Bluetooth: Prevent buffer overflow in l2cap config request, CVE-2011-2497
[linux-flexiantxendom0-natty.git] / net / bluetooth / l2cap.c
index c2fb26d..04120ff 100644 (file)
@@ -1,6 +1,8 @@
 /*
    BlueZ - Bluetooth protocol stack for Linux
    Copyright (C) 2000-2001 Qualcomm Incorporated
+   Copyright (C) 2009-2010 Gustavo F. Padovan <gustavo@padovan.org>
+   Copyright (C) 2010 Google Inc.
 
    Written 2000,2001 by Maxim Krasnyansky <maxk@qualcomm.com>
 
@@ -53,9 +55,9 @@
 #include <net/bluetooth/hci_core.h>
 #include <net/bluetooth/l2cap.h>
 
-#define VERSION "2.14"
+#define VERSION "2.15"
 
-static int enable_ertm = 0;
+static int disable_ertm;
 
 static u32 l2cap_feat_mask = L2CAP_FEAT_FIXED_CHAN;
 static u8 l2cap_fixed_chan[8] = { 0x02, };
@@ -74,10 +76,25 @@ static void __l2cap_sock_close(struct sock *sk, int reason);
 static void l2cap_sock_close(struct sock *sk);
 static void l2cap_sock_kill(struct sock *sk);
 
+static int l2cap_build_conf_req(struct sock *sk, void *data);
 static struct sk_buff *l2cap_build_cmd(struct l2cap_conn *conn,
                                u8 code, u8 ident, u16 dlen, void *data);
 
+static int l2cap_ertm_data_rcv(struct sock *sk, struct sk_buff *skb);
+
 /* ---- L2CAP timers ---- */
+static void l2cap_sock_set_timer(struct sock *sk, long timeout)
+{
+       BT_DBG("sk %p state %d timeout %ld", sk, sk->sk_state, timeout);
+       sk_reset_timer(sk, &sk->sk_timer, jiffies + timeout);
+}
+
+static void l2cap_sock_clear_timer(struct sock *sk)
+{
+       BT_DBG("sock %p state %d", sk, sk->sk_state);
+       sk_stop_timer(sk, &sk->sk_timer);
+}
+
 static void l2cap_sock_timeout(unsigned long arg)
 {
        struct sock *sk = (struct sock *) arg;
@@ -87,6 +104,14 @@ static void l2cap_sock_timeout(unsigned long arg)
 
        bh_lock_sock(sk);
 
+       if (sock_owned_by_user(sk)) {
+               /* sk is owned by user. Try again later */
+               l2cap_sock_set_timer(sk, HZ / 5);
+               bh_unlock_sock(sk);
+               sock_put(sk);
+               return;
+       }
+
        if (sk->sk_state == BT_CONNECTED || sk->sk_state == BT_CONFIG)
                reason = ECONNREFUSED;
        else if (sk->sk_state == BT_CONNECT &&
@@ -103,18 +128,6 @@ static void l2cap_sock_timeout(unsigned long arg)
        sock_put(sk);
 }
 
-static void l2cap_sock_set_timer(struct sock *sk, long timeout)
-{
-       BT_DBG("sk %p state %d timeout %ld", sk, sk->sk_state, timeout);
-       sk_reset_timer(sk, &sk->sk_timer, jiffies + timeout);
-}
-
-static void l2cap_sock_clear_timer(struct sock *sk)
-{
-       BT_DBG("sock %p state %d", sk, sk->sk_state);
-       sk_stop_timer(sk, &sk->sk_timer);
-}
-
 /* ---- L2CAP channels ---- */
 static struct sock *__l2cap_get_chan_by_dcid(struct l2cap_chan_list *l, u16 cid)
 {
@@ -292,33 +305,44 @@ static void l2cap_chan_del(struct sock *sk, int err)
        }
 }
 
