Bluetooth: Change sk lock to chan lock in L2CAP core

Change sk lock to chan lock in l2cap core and move sk locks
to l2cap sock code. bh_locks were used because of being RCU
critical section. When needed use explicit socket locks.

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Reviewed-by: Ulisses Furquim <ulisses@profusion.mobi>
Acked-by: Gustavo F. Padovan <padovan@profusion.mobi>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>

2 files changed, 114 insertions, 70 deletions

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 0e4f4cb..5f4cfea 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -238,13 +238,12 @@ static void l2cap_chan_timeout(struct work_struct *work)
 	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
 							chan_timer.work);
 	struct l2cap_conn *conn = chan->conn;
-	struct sock *sk = chan->sk;
 	int reason;
 
 	BT_DBG("chan %p state %s", chan, state_to_string(chan->state));
 
 	mutex_lock(&conn->chan_lock);
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	if (chan->state == BT_CONNECTED || chan->state == BT_CONFIG)
 		reason = ECONNREFUSED;
@@ -256,7 +255,7 @@ static void l2cap_chan_timeout(struct work_struct *work)
 
 	l2cap_chan_close(chan, reason);
 
-	release_sock(sk);
+	l2cap_chan_unlock(chan);
 
 	chan->ops->close(chan->data);
 	mutex_unlock(&conn->chan_lock);
@@ -356,8 +355,6 @@ void l2cap_chan_add(struct l2cap_conn *conn, struct l2cap_chan *chan)
 	mutex_unlock(&conn->chan_lock);
 }
 
-/* Delete channel.
- * Must be called on the locked socket. */
 static void l2cap_chan_del(struct l2cap_chan *chan, int err)
 {
 	struct sock *sk = chan->sk;
@@ -378,6 +375,8 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
 		hci_conn_put(conn->hcon);
 	}
 
+	lock_sock(sk);
+
 	__l2cap_state_change(chan, BT_CLOSED);
 	sock_set_flag(sk, SOCK_ZAPPED);
 
@@ -390,6 +389,8 @@ static void l2cap_chan_del(struct l2cap_chan *chan, int err)
 	} else
 		sk->sk_state_change(sk);
 
+	release_sock(sk);
+
 	if (!(test_bit(CONF_OUTPUT_DONE, &chan->conf_state) &&
 			test_bit(CONF_INPUT_DONE, &chan->conf_state)))
 		return;
@@ -422,10 +423,10 @@ static void l2cap_chan_cleanup_listen(struct sock *parent)
 	while ((sk = bt_accept_dequeue(parent, NULL))) {
 		struct l2cap_chan *chan = l2cap_pi(sk)->chan;
 
+		l2cap_chan_lock(chan);
 		__clear_chan_timer(chan);
-		lock_sock(sk);
 		l2cap_chan_close(chan, ECONNRESET);
-		release_sock(sk);
+		l2cap_chan_unlock(chan);
 
 		chan->ops->close(chan->data);
 	}
@@ -441,10 +442,12 @@ void l2cap_chan_close(struct l2cap_chan *chan, int reason)
 
 	switch (chan->state) {
 	case BT_LISTEN:
+		lock_sock(sk);
 		l2cap_chan_cleanup_listen(sk);
 
 		__l2cap_state_change(chan, BT_CLOSED);
 		sock_set_flag(sk, SOCK_ZAPPED);
+		release_sock(sk);
 		break;
 
 	case BT_CONNECTED:
@@ -487,7 +490,9 @@ void l2cap_chan_close(struct l2cap_chan *chan, int reason)
 		break;
 
 	default:
+		lock_sock(sk);
 		sock_set_flag(sk, SOCK_ZAPPED);
+		release_sock(sk);
 		break;
 	}
 }
@@ -715,6 +720,7 @@ static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
 
 static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct l2cap_chan *chan, int err)
 {
+	struct sock *sk = chan->sk;
 	struct l2cap_disconn_req req;
 
 	if (!conn)
@@ -731,8 +737,10 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct l2cap_chan *c
 	l2cap_send_cmd(conn, l2cap_get_ident(conn),
 			L2CAP_DISCONN_REQ, sizeof(req), &req);
 
+	lock_sock(sk);
 	__l2cap_state_change(chan, BT_DISCONN);
 	__l2cap_chan_set_err(chan, err);
+	release_sock(sk);
 }
 
 /* ---- L2CAP connections ---- */
@@ -747,10 +755,10 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 	list_for_each_entry_safe(chan, tmp, &conn->chan_l, list) {
 		struct sock *sk = chan->sk;
 
