPORT:
- bacpy(&hdev->wake_addr, &direct_adv->bdaddr);
- hdev->wake_addr_type = direct_adv->bdaddr_type;
- break;
- case HCI_EV_LE_EXT_ADV_REPORT:
- bacpy(&hdev->wake_addr, &ext_adv->bdaddr);
- hdev->wake_addr_type = ext_adv->bdaddr_type;
- break;
- }
- }
- } else {
- hdev->wake_reason = MGMT_WAKE_REASON_UNEXPECTED;
- }
-
-unlock:
- hci_dev_unlock(hdev);
+ bacpy(&hdev->wake_addr, bdaddr);
+ hdev->wake_addr_type = addr_type;
}

#define HCI_EV_VL(_op, _func, _min_len, _max_len) \
@@ -7822,14 +7797,15 @@ void hci_event_packet(struct hci_dev *hd

skb_pull(skb, HCI_EVENT_HDR_SIZE);

- /* Store wake reason if we're suspended */
- hci_store_wake_reason(hdev, event, skb);
-
bt_dev_dbg(hdev, "event 0x%2.2x", event);

hci_event_func(hdev, event, skb, &opcode, &status, &req_complete,
&req_complete_skb);

+ hci_dev_lock(hdev);
+ hci_store_wake_reason(hdev, NULL, 0);
+ hci_dev_unlock(hdev);
+
if (req_complete) {
req_complete(hdev, status, opcode);
} else if (req_complete_skb) {