-/* Service level security */
-static inline int l2cap_check_security(struct sock *sk)
+static inline u8 l2cap_get_auth_type(struct sock *sk)
 {
-       struct l2cap_conn *conn = l2cap_pi(sk)->conn;
-       __u8 auth_type;
+       if (sk->sk_type == SOCK_RAW) {
+               switch (l2cap_pi(sk)->sec_level) {
+               case BT_SECURITY_HIGH:
+                       return HCI_AT_DEDICATED_BONDING_MITM;
+               case BT_SECURITY_MEDIUM:
+                       return HCI_AT_DEDICATED_BONDING;
+               default:
+                       return HCI_AT_NO_BONDING;
+               }
+       } else if (l2cap_pi(sk)->psm == cpu_to_le16(0x0001)) {
+               if (l2cap_pi(sk)->sec_level == BT_SECURITY_LOW)
+                       l2cap_pi(sk)->sec_level = BT_SECURITY_SDP;
 
-       if (l2cap_pi(sk)->psm == cpu_to_le16(0x0001)) {
                if (l2cap_pi(sk)->sec_level == BT_SECURITY_HIGH)
-                       auth_type = HCI_AT_NO_BONDING_MITM;
+                       return HCI_AT_NO_BONDING_MITM;
                else
-                       auth_type = HCI_AT_NO_BONDING;
-
-               if (l2cap_pi(sk)->sec_level == BT_SECURITY_LOW)
-                       l2cap_pi(sk)->sec_level = BT_SECURITY_SDP;
+                       return HCI_AT_NO_BONDING;
        } else {
                switch (l2cap_pi(sk)->sec_level) {
                case BT_SECURITY_HIGH:
-                       auth_type = HCI_AT_GENERAL_BONDING_MITM;
-                       break;
+                       return HCI_AT_GENERAL_BONDING_MITM;
                case BT_SECURITY_MEDIUM:
-                       auth_type = HCI_AT_GENERAL_BONDING;
-                       break;
+                       return HCI_AT_GENERAL_BONDING;
                default:
-                       auth_type = HCI_AT_NO_BONDING;
-                       break;
+                       return HCI_AT_NO_BONDING;
                }
        }
+}
+
+/* Service level security */
+static inline int l2cap_check_security(struct sock *sk)
+{
+       struct l2cap_conn *conn = l2cap_pi(sk)->conn;
+       __u8 auth_type;
+
+       auth_type = l2cap_get_auth_type(sk);
 
        return hci_conn_security(conn->hcon, l2cap_pi(sk)->sec_level,
                                                                auth_type);
@@ -456,7 +480,23 @@ static void l2cap_do_start(struct sock *sk)
        }
 }
 
-static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct sock *sk)
+static inline int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
+{
+       u32 local_feat_mask = l2cap_feat_mask;
+       if (!disable_ertm)
+               local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
+
+       switch (mode) {
+       case L2CAP_MODE_ERTM:
+               return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
+       case L2CAP_MODE_STREAMING:
+               return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
+       default:
+               return 0x00;
+       }
+}
+
+static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct sock *sk, int err)
 {
        struct l2cap_disconn_req req;
 
@@ -477,16 +517,20 @@ static void l2cap_send_disconn_req(struct l2cap_conn *conn, struct sock *sk)
                        L2CAP_DISCONN_REQ, sizeof(req), &req);
 
        sk->sk_state = BT_DISCONN;
+       sk->sk_err = err;
 }
 
 /* ---- L2CAP connections ---- */
 static void l2cap_conn_start(struct l2cap_conn *conn)
 {
        struct l2cap_chan_list *l = &conn->chan_list;
+       struct sock_del_list del, *tmp1, *tmp2;
        struct sock *sk;
 
        BT_DBG("conn %p", conn);
 
+       INIT_LIST_HEAD(&del.list);
+
        read_lock(&l->lock);
 
        for (sk = l->head; sk; sk = l2cap_pi(sk)->next_c) {
@@ -499,20 +543,38 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
                }
 
                if (sk->sk_state == BT_CONNECT) {
-                       if (l2cap_check_security(sk) &&
-                                       __l2cap_no_conn_pending(sk)) {
-                               struct l2cap_conn_req req;
-                               req.scid = cpu_to_le16(l2cap_pi(sk)->scid);
-                               req.psm  = l2cap_pi(sk)->psm;
+                       struct l2cap_conn_req req;
 
-                               l2cap_pi(sk)->ident = l2cap_get_ident(conn);
-                               l2cap_pi(sk)->conf_state |= L2CAP_CONF_CONNECT_PEND;
+                       if (!l2cap_check_security(sk) ||
+                                       !__l2cap_no_conn_pending(sk)) {
+                               bh_unlock_sock(sk);
+                               continue;
+                       }
 
