diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 6db60946c627..962aa11ce3de 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1239,6 +1239,10 @@ static void l2cap_sock_kill(struct sock *sk) BT_DBG("sk %p state %s", sk, state_to_string(sk->sk_state)); + /* Sock is dead, so set chan data to NULL, avoid other task use invalid + * sock pointer. + */ + l2cap_pi(sk)->chan->data = NULL; /* Kill poor orphan */ l2cap_chan_put(l2cap_pi(sk)->chan); @@ -1481,12 +1485,25 @@ static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan) static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) { - struct sock *sk = chan->data; - struct l2cap_pinfo *pi = l2cap_pi(sk); + struct sock *sk; + struct l2cap_pinfo *pi; int err; - lock_sock(sk); + /* To avoid race with sock_release, a chan lock needs to be added here + * to synchronize the sock. + */ + l2cap_chan_hold(chan); + l2cap_chan_lock(chan); + sk = chan->data; + if (!sk) { + l2cap_chan_unlock(chan); + l2cap_chan_put(chan); + return -ENXIO; + } + + pi = l2cap_pi(sk); + lock_sock(sk); if (chan->mode == L2CAP_MODE_ERTM && !list_empty(&pi->rx_busy)) { err = -ENOMEM; goto done; @@ -1535,6 +1552,8 @@ static int l2cap_sock_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) done: release_sock(sk); + l2cap_chan_unlock(chan); + l2cap_chan_put(chan); return err; }