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[71.56.157.77]) by smtp.gmail.com with ESMTPSA id j13sm21001739pfc.151.2021.11.30.16.03.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Nov 2021 16:03:06 -0800 (PST) From: Luiz Augusto von Dentz To: davem@davemloft.net, kuba@kernel.org Cc: linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org, dan.carpenter@oracle.com, Luiz Augusto von Dentz Subject: [PATCH 09/15] Bluetooth: HCI: Use skb_pull_data to parse LE Advertising Report event Date: Tue, 30 Nov 2021 16:02:09 -0800 Message-Id: <20211201000215.1134831-10-luiz.dentz@gmail.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211201000215.1134831-1-luiz.dentz@gmail.com> References: <20211201000215.1134831-1-luiz.dentz@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org From: Luiz Augusto von Dentz This uses skb_pull_data to check the LE Advertising Report events received have the minimum required length. Signed-off-by: Luiz Augusto von Dentz --- include/net/bluetooth/hci.h | 7 ++++++- net/bluetooth/hci_event.c | 39 +++++++++++++++++++++++-------------- 2 files changed, 30 insertions(+), 16 deletions(-) diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h index 9e721e6efef3..c005b1ccdbc5 100644 --- a/include/net/bluetooth/hci.h +++ b/include/net/bluetooth/hci.h @@ -2445,13 +2445,18 @@ struct hci_ev_le_conn_complete { #define HCI_EV_LE_ADVERTISING_REPORT 0x02 struct hci_ev_le_advertising_info { - __u8 evt_type; + __u8 type; __u8 bdaddr_type; bdaddr_t bdaddr; __u8 length; __u8 data[]; } __packed; +struct hci_ev_le_advertising_report { + __u8 num; + struct hci_ev_le_advertising_info info[]; +} __packed; + #define HCI_EV_LE_CONN_UPDATE_COMPLETE 0x03 struct hci_ev_le_conn_update_complete { __u8 status; diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index d30e77f66376..42ffd5df6d4b 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -6564,31 +6564,40 @@ static void process_adv_report(struct hci_dev *hdev, u8 type, bdaddr_t *bdaddr, static void hci_le_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb) { - u8 num_reports = skb->data[0]; - void *ptr = &skb->data[1]; + struct hci_ev_le_advertising_report *ev; + + ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_ADVERTISING_REPORT, + sizeof(*ev)); + if (!ev) + return; + + if (!ev->num) + return; hci_dev_lock(hdev); - while (num_reports--) { - struct hci_ev_le_advertising_info *ev = ptr; + while (ev->num--) { + struct hci_ev_le_advertising_info *info; s8 rssi; - if (ptr > (void *)skb_tail_pointer(skb) - sizeof(*ev)) { - bt_dev_err(hdev, "Malicious advertising data."); + info = hci_le_ev_skb_pull(hdev, skb, + HCI_EV_LE_ADVERTISING_REPORT, + sizeof(*info)); + if (!info) break; - } - if (ev->length <= HCI_MAX_AD_LENGTH && - ev->data + ev->length <= skb_tail_pointer(skb)) { - rssi = ev->data[ev->length]; - process_adv_report(hdev, ev->evt_type, &ev->bdaddr, - ev->bdaddr_type, NULL, 0, rssi, - ev->data, ev->length, false); + if (!hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_ADVERTISING_REPORT, + info->length + 1)) + break; + + if (info->length <= HCI_MAX_AD_LENGTH) { + rssi = info->data[info->length]; + process_adv_report(hdev, info->type, &info->bdaddr, + info->bdaddr_type, NULL, 0, rssi, + info->data, info->length, false); } else { bt_dev_err(hdev, "Dropping invalid advertising data"); } - - ptr += sizeof(*ev) + ev->length + 1; } hci_dev_unlock(hdev);