[PATCH 08/15] Bluetooth: HCI: Use skb_pull_data to parse LE Metaevents

Luiz Augusto von Dentz
2021-12-01T00:03:31Z

This uses skb_pull_data to check the LE Metaevents received have the
minimum required length.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
net/bluetooth/hci_event.c | 75 +++++++++++++++++++++++++++++++++------
1 file changed, 64 insertions(+), 11 deletions(-)

diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index 89c263c1883f..d30e77f66376 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -69,6 +69,18 @@ static void *hci_cc_skb_pull(struct hci_dev *hdev, struct sk_buff *skb,
return data;
}

+static void *hci_le_ev_skb_pull(struct hci_dev *hdev, struct sk_buff *skb,
+ u8 ev, size_t len)
+{
+ void *data;
+
+ data = skb_pull_data(skb, len);
+ if (!data)
+ bt_dev_err(hdev, "Malformed LE Event: 0x%2.2x", ev);
+
+ return data;
+}
+
static void hci_cc_inquiry_cancel(struct hci_dev *hdev, struct sk_buff *skb,
u8 *new_status)
{
@@ -6119,7 +6131,12 @@ static void le_conn_complete_evt(struct hci_dev *hdev, u8 status,

static void hci_le_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
{
- struct hci_ev_le_conn_complete *ev = (void *) skb->data;
+ struct hci_ev_le_conn_complete *ev;
+
+ ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_CONN_COMPLETE,
+ sizeof(*ev));
+ if (!ev)
+ return;

BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);

@@ -6133,7 +6150,12 @@ static void hci_le_conn_complete_evt(struct hci_dev *hdev, struct sk_buff *skb)
static void hci_le_enh_conn_complete_evt(struct hci_dev *hdev,
struct sk_buff *skb)
{
- struct hci_ev_le_enh_conn_complete *ev = (void *) skb->data;
+ struct hci_ev_le_enh_conn_complete *ev;
+
+ ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_ENHANCED_CONN_COMPLETE,
+ sizeof(*ev));
+ if (!ev)
+ return;

BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);

@@ -6146,10 +6168,15 @@ static void hci_le_enh_conn_complete_evt(struct hci_dev *hdev,

static void hci_le_ext_adv_term_evt(struct hci_dev *hdev, struct sk_buff *skb)
{
- struct hci_evt_le_ext_adv_set_term *ev = (void *) skb->data;
+ struct hci_evt_le_ext_adv_set_term *ev;
struct hci_conn *conn;
struct adv_info *adv, *n;

+ ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_EXT_ADV_SET_TERM,
+ sizeof(*ev));
+ if (!ev)
+ return;
+
BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);

adv = hci_find_adv_instance(hdev, ev->handle);
@@ -6211,9 +6238,14 @@ static void hci_le_ext_adv_term_evt(struct hci_dev *hdev, struct sk_buff *skb)
static void hci_le_conn_update_complete_evt(struct hci_dev *hdev,
struct sk_buff *skb)
{
- struct hci_ev_le_conn_update_complete *ev = (void *) skb->data;
+ struct hci_ev_le_conn_update_complete *ev;
struct hci_conn *conn;

+ ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_CONN_UPDATE_COMPLETE,
+ sizeof(*ev));
+ if (!ev)
+ return;
+
BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);

if (ev->status)
@@ -6636,9 +6668,14 @@ static void hci_le_ext_adv_report_evt(struct hci_dev *hdev, struct sk_buff *skb)
static void hci_le_remote_feat_complete_evt(struct hci_dev *hdev,
struct sk_buff *skb)
{
- struct hci_ev_le_remote_feat_complete *ev = (void *)skb->data;
+ struct hci_ev_le_remote_feat_complete *ev;
struct hci_conn *conn;

+ ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_EXT_ADV_REPORT,
+ sizeof(*ev));
+ if (!ev)
+ return;
+
BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);

hci_dev_lock(hdev);
@@ -6677,12 +6714,16 @@ static void hci_le_remote_feat_complete_evt(struct hci_dev *hdev,

static void hci_le_ltk_request_evt(struct hci_dev *hdev, struct sk_buff *skb)
{
- struct hci_ev_le_ltk_req *ev = (void *) skb->data;
+ struct hci_ev_le_ltk_req *ev;
struct hci_cp_le_ltk_reply cp;
struct hci_cp_le_ltk_neg_reply neg;
struct hci_conn *conn;
struct smp_ltk *ltk;

+ ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_LTK_REQ, sizeof(*ev));
+ if (!ev)
+ return;
+
BT_DBG("%s handle 0x%4.4x", hdev->name, __le16_to_cpu(ev->handle));

hci_dev_lock(hdev);
@@ -6754,11 +6795,16 @@ static void send_conn_param_neg_reply(struct hci_dev *hdev, u16 handle,
static void hci_le_remote_conn_param_req_evt(struct hci_dev *hdev,
struct sk_buff *skb)
{
- struct hci_ev_le_remote_conn_param_req *ev = (void *) skb->data;
+ struct hci_ev_le_remote_conn_param_req *ev;
struct hci_cp_le_conn_param_req_reply cp;
struct hci_conn *hcon;
u16 handle, min, max, latency, timeout;

+ ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_REMOTE_CONN_PARAM_REQ,
+ sizeof(*ev));
+ if (!ev)
+ return;
+
handle = le16_to_cpu(ev->handle);
min = le16_to_cpu(ev->interval_min);
max = le16_to_cpu(ev->interval_max);
@@ -6831,9 +6877,14 @@ static void hci_le_direct_adv_report_evt(struct hci_dev *hdev,

static void hci_le_phy_update_evt(struct hci_dev *hdev, struct sk_buff *skb)
{
- struct hci_ev_le_phy_update_complete *ev = (void *) skb->data;
+ struct hci_ev_le_phy_update_complete *ev;
struct hci_conn *conn;

+ ev = hci_le_ev_skb_pull(hdev, skb, HCI_EV_LE_PHY_UPDATE_COMPLETE,
+ sizeof(*ev));
+ if (ev)
+ return;
+
BT_DBG("%s status 0x%2.2x", hdev->name, ev->status);

if (ev->status)
@@ -6854,11 +6905,13 @@ static void hci_le_phy_update_evt(struct hci_dev *hdev, struct sk_buff *skb)

static void hci_le_meta_evt(struct hci_dev *hdev, struct sk_buff *skb)
{
- struct hci_ev_le_meta *le_ev = (void *) skb->data;
+ struct hci_ev_le_meta *ev;

- skb_pull(skb, sizeof(*le_ev));
+ ev = hci_ev_skb_pull(hdev, skb, HCI_EV_LE_META, sizeof(*ev));
+ if (!ev)
+ return;

- switch (le_ev->subevent) {
+ switch (ev->subevent) {
case HCI_EV_LE_CONN_COMPLETE:
hci_le_conn_complete_evt(hdev, skb);
break;
--
2.33.1