From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
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 <luiz.von.dentz@intel.com>
Subject: [PATCH 05/15] Bluetooth: HCI: Use skb_pull_data to parse Inquiry Result event
Date:   Tue, 30 Nov 2021 16:02:05 -0800
Message-Id: <20211201000215.1134831-6-luiz.dentz@gmail.com>
In-Reply-To: <20211201000215.1134831-1-luiz.dentz@gmail.com>
References: <20211201000215.1134831-1-luiz.dentz@gmail.com>
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From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This uses skb_pull_data to check the Inquiry Result events received
have the minimum required length.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 include/net/bluetooth/hci.h |  5 +++++
 net/bluetooth/hci_event.c   | 19 ++++++++++++++-----
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/include/net/bluetooth/hci.h b/include/net/bluetooth/hci.h
index 3f57fd677b67..55466bfb972a 100644
--- a/include/net/bluetooth/hci.h
+++ b/include/net/bluetooth/hci.h
@@ -2028,6 +2028,11 @@ struct inquiry_info {
 	__le16   clock_offset;
 } __packed;
 
+struct hci_ev_inquiry_result {
+	__u8    num;
+	struct inquiry_info info[];
+};
+
 #define HCI_EV_CONN_COMPLETE		0x03
 struct hci_ev_conn_complete {
 	__u8     status;
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index b27a4ad647ca..0bf062f6f262 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -3180,13 +3180,21 @@ static void hci_inquiry_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
 
 static void hci_inquiry_result_evt(struct hci_dev *hdev, struct sk_buff *skb)
 {
+	struct hci_ev_inquiry_result *ev;
 	struct inquiry_data data;
-	struct inquiry_info *info = (void *) (skb->data + 1);
-	int num_rsp = *((__u8 *) skb->data);
+	int i;
 
-	BT_DBG("%s num_rsp %d", hdev->name, num_rsp);
+	ev = hci_ev_skb_pull(hdev, skb, HCI_EV_INQUIRY_RESULT, sizeof(*ev));
+	if (!ev)
+		return;
 
-	if (!num_rsp || skb->len < num_rsp * sizeof(*info) + 1)
+	if (!hci_ev_skb_pull(hdev, skb, HCI_EV_INQUIRY_RESULT,
+			     flex_array_size(ev, info, ev->num)))
+		return;
+
+	BT_DBG("%s num %d", hdev->name, ev->num);
+
+	if (!ev->num)
 		return;
 
 	if (hci_dev_test_flag(hdev, HCI_PERIODIC_INQ))
@@ -3194,7 +3202,8 @@ static void hci_inquiry_result_evt(struct hci_dev *hdev, struct sk_buff *skb)
 
 	hci_dev_lock(hdev);
 
-	for (; num_rsp; num_rsp--, info++) {
+	for (i = 0; i < ev->num; i++) {
+		struct inquiry_info *info = &ev->info[i];
 		u32 flags;
 
 		bacpy(&data.bdaddr, &info->bdaddr);
-- 
2.33.1