-		bh_lock_sock(sk);
+		l2cap_chan_lock(chan);
 
 		if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
-			bh_unlock_sock(sk);
+			l2cap_chan_unlock(chan);
 			continue;
 		}
 
@@ -759,17 +767,15 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 
 			if (!l2cap_chan_check_security(chan) ||
 					!__l2cap_no_conn_pending(chan)) {
-				bh_unlock_sock(sk);
+				l2cap_chan_unlock(chan);
 				continue;
 			}
 
 			if (!l2cap_mode_supported(chan->mode, conn->feat_mask)
 					&& test_bit(CONF_STATE2_DEVICE,
 					&chan->conf_state)) {
-				/* l2cap_chan_close() calls list_del(chan)
-				 * so release the lock */
 				l2cap_chan_close(chan, ECONNRESET);
-				bh_unlock_sock(sk);
+				l2cap_chan_unlock(chan);
 				continue;
 			}
 
@@ -789,6 +795,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 			rsp.dcid = cpu_to_le16(chan->scid);
 
 			if (l2cap_chan_check_security(chan)) {
+				lock_sock(sk);
 				if (bt_sk(sk)->defer_setup) {
 					struct sock *parent = bt_sk(sk)->parent;
 					rsp.result = cpu_to_le16(L2CAP_CR_PEND);
@@ -801,6 +808,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 					rsp.result = cpu_to_le16(L2CAP_CR_SUCCESS);
 					rsp.status = cpu_to_le16(L2CAP_CS_NO_INFO);
 				}
+				release_sock(sk);
 			} else {
 				rsp.result = cpu_to_le16(L2CAP_CR_PEND);
 				rsp.status = cpu_to_le16(L2CAP_CS_AUTHEN_PEND);
@@ -811,7 +819,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 
 			if (test_bit(CONF_REQ_SENT, &chan->conf_state) ||
 					rsp.result != L2CAP_CR_SUCCESS) {
-				bh_unlock_sock(sk);
+				l2cap_chan_unlock(chan);
 				continue;
 			}
 
@@ -821,7 +829,7 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 			chan->num_conf_req++;
 		}
 
-		bh_unlock_sock(sk);
+		l2cap_chan_unlock(chan);
 	}
 
 	mutex_unlock(&conn->chan_lock);
@@ -910,7 +918,11 @@ clean:
 static void l2cap_chan_ready(struct l2cap_chan *chan)
 {
 	struct sock *sk = chan->sk;
-	struct sock *parent = bt_sk(sk)->parent;
+	struct sock *parent;
+
+	lock_sock(sk);
+
+	parent = bt_sk(sk)->parent;
 
 	BT_DBG("sk %p, parent %p", sk, parent);
 
@@ -922,6 +934,8 @@ static void l2cap_chan_ready(struct l2cap_chan *chan)
 
 	if (parent)
 		parent->sk_data_ready(parent, 0);
+
+	release_sock(sk);
 }
 
 static void l2cap_conn_ready(struct l2cap_conn *conn)
@@ -939,23 +953,25 @@ static void l2cap_conn_ready(struct l2cap_conn *conn)
 	mutex_lock(&conn->chan_lock);
 
 	list_for_each_entry(chan, &conn->chan_l, list) {
-		struct sock *sk = chan->sk;
 
-		bh_lock_sock(sk);
+		l2cap_chan_lock(chan);
 
 		if (conn->hcon->type == LE_LINK) {
 			if (smp_conn_security(conn, chan->sec_level))
 				l2cap_chan_ready(chan);
 
 		} else if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
+			struct sock *sk = chan->sk;
 			__clear_chan_timer(chan);
+			lock_sock(sk);
 			__l2cap_state_change(chan, BT_CONNECTED);
 			sk->sk_state_change(sk);
+			release_sock(sk);
 
 		} else if (chan->state == BT_CONNECT)
 			l2cap_do_start(chan);
 
-		bh_unlock_sock(sk);
+		l2cap_chan_unlock(chan);
 	}
 
 	mutex_unlock(&conn->chan_lock);
@@ -993,7 +1009,6 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
 {
 	struct l2cap_conn *conn = hcon->l2cap_data;
 	struct l2cap_chan *chan, *l;
-	struct sock *sk;
 
 	if (!conn)
 		return;
@@ -1006,10 +1021,12 @@ static void l2cap_conn_del(struct hci_conn *hcon, int err)
 
