Bluetooth: Fix possible NULL pointer derefence in l2cap code

Due to ERTM reliability L2CAP channel needs to be disconnected if
adding to srej list failed.

Signed-off-by: Szymon Janc <szymon.janc@tieto.com>
Signed-off-by: Gustavo F. Padovan <padovan@profusion.mobi>

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 1790ce3..276817a 100644 (file)
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -3788,7 +3788,7 @@ static void l2cap_resend_srejframe(struct l2cap_chan *chan, u16 tx_seq)
        }
 }
 
-static void l2cap_send_srejframe(struct l2cap_chan *chan, u16 tx_seq)
+static int l2cap_send_srejframe(struct l2cap_chan *chan, u16 tx_seq)
 {
        struct srej_list *new;
        u32 control;
@@ -3799,6 +3799,9 @@ static void l2cap_send_srejframe(struct l2cap_chan *chan, u16 tx_seq)
                l2cap_send_sframe(chan, control);
 
                new = kzalloc(sizeof(struct srej_list), GFP_ATOMIC);
+               if (!new)
+                       return -ENOMEM;
+
                new->tx_seq = chan->expected_tx_seq;
 
                chan->expected_tx_seq = __next_seq(chan, chan->expected_tx_seq);
@@ -3807,6 +3810,8 @@ static void l2cap_send_srejframe(struct l2cap_chan *chan, u16 tx_seq)
        }
 
        chan->expected_tx_seq = __next_seq(chan, chan->expected_tx_seq);
+
+       return 0;
 }
 
 static inline int l2cap_data_channel_iframe(struct l2cap_chan *chan, u32 rx_control, struct sk_buff *skb)
@@ -3877,7 +3882,12 @@ static inline int l2cap_data_channel_iframe(struct l2cap_chan *chan, u32 rx_cont
                                        return 0;
                                }
                        }
-                       l2cap_send_srejframe(chan, tx_seq);
+
+                       err = l2cap_send_srejframe(chan, tx_seq);
+                       if (err < 0) {
+                               l2cap_send_disconn_req(chan->conn, chan, -err);
+                               return err;
+                       }
                }
        } else {
                expected_tx_seq_offset = __seq_offset(chan,
@@ -3899,7 +3909,11 @@ static inline int l2cap_data_channel_iframe(struct l2cap_chan *chan, u32 rx_cont
 
                set_bit(CONN_SEND_PBIT, &chan->conn_state);
 
-               l2cap_send_srejframe(chan, tx_seq);
+               err = l2cap_send_srejframe(chan, tx_seq);
+               if (err < 0) {
+                       l2cap_send_disconn_req(chan->conn, chan, -err);
+                       return err;
+               }
 
                __clear_ack_timer(chan);
        }