-                               l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
-                                       L2CAP_CONN_REQ, sizeof(req), &req);
+                       if (!l2cap_mode_supported(l2cap_pi(sk)->mode,
+                                       conn->feat_mask)
+                                       && l2cap_pi(sk)->conf_state &
+                                       L2CAP_CONF_STATE2_DEVICE) {
+                               tmp1 = kzalloc(sizeof(struct sock_del_list),
+                                               GFP_ATOMIC);
+                               tmp1->sk = sk;
+                               list_add_tail(&tmp1->list, &del.list);
+                               bh_unlock_sock(sk);
+                               continue;
                        }
+
+                       req.scid = cpu_to_le16(l2cap_pi(sk)->scid);
+                       req.psm  = l2cap_pi(sk)->psm;
+
+                       l2cap_pi(sk)->ident = l2cap_get_ident(conn);
+                       l2cap_pi(sk)->conf_state |= L2CAP_CONF_CONNECT_PEND;
+
+                       l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
+                               L2CAP_CONN_REQ, sizeof(req), &req);
+
                } else if (sk->sk_state == BT_CONNECT2) {
                        struct l2cap_conn_rsp rsp;
+                       char buf[128];
                        rsp.scid = cpu_to_le16(l2cap_pi(sk)->dcid);
                        rsp.dcid = cpu_to_le16(l2cap_pi(sk)->scid);
 
@@ -535,12 +597,31 @@ static void l2cap_conn_start(struct l2cap_conn *conn)
 
                        l2cap_send_cmd(conn, l2cap_pi(sk)->ident,
                                        L2CAP_CONN_RSP, sizeof(rsp), &rsp);
+
+                       if (l2cap_pi(sk)->conf_state & L2CAP_CONF_REQ_SENT ||
+                                       rsp.result != L2CAP_CR_SUCCESS) {
+                               bh_unlock_sock(sk);
+                               continue;
+                       }
+
+                       l2cap_pi(sk)->conf_state |= L2CAP_CONF_REQ_SENT;
+                       l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
+                                               l2cap_build_conf_req(sk, buf), buf);
+                       l2cap_pi(sk)->num_conf_req++;
                }
 
                bh_unlock_sock(sk);
        }
 
        read_unlock(&l->lock);
+
+       list_for_each_entry_safe(tmp1, tmp2, &del.list, list) {
+               bh_lock_sock(tmp1->sk);
+               __l2cap_sock_close(tmp1->sk, ECONNRESET);
+               bh_unlock_sock(tmp1->sk);
+               list_del(&tmp1->list);
+               kfree(tmp1);
+       }
 }
 
 static void l2cap_conn_ready(struct l2cap_conn *conn)
@@ -681,11 +762,13 @@ found:
 /* Find socket with psm and source bdaddr.
  * Returns closest match.
  */
-static struct sock *__l2cap_get_sock_by_psm(int state, __le16 psm, bdaddr_t *src)
+static struct sock *l2cap_get_sock_by_psm(int state, __le16 psm, bdaddr_t *src)
 {
        struct sock *sk = NULL, *sk1 = NULL;
        struct hlist_node *node;
 
+       read_lock(&l2cap_sk_list.lock);
+
        sk_for_each(sk, node, &l2cap_sk_list.head) {
                if (state && sk->sk_state != state)
                        continue;
@@ -700,20 +783,10 @@ static struct sock *__l2cap_get_sock_by_psm(int state, __le16 psm, bdaddr_t *src
                                sk1 = sk;
                }
        }
-       return node ? sk : sk1;
-}
 
-/* Find socket with given address (psm, src).
- * Returns locked socket */
-static inline struct sock *l2cap_get_sock_by_psm(int state, __le16 psm, bdaddr_t *src)
-{
-       struct sock *s;
-       read_lock(&l2cap_sk_list.lock);
-       s = __l2cap_get_sock_by_psm(state, psm, src);
-       if (s)
-               bh_lock_sock(s);
        read_unlock(&l2cap_sk_list.lock);
-       return s;
+
+       return node ? sk : sk1;
 }
 
 static void l2cap_sock_destruct(struct sock *sk)
@@ -770,7 +843,7 @@ static void __l2cap_sock_close(struct sock *sk, int reason)
                        struct l2cap_conn *conn = l2cap_pi(sk)->conn;
 