 	/* Kill channels */
 	list_for_each_entry_safe(chan, l, &conn->chan_l, list) {
-		sk = chan->sk;
-		lock_sock(sk);
+		l2cap_chan_lock(chan);
+
 		l2cap_chan_del(chan, err);
-		release_sock(sk);
+
+		l2cap_chan_unlock(chan);
+
 		chan->ops->close(chan->data);
 	}
 
@@ -1140,7 +1157,7 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *d
 
 	hci_dev_lock(hdev);
 
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	/* PSM must be odd and lsb of upper byte must be 0 */
 	if ((__le16_to_cpu(psm) & 0x0101) != 0x0001 && !cid &&
@@ -1167,17 +1184,21 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *d
 		goto done;
 	}
 
+	lock_sock(sk);
+
 	switch (sk->sk_state) {
 	case BT_CONNECT:
 	case BT_CONNECT2:
 	case BT_CONFIG:
 		/* Already connecting */
 		err = 0;
+		release_sock(sk);
 		goto done;
 
 	case BT_CONNECTED:
 		/* Already connected */
 		err = -EISCONN;
+		release_sock(sk);
 		goto done;
 
 	case BT_OPEN:
@@ -1187,11 +1208,15 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *d
 
 	default:
 		err = -EBADFD;
+		release_sock(sk);
 		goto done;
 	}
 
 	/* Set destination address and psm */
 	bacpy(&bt_sk(sk)->dst, dst);
+
+	release_sock(sk);
+
 	chan->psm = psm;
 	chan->dcid = cid;
 
@@ -1219,16 +1244,18 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *d
 	/* Update source addr of the socket */
 	bacpy(src, conn->src);
 
+	l2cap_chan_unlock(chan);
 	l2cap_chan_add(conn, chan);
+	l2cap_chan_lock(chan);
 
-	__l2cap_state_change(chan, BT_CONNECT);
+	l2cap_state_change(chan, BT_CONNECT);
 	__set_chan_timer(chan, sk->sk_sndtimeo);
 
 	if (hcon->state == BT_CONNECTED) {
 		if (chan->chan_type != L2CAP_CHAN_CONN_ORIENTED) {
 			__clear_chan_timer(chan);
 			if (l2cap_chan_check_security(chan))
-				__l2cap_state_change(chan, BT_CONNECTED);
+				l2cap_state_change(chan, BT_CONNECTED);
 		} else
 			l2cap_do_start(chan);
 	}
@@ -1236,6 +1263,7 @@ int l2cap_chan_connect(struct l2cap_chan *chan, __le16 psm, u16 cid, bdaddr_t *d
 	err = 0;
 
 done:
+	l2cap_chan_unlock(chan);
 	hci_dev_unlock(hdev);
 	hci_dev_put(hdev);
 	return err;
@@ -1277,14 +1305,14 @@ static void l2cap_monitor_timeout(struct work_struct *work)
 {
 	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
 							monitor_timer.work);
-	struct sock *sk = chan->sk;
 
 	BT_DBG("chan %p", chan);
 
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
+
 	if (chan->retry_count >= chan->remote_max_tx) {
 		l2cap_send_disconn_req(chan->conn, chan, ECONNABORTED);
-		release_sock(sk);
+		l2cap_chan_unlock(chan);
 		return;
 	}
 
@@ -1292,25 +1320,26 @@ static void l2cap_monitor_timeout(struct work_struct *work)
 	__set_monitor_timer(chan);
 
 	l2cap_send_rr_or_rnr(chan, L2CAP_CTRL_POLL);
-	release_sock(sk);
+	l2cap_chan_unlock(chan);
 }
 
 static void l2cap_retrans_timeout(struct work_struct *work)
 {
 	struct l2cap_chan *chan = container_of(work, struct l2cap_chan,
 							retrans_timer.work);
-	struct sock *sk = chan->sk;
 
 	BT_DBG("chan %p", chan);
 
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
+
 	chan->retry_count = 1;
 	__set_monitor_timer(chan);
 
 	set_bit(CONN_WAIT_F, &chan->conn_state);
 
 	l2cap_send_rr_or_rnr(chan, L2CAP_CTRL_POLL);
-	release_sock(sk);
+
+	l2cap_chan_unlock(chan);
 }
 
 static void l2cap_drop_acked_frames(struct l2cap_chan *chan)
@@ -2001,9 +2030,11 @@ static void l2cap_ack_timeout(struct work_struct *work)
 
 	BT_DBG("chan %p", chan);
 
-	lock_sock(chan->sk);
+	l2cap_chan_lock(chan);
+
 	__l2cap_send_ack(chan);
-	release_sock(chan->sk);
+
+	l2cap_chan_unlock(chan);
 
 	l2cap_chan_put(chan);
 }
@@ -2664,7 +2695,7 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
 
 	bt_accept_enqueue(parent, sk);
 
