Bluetooth: Fix skb allocation in mgmt_remote_name() & mgmt_device_connected()

This patch fixes skb allocation, as lack of space for ev might push skb
tail beyond its end.
Also introduce eir_precalc_len() that can be used instead of magic
numbers for similar eir operations on skb.

Fixes: cf1bce1de7eeb ("Bluetooth: mgmt: Make use of mgmt_send_event_skb in MGMT_EV_DEVICE_FOUND")
Fixes: e96741437ef0a ("Bluetooth: mgmt: Make use of mgmt_send_event_skb in MGMT_EV_DEVICE_CONNECTED")
Signed-off-by: Angela Czubak <acz@semihalf.com>
Signed-off-by: Marek Maslanka <mm@semihalf.com>
Signed-off-by: Radoslaw Biernacki <rad@semihalf.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

diff --git a/net/bluetooth/eir.h b/net/bluetooth/eir.h
index 05e2e91..e587675 100644 (file)
--- a/net/bluetooth/eir.h
+++ b/net/bluetooth/eir.h
@@ -15,6 +15,11 @@ u8 eir_create_scan_rsp(struct hci_dev *hdev, u8 instance, u8 *ptr);
 u8 eir_append_local_name(struct hci_dev *hdev, u8 *eir, u8 ad_len);
 u8 eir_append_appearance(struct hci_dev *hdev, u8 *ptr, u8 ad_len);
 
+static inline u16 eir_precalc_len(u8 data_len)
+{
+       return sizeof(u8) * 2 + data_len;
+}
+
 static inline u16 eir_append_data(u8 *eir, u16 eir_len, u8 type,
                                  u8 *data, u8 data_len)
 {

diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index e0d36d1..bfacf2e 100644 (file)
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -9085,12 +9085,14 @@ void mgmt_device_connected(struct hci_dev *hdev, struct hci_conn *conn,
        u16 eir_len = 0;
        u32 flags = 0;
 
+       /* allocate buff for LE or BR/EDR adv */
        if (conn->le_adv_data_len > 0)
                skb = mgmt_alloc_skb(hdev, MGMT_EV_DEVICE_CONNECTED,
-                                    conn->le_adv_data_len);
+                                    sizeof(*ev) + conn->le_adv_data_len);
        else
                skb = mgmt_alloc_skb(hdev, MGMT_EV_DEVICE_CONNECTED,
-                                    2 + name_len + 5);
+                                    sizeof(*ev) + (name ? eir_precalc_len(name_len) : 0) +
+                                    eir_precalc_len(sizeof(conn->dev_class)));
 
        ev = skb_put(skb, sizeof(*ev));
        bacpy(&ev->addr.bdaddr, &conn->dst);
@@ -9809,13 +9811,11 @@ void mgmt_remote_name(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
 {
        struct sk_buff *skb;
        struct mgmt_ev_device_found *ev;
-       u16 eir_len;
-       u32 flags;
+       u16 eir_len = 0;
+       u32 flags = 0;
 
-       if (name_len)
-               skb = mgmt_alloc_skb(hdev, MGMT_EV_DEVICE_FOUND, 2 + name_len);
-       else
-               skb = mgmt_alloc_skb(hdev, MGMT_EV_DEVICE_FOUND, 0);
+       skb = mgmt_alloc_skb(hdev, MGMT_EV_DEVICE_FOUND,
+                            sizeof(*ev) + (name ? eir_precalc_len(name_len) : 0));
 
        ev = skb_put(skb, sizeof(*ev));
        bacpy(&ev->addr.bdaddr, bdaddr);
@@ -9825,10 +9825,8 @@ void mgmt_remote_name(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 link_type,
        if (name) {
                eir_len = eir_append_data(ev->eir, 0, EIR_NAME_COMPLETE, name,
                                          name_len);
-               flags = 0;
                skb_put(skb, eir_len);
        } else {
-               eir_len = 0;
                flags = MGMT_DEV_FOUND_NAME_REQUEST_FAILED;
        }