                        l2cap_sock_set_timer(sk, sk->sk_sndtimeo);
-                       l2cap_send_disconn_req(conn, sk);
+                       l2cap_send_disconn_req(conn, sk, reason);
                } else
                        l2cap_chan_del(sk, reason);
                break;
@@ -786,6 +859,7 @@ static void __l2cap_sock_close(struct sock *sk, int reason)
                                result = L2CAP_CR_SEC_BLOCK;
                        else
                                result = L2CAP_CR_BAD_PSM;
+                       sk->sk_state = BT_DISCONN;
 
                        rsp.scid   = cpu_to_le16(l2cap_pi(sk)->dcid);
                        rsp.dcid   = cpu_to_le16(l2cap_pi(sk)->scid);
@@ -830,6 +904,7 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent)
 
                pi->imtu = l2cap_pi(parent)->imtu;
                pi->omtu = l2cap_pi(parent)->omtu;
+               pi->conf_state = l2cap_pi(parent)->conf_state;
                pi->mode = l2cap_pi(parent)->mode;
                pi->fcs  = l2cap_pi(parent)->fcs;
                pi->max_tx = l2cap_pi(parent)->max_tx;
@@ -840,10 +915,12 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent)
        } else {
                pi->imtu = L2CAP_DEFAULT_MTU;
                pi->omtu = 0;
-               if (enable_ertm && sk->sk_type == SOCK_STREAM)
+               if (!disable_ertm && sk->sk_type == SOCK_STREAM) {
                        pi->mode = L2CAP_MODE_ERTM;
-               else
+                       pi->conf_state |= L2CAP_CONF_STATE2_DEVICE;
+               } else {
                        pi->mode = L2CAP_MODE_BASIC;
+               }
                pi->max_tx = L2CAP_DEFAULT_MAX_TX;
                pi->fcs  = L2CAP_FCS_CRC16;
                pi->tx_win = L2CAP_DEFAULT_TX_WINDOW;
@@ -943,10 +1020,20 @@ static int l2cap_sock_bind(struct socket *sock, struct sockaddr *addr, int alen)
                goto done;
        }
 
-       if (la.l2_psm && __le16_to_cpu(la.l2_psm) < 0x1001 &&
-                               !capable(CAP_NET_BIND_SERVICE)) {
-               err = -EACCES;
-               goto done;
+       if (la.l2_psm) {
+               __u16 psm = __le16_to_cpu(la.l2_psm);
+
+               /* PSM must be odd and lsb of upper byte must be 0 */
+               if ((psm & 0x0101) != 0x0001) {
+                       err = -EINVAL;
+                       goto done;
+               }
+
+               /* Restrict usage of well-known PSMs */
+               if (psm < 0x1001 && !capable(CAP_NET_BIND_SERVICE)) {
+                       err = -EACCES;
+                       goto done;
+               }
        }
 
        write_lock_bh(&l2cap_sk_list.lock);
@@ -993,39 +1080,7 @@ static int l2cap_do_connect(struct sock *sk)
 
        err = -ENOMEM;
 
-       if (sk->sk_type == SOCK_RAW) {
-               switch (l2cap_pi(sk)->sec_level) {
-               case BT_SECURITY_HIGH:
-                       auth_type = HCI_AT_DEDICATED_BONDING_MITM;
-                       break;
-               case BT_SECURITY_MEDIUM:
-                       auth_type = HCI_AT_DEDICATED_BONDING;
-                       break;
-               default:
-                       auth_type = HCI_AT_NO_BONDING;
-                       break;
-               }
-       } else if (l2cap_pi(sk)->psm == cpu_to_le16(0x0001)) {
-               if (l2cap_pi(sk)->sec_level == BT_SECURITY_HIGH)
-                       auth_type = HCI_AT_NO_BONDING_MITM;
-               else
-                       auth_type = HCI_AT_NO_BONDING;
-
-               if (l2cap_pi(sk)->sec_level == BT_SECURITY_LOW)
-                       l2cap_pi(sk)->sec_level = BT_SECURITY_SDP;
-       } else {
-               switch (l2cap_pi(sk)->sec_level) {
-               case BT_SECURITY_HIGH:
-                       auth_type = HCI_AT_GENERAL_BONDING_MITM;
-                       break;
-               case BT_SECURITY_MEDIUM:
-                       auth_type = HCI_AT_GENERAL_BONDING;
-                       break;
-               default:
-                       auth_type = HCI_AT_NO_BONDING;
-                       break;
-               }
-       }
+       auth_type = l2cap_get_auth_type(sk);
 
