From e3643fbddb257c928c075cab05bbd929106b56ee Mon Sep 17 00:00:00 2001 From: Laxman Acharya Date: Wed, 5 Aug 2026 23:22:01 +0545 Subject: [PATCH] Bluetooth: hci_event: fix out-of-bounds read in LE PA report reassembly hci_le_per_adv_report_evt() is dispatched with a minimum length of sizeof(struct hci_ev_le_per_adv_report), which only covers the fixed part of the event and not the trailing data[] array: struct hci_ev_le_per_adv_report { __le16 sync_handle; __u8 tx_power; __u8 rssi; __u8 cte_type; __u8 data_status; __u8 length; __u8 data[]; } __packed; The handler notifies the ISO layer via hci_proto_connect_ind(), which reaches iso_connect_ind(). That function retrieves the stored event with hci_recv_event_data() and, while reassembling the periodic advertising data, does: memcpy(hcon->le_per_adv_data + hcon->le_per_adv_data_offset, ev->data, ev->length); ev->length is taken directly from the event and is never validated against the amount of data the event actually carries. A controller that reports a length larger than the received event therefore causes the memcpy() to read past the end of the event buffer. The leaked bytes are stored in hcon->le_per_adv_data and can subsequently be read back from user space via getsockopt(BT_ISO_BASE). Validate that the event contains ev->length data bytes before it is consumed, mirroring the check already performed by hci_le_ext_adv_report_evt() and hci_le_adv_report_evt(). Signed-off-by: Laxman Acharya Signed-off-by: Luiz Augusto von Dentz --- net/bluetooth/hci_event.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 371ca8236bc5..3eb1eaf6e6a0 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -6658,6 +6658,13 @@ static void hci_le_per_adv_report_evt(struct hci_dev *hdev, void *data, bt_dev_dbg(hdev, "sync_handle 0x%4.4x", le16_to_cpu(ev->sync_handle)); + /* The reassembly in iso_connect_ind() copies ev->length bytes from the + * stored event, so make sure the event actually carries that many data + * bytes before it is consumed. + */ + if (!hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_PER_ADV_REPORT, ev->length)) + return; + hci_dev_lock(hdev); mask |= hci_proto_connect_ind(hdev, BDADDR_ANY, PA_LINK, &flags);