-	l2cap_chan_add(conn, chan);
+	__l2cap_chan_add(conn, chan);
 
 	dcid = chan->scid;
 
@@ -2737,7 +2768,6 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 	struct l2cap_conn_rsp *rsp = (struct l2cap_conn_rsp *) data;
 	u16 scid, dcid, result, status;
 	struct l2cap_chan *chan;
-	struct sock *sk;
 	u8 req[128];
 	int err;
 
@@ -2767,8 +2797,7 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 
 	err = 0;
 
-	sk = chan->sk;
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	switch (result) {
 	case L2CAP_CR_SUCCESS:
@@ -2794,7 +2823,7 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
 		break;
 	}
 
-	release_sock(sk);
+	l2cap_chan_unlock(chan);
 
 unlock:
 	mutex_unlock(&conn->chan_lock);
@@ -2819,7 +2848,6 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	u16 dcid, flags;
 	u8 rsp[64];
 	struct l2cap_chan *chan;
-	struct sock *sk;
 	int len;
 
 	dcid  = __le16_to_cpu(req->dcid);
@@ -2831,8 +2859,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	if (!chan)
 		return -ENOENT;
 
-	sk = chan->sk;
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	if (chan->state != BT_CONFIG && chan->state != BT_CONNECT2) {
 		struct l2cap_cmd_rej_cid rej;
@@ -2921,7 +2948,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	}
 
 unlock:
-	release_sock(sk);
+	l2cap_chan_unlock(chan);
 	return 0;
 }
 
@@ -2930,7 +2957,6 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	struct l2cap_conf_rsp *rsp = (struct l2cap_conf_rsp *)data;
 	u16 scid, flags, result;
 	struct l2cap_chan *chan;
-	struct sock *sk;
 	int len = cmd->len - sizeof(*rsp);
 
 	scid   = __le16_to_cpu(rsp->scid);
@@ -2944,8 +2970,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	if (!chan)
 		return 0;
 
-	sk = chan->sk;
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	switch (result) {
 	case L2CAP_CONF_SUCCESS:
@@ -3004,7 +3029,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 		}
 
 	default:
-		__l2cap_chan_set_err(chan, ECONNRESET);
+		l2cap_chan_set_err(chan, ECONNRESET);
 
 		__set_chan_timer(chan,
 				msecs_to_jiffies(L2CAP_DISC_REJ_TIMEOUT));
@@ -3031,7 +3056,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 	}
 
 done:
-	release_sock(sk);
+	l2cap_chan_unlock(chan);
 	return 0;
 }
 
@@ -3056,17 +3081,21 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd
 		return 0;
 	}
 
+	l2cap_chan_lock(chan);
+
 	sk = chan->sk;
-	lock_sock(sk);
 
 	rsp.dcid = cpu_to_le16(chan->scid);
 	rsp.scid = cpu_to_le16(chan->dcid);
 	l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
 
+	lock_sock(sk);
 	sk->sk_shutdown = SHUTDOWN_MASK;
+	release_sock(sk);
 
 	l2cap_chan_del(chan, ECONNRESET);
-	release_sock(sk);
+
+	l2cap_chan_unlock(chan);
 
 	chan->ops->close(chan->data);
 
@@ -3080,7 +3109,6 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
 	struct l2cap_disconn_rsp *rsp = (struct l2cap_disconn_rsp *) data;
 	u16 dcid, scid;
 	struct l2cap_chan *chan;
-	struct sock *sk;
 
 	scid = __le16_to_cpu(rsp->scid);
 	dcid = __le16_to_cpu(rsp->dcid);
@@ -3095,11 +3123,11 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
 		return 0;
 	}
 
-	sk = chan->sk;
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	l2cap_chan_del(chan, 0);
-	release_sock(sk);
+
+	l2cap_chan_unlock(chan);
 
 	chan->ops->close(chan->data);
 
@@ -4251,7 +4279,6 @@ drop:
 static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk_buff *skb)
 {
 	struct l2cap_chan *chan;
-	struct sock *sk = NULL;
 	u32 control;
 	u16 tx_seq;
 	int len;
@@ -4259,11 +4286,12 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
 	chan = l2cap_get_chan_by_scid(conn, cid);
 	if (!chan) {
 		BT_DBG("unknown cid 0x%4.4x", cid);
-		goto drop;
+		/* Drop packet and return */
+		kfree(skb);
+		return 0;
 	}
 