        hcon = hci_connect(hdev, ACL_LINK, dst,
                                        l2cap_pi(sk)->sec_level, auth_type);
@@ -1052,7 +1107,8 @@ static int l2cap_do_connect(struct sock *sk)
                if (sk->sk_type != SOCK_SEQPACKET &&
                                sk->sk_type != SOCK_STREAM) {
                        l2cap_sock_clear_timer(sk);
-                       sk->sk_state = BT_CONNECTED;
+                       if (l2cap_check_security(sk))
+                               sk->sk_state = BT_CONNECTED;
                } else
                        l2cap_do_start(sk);
        }
@@ -1095,7 +1151,7 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, int al
                break;
        case L2CAP_MODE_ERTM:
        case L2CAP_MODE_STREAMING:
-               if (enable_ertm)
+               if (!disable_ertm)
                        break;
                /* fall through */
        default:
@@ -1112,6 +1168,7 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, int al
 
        case BT_CONNECTED:
                /* Already connected */
+               err = -EISCONN;
                goto done;
 
        case BT_OPEN:
@@ -1124,6 +1181,13 @@ static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, int al
                goto done;
        }
 
+       /* PSM must be odd and lsb of upper byte must be 0 */
+       if ((__le16_to_cpu(la.l2_psm) & 0x0101) != 0x0001 &&
+               sk->sk_type != SOCK_RAW) {
+               err = -EINVAL;
+               goto done;
+       }
+
        /* Set destination address and psm */
        bacpy(&bt_sk(sk)->dst, &la.l2_bdaddr);
        l2cap_pi(sk)->psm = la.l2_psm;
@@ -1160,7 +1224,7 @@ static int l2cap_sock_listen(struct socket *sock, int backlog)
                break;
        case L2CAP_MODE_ERTM:
        case L2CAP_MODE_STREAMING:
-               if (enable_ertm)
+               if (!disable_ertm)
                        break;
                /* fall through */
        default:
@@ -1313,9 +1377,11 @@ static void l2cap_monitor_timeout(unsigned long arg)
 {
        struct sock *sk = (void *) arg;
 
+       BT_DBG("sk %p", sk);
+
        bh_lock_sock(sk);
        if (l2cap_pi(sk)->retry_count >= l2cap_pi(sk)->remote_max_tx) {
-               l2cap_send_disconn_req(l2cap_pi(sk)->conn, sk);
+               l2cap_send_disconn_req(l2cap_pi(sk)->conn, sk, ECONNABORTED);
                bh_unlock_sock(sk);
                return;
        }
@@ -1331,6 +1397,8 @@ static void l2cap_retrans_timeout(unsigned long arg)
 {
        struct sock *sk = (void *) arg;
 
+       BT_DBG("sk %p", sk);
+
        bh_lock_sock(sk);
        l2cap_pi(sk)->retry_count = 1;
        __mod_monitor_timer();
@@ -1369,37 +1437,26 @@ static inline void l2cap_do_send(struct sock *sk, struct sk_buff *skb)
        hci_send_acl(pi->conn->hcon, skb, 0);
 }
 
-static int l2cap_streaming_send(struct sock *sk)
+static void l2cap_streaming_send(struct sock *sk)
 {
-       struct sk_buff *skb, *tx_skb;
+       struct sk_buff *skb;
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        u16 control, fcs;
 
-       while ((skb = sk->sk_send_head)) {
-               tx_skb = skb_clone(skb, GFP_ATOMIC);
-
-               control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE);
+       while ((skb = skb_dequeue(TX_QUEUE(sk)))) {
+               control = get_unaligned_le16(skb->data + L2CAP_HDR_SIZE);
                control |= pi->next_tx_seq << L2CAP_CTRL_TXSEQ_SHIFT;
-               put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE);
+               put_unaligned_le16(control, skb->data + L2CAP_HDR_SIZE);
 
                if (pi->fcs == L2CAP_FCS_CRC16) {
-                       fcs = crc16(0, (u8 *)tx_skb->data, tx_skb->len - 2);
-                       put_unaligned_le16(fcs, tx_skb->data + tx_skb->len - 2);
+                       fcs = crc16(0, (u8 *)skb->data, skb->len - 2);
+                       put_unaligned_le16(fcs, skb->data + skb->len - 2);
                }
 
-               l2cap_do_send(sk, tx_skb);
+               l2cap_do_send(sk, skb);
 
                pi->next_tx_seq = (pi->next_tx_seq + 1) % 64;
-
-               if (skb_queue_is_last(TX_QUEUE(sk), skb))
-                       sk->sk_send_head = NULL;
-               else
-                       sk->sk_send_head = skb_queue_next(TX_QUEUE(sk), skb);
-
-               skb = skb_dequeue(TX_QUEUE(sk));
-               kfree_skb(skb);
        }
-       return 0;
 }
 
 static void l2cap_retransmit_one_frame(struct sock *sk, u8 tx_seq)
@@ -1423,17 +1480,22 @@ static void l2cap_retransmit_one_frame(struct sock *sk, u8 tx_seq)
 
        if (pi->remote_max_tx &&
                        bt_cb(skb)->retries == pi->remote_max_tx) {
-               l2cap_send_disconn_req(pi->conn, sk);
+               l2cap_send_disconn_req(pi->conn, sk, ECONNABORTED);
                return;
        }
 
        tx_skb = skb_clone(skb, GFP_ATOMIC);
        bt_cb(skb)->retries++;
        control = get_unaligned_le16(tx_skb->data + L2CAP_HDR_SIZE);
-       control &= L2CAP_CTRL_SAR;
+
+       if (pi->conn_state & L2CAP_CONN_SEND_FBIT) {
+               control |= L2CAP_CTRL_FINAL;
+               pi->conn_state &= ~L2CAP_CONN_SEND_FBIT;
+       }
 
        control |= (pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT)
                        | (tx_seq << L2CAP_CTRL_TXSEQ_SHIFT);
+
        put_unaligned_le16(control, tx_skb->data + L2CAP_HDR_SIZE);
 
        if (pi->fcs == L2CAP_FCS_CRC16) {
@@ -1458,7 +1520,7 @@ static int l2cap_ertm_send(struct sock *sk)
 
                if (pi->remote_max_tx &&
                                bt_cb(skb)->retries == pi->remote_max_tx) {
-                       l2cap_send_disconn_req(pi->conn, sk);
+                       l2cap_send_disconn_req(pi->conn, sk, ECONNABORTED);
                        break;
                }
 
@@ -1509,16 +1571,11 @@ static int l2cap_retransmit_frames(struct sock *sk)
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        int ret;
 
-       spin_lock_bh(&pi->send_lock);
-
        if (!skb_queue_empty(TX_QUEUE(sk)))
                sk->sk_send_head = TX_QUEUE(sk)->next;
 
        pi->next_tx_seq = pi->expected_ack_seq;
        ret = l2cap_ertm_send(sk);
-
-       spin_unlock_bh(&pi->send_lock);
-
        return ret;
 }
 
@@ -1526,7 +1583,6 @@ static void l2cap_send_ack(struct l2cap_pinfo *pi)
 {
        struct sock *sk = (struct sock *)pi;
        u16 control = 0;
-       int nframes;
 
        control |= pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT;
 
@@ -1537,11 +1593,7 @@ static void l2cap_send_ack(struct l2cap_pinfo *pi)
                return;
        }
 
-       spin_lock_bh(&pi->send_lock);
-       nframes = l2cap_ertm_send(sk);
-       spin_unlock_bh(&pi->send_lock);
-
-       if (nframes > 0)
+       if (l2cap_ertm_send(sk) > 0)
                return;
 
        control |= L2CAP_SUPER_RCV_READY;
@@ -1581,7 +1633,7 @@ static inline int l2cap_skbuff_fromiovec(struct sock *sk, struct msghdr *msg, in
 
                *frag = bt_skb_send_alloc(sk, count, msg->msg_flags & MSG_DONTWAIT, &err);
                if (!*frag)
-                       return -EFAULT;
+                       return err;
                if (memcpy_fromiovec(skb_put(*frag, count), msg->msg_iov, count))
                        return -EFAULT;
 