-	sk = chan->sk;
-	lock_sock(sk);
+	l2cap_chan_lock(chan);
 
 	BT_DBG("chan %p, len %d", chan, skb->len);
 
@@ -4334,8 +4362,7 @@ drop:
 	kfree_skb(skb);
 
 done:
-	if (sk)
-		release_sock(sk);
+	l2cap_chan_unlock(chan);
 
 	return 0;
 }
@@ -4554,9 +4581,7 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 	mutex_lock(&conn->chan_lock);
 
 	list_for_each_entry(chan, &conn->chan_l, list) {
-		struct sock *sk = chan->sk;
-
-		bh_lock_sock(sk);
+		l2cap_chan_lock(chan);
 
 		BT_DBG("chan->scid %d", chan->scid);
 
@@ -4566,19 +4591,19 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 				l2cap_chan_ready(chan);
 			}
 
-			bh_unlock_sock(sk);
+			l2cap_chan_unlock(chan);
 			continue;
 		}
 
 		if (test_bit(CONF_CONNECT_PEND, &chan->conf_state)) {
-			bh_unlock_sock(sk);
+			l2cap_chan_unlock(chan);
 			continue;
 		}
 
 		if (!status && (chan->state == BT_CONNECTED ||
 						chan->state == BT_CONFIG)) {
 			l2cap_check_encryption(chan, encrypt);
-			bh_unlock_sock(sk);
+			l2cap_chan_unlock(chan);
 			continue;
 		}
 
@@ -4599,9 +4624,12 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 					msecs_to_jiffies(L2CAP_DISC_TIMEOUT));
 			}
 		} else if (chan->state == BT_CONNECT2) {
+			struct sock *sk = chan->sk;
 			struct l2cap_conn_rsp rsp;
 			__u16 res, stat;
 
+			lock_sock(sk);
+
 			if (!status) {
 				if (bt_sk(sk)->defer_setup) {
 					struct sock *parent = bt_sk(sk)->parent;
@@ -4622,6 +4650,8 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 				stat = L2CAP_CS_NO_INFO;
 			}
 
+			release_sock(sk);
+
 			rsp.scid   = cpu_to_le16(chan->dcid);
 			rsp.dcid   = cpu_to_le16(chan->scid);
 			rsp.result = cpu_to_le16(res);
@@ -4630,7 +4660,7 @@ int l2cap_security_cfm(struct hci_conn *hcon, u8 status, u8 encrypt)
 							sizeof(rsp), &rsp);
 		}
 
-		bh_unlock_sock(sk);
+		l2cap_chan_unlock(chan);
 	}
 
 	mutex_unlock(&conn->chan_lock);
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 1273fcb..73a06c1 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -127,6 +127,8 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, int al
 	if (err)
 		goto done;
 
+	lock_sock(sk);
+
 	err = bt_sock_wait_state(sk, BT_CONNECTED,
 			sock_sndtimeo(sk, flags & O_NONBLOCK));
 done:
@@ -810,14 +812,18 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
 	if (conn)
 		mutex_lock(&conn->chan_lock);
 
+	l2cap_chan_lock(chan);
 	lock_sock(sk);
+
 	if (!sk->sk_shutdown) {
 		if (chan->mode == L2CAP_MODE_ERTM)
 			err = __l2cap_wait_ack(sk);
 
 		sk->sk_shutdown = SHUTDOWN_MASK;
 
+		release_sock(sk);
 		l2cap_chan_close(chan, 0);
+		lock_sock(sk);
 
 		if (sock_flag(sk, SOCK_LINGER) && sk->sk_lingertime)
 			err = bt_sock_wait_state(sk, BT_CLOSED,
@@ -828,6 +834,7 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
 		err = -sk->sk_err;
 
 	release_sock(sk);
+	l2cap_chan_unlock(chan);
 
 	if (conn)
 		mutex_unlock(&conn->chan_lock);
@@ -874,8 +881,12 @@ static int l2cap_sock_recv_cb(void *data, struct sk_buff *skb)
 	struct sock *sk = data;
 	struct l2cap_pinfo *pi = l2cap_pi(sk);
 
-	if (pi->rx_busy_skb)
-		return -ENOMEM;
+	lock_sock(sk);
+
+	if (pi->rx_busy_skb) {
+		err = -ENOMEM;
+		goto done;
+	}
 
 	err = sock_queue_rcv_skb(sk, skb);
 
@@ -894,6 +905,9 @@ static int l2cap_sock_recv_cb(void *data, struct sk_buff *skb)
 		err = 0;
 	}
 
+done:
+	release_sock(sk);
+
 	return err;
 }