@@ -1607,7 +1659,7 @@ static struct sk_buff *l2cap_create_connless_pdu(struct sock *sk, struct msghdr
        skb = bt_skb_send_alloc(sk, count + hlen,
                        msg->msg_flags & MSG_DONTWAIT, &err);
        if (!skb)
-               return ERR_PTR(-ENOMEM);
+               return ERR_PTR(err);
 
        /* Create L2CAP header */
        lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
@@ -1636,7 +1688,7 @@ static struct sk_buff *l2cap_create_basic_pdu(struct sock *sk, struct msghdr *ms
        skb = bt_skb_send_alloc(sk, count + hlen,
                        msg->msg_flags & MSG_DONTWAIT, &err);
        if (!skb)
-               return ERR_PTR(-ENOMEM);
+               return ERR_PTR(err);
 
        /* Create L2CAP header */
        lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
@@ -1673,7 +1725,7 @@ static struct sk_buff *l2cap_create_iframe_pdu(struct sock *sk, struct msghdr *m
        skb = bt_skb_send_alloc(sk, count + hlen,
                        msg->msg_flags & MSG_DONTWAIT, &err);
        if (!skb)
-               return ERR_PTR(-ENOMEM);
+               return ERR_PTR(err);
 
        /* Create L2CAP header */
        lh = (struct l2cap_hdr *) skb_put(skb, L2CAP_HDR_SIZE);
@@ -1736,10 +1788,8 @@ static inline int l2cap_sar_segment_sdu(struct sock *sk, struct msghdr *msg, siz
                size += buflen;
        }
        skb_queue_splice_tail(&sar_queue, TX_QUEUE(sk));
-       spin_lock_bh(&pi->send_lock);
        if (sk->sk_send_head == NULL)
                sk->sk_send_head = sar_queue.next;
-       spin_unlock_bh(&pi->send_lock);
 
        return size;
 }
@@ -1784,7 +1834,7 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
        case L2CAP_MODE_BASIC:
                /* Check outgoing MTU */
                if (len > pi->omtu) {
-                       err = -EINVAL;
+                       err = -EMSGSIZE;
                        goto done;
                }
 
@@ -1811,14 +1861,9 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
                        }
                        __skb_queue_tail(TX_QUEUE(sk), skb);
 
-                       if (pi->mode == L2CAP_MODE_ERTM)
-                               spin_lock_bh(&pi->send_lock);
-
                        if (sk->sk_send_head == NULL)
                                sk->sk_send_head = skb;
 
-                       if (pi->mode == L2CAP_MODE_ERTM)
-                               spin_unlock_bh(&pi->send_lock);
                } else {
                /* Segment SDU into multiples PDUs */
                        err = l2cap_sar_segment_sdu(sk, msg, len);
@@ -1827,16 +1872,14 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
                }
 
                if (pi->mode == L2CAP_MODE_STREAMING) {
-                       err = l2cap_streaming_send(sk);
+                       l2cap_streaming_send(sk);
                } else {
-                       if (pi->conn_state & L2CAP_CONN_REMOTE_BUSY &&
-                                       pi->conn_state && L2CAP_CONN_WAIT_F) {
+                       if ((pi->conn_state & L2CAP_CONN_REMOTE_BUSY) &&
+                                       (pi->conn_state & L2CAP_CONN_WAIT_F)) {
                                err = len;
                                break;
                        }
-                       spin_lock_bh(&pi->send_lock);
                        err = l2cap_ertm_send(sk);
-                       spin_unlock_bh(&pi->send_lock);
                }
 
                if (err >= 0)
@@ -1845,7 +1888,7 @@ static int l2cap_sock_sendmsg(struct kiocb *iocb, struct socket *sock, struct ms
 
        default:
                BT_DBG("bad state %1.1x", pi->mode);
-               err = -EINVAL;
+               err = -EBADFD;
        }
 
 done:
@@ -1861,6 +1904,8 @@ static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct ms
 
        if (sk->sk_state == BT_CONNECT2 && bt_sk(sk)->defer_setup) {
                struct l2cap_conn_rsp rsp;
+               struct l2cap_conn *conn = l2cap_pi(sk)->conn;
+               u8 buf[128];
 
                sk->sk_state = BT_CONFIG;
 
@@ -1871,12 +1916,25 @@ static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct ms
                l2cap_send_cmd(l2cap_pi(sk)->conn, l2cap_pi(sk)->ident,
                                        L2CAP_CONN_RSP, sizeof(rsp), &rsp);
 
+               if (l2cap_pi(sk)->conf_state & L2CAP_CONF_REQ_SENT) {
+                       release_sock(sk);
+                       return 0;
+               }
+
+               l2cap_pi(sk)->conf_state |= L2CAP_CONF_REQ_SENT;
+               l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
+                               l2cap_build_conf_req(sk, buf), buf);
+               l2cap_pi(sk)->num_conf_req++;
+
                release_sock(sk);
                return 0;
        }
 
        release_sock(sk);
 
+       if (sock->type == SOCK_STREAM)
+               return bt_sock_stream_recvmsg(iocb, sock, msg, len, flags);
+
        return bt_sock_recvmsg(iocb, sock, msg, len, flags);
 }
 
@@ -1893,6 +1951,11 @@ static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __us
 
        switch (optname) {
        case L2CAP_OPTIONS:
+               if (sk->sk_state == BT_CONNECTED) {
+                       err = -EINVAL;
+                       break;
+               }
+
                opts.imtu     = l2cap_pi(sk)->imtu;
                opts.omtu     = l2cap_pi(sk)->omtu;
                opts.flush_to = l2cap_pi(sk)->flush_to;
@@ -1907,13 +1970,19 @@ static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __us
                        break;
                }
 
+               if (opts.txwin_size > L2CAP_DEFAULT_TX_WINDOW) {
+                       err = -EINVAL;
+                       break;
+               }
+
                l2cap_pi(sk)->mode = opts.mode;
                switch (l2cap_pi(sk)->mode) {
                case L2CAP_MODE_BASIC:
+                       l2cap_pi(sk)->conf_state &= ~L2CAP_CONF_STATE2_DEVICE;
                        break;
                case L2CAP_MODE_ERTM:
                case L2CAP_MODE_STREAMING:
-                       if (enable_ertm)
+                       if (!disable_ertm)
                                break;
                        /* fall through */
                default:
@@ -2085,6 +2154,7 @@ static int l2cap_sock_getsockopt_old(struct socket *sock, int optname, char __us
                        break;
                }
 
+               memset(&cinfo, 0, sizeof(cinfo));
                cinfo.hci_handle = l2cap_pi(sk)->conn->hcon->handle;
                memcpy(cinfo.dev_class, l2cap_pi(sk)->conn->hcon->dev_class, 3);
 
@@ -2181,6 +2251,10 @@ static int l2cap_sock_shutdown(struct socket *sock, int how)
                        err = bt_sock_wait_state(sk, BT_CLOSED,
                                                        sk->sk_lingertime);
        }
+
+       if (!err && sk->sk_err)
+               err = -sk->sk_err;
+
        release_sock(sk);
        return err;
 }
@@ -2329,11 +2403,11 @@ static inline int l2cap_get_conf_opt(void **ptr, int *type, int *olen, unsigned
                break;
 
        case 2:
-               *val = __le16_to_cpu(*((__le16 *) opt->val));
+               *val = get_unaligned_le16(opt->val);
                break;
 
        case 4:
-               *val = __le32_to_cpu(*((__le32 *) opt->val));
+               *val = get_unaligned_le32(opt->val);
                break;
 
        default:
@@ -2360,11 +2434,11 @@ static void l2cap_add_conf_opt(void **ptr, u8 type, u8 len, unsigned long val)
                break;
 
        case 2:
-               *((__le16 *) opt->val) = cpu_to_le16(val);
+               put_unaligned_le16(val, opt->val);
                break;
 
        case 4:
-               *((__le32 *) opt->val) = cpu_to_le32(val);
+               put_unaligned_le32(val, opt->val);
                break;
 
        default:
@@ -2401,25 +2475,10 @@ static inline void l2cap_ertm_init(struct sock *sk)
 
        __skb_queue_head_init(SREJ_QUEUE(sk));
        __skb_queue_head_init(BUSY_QUEUE(sk));
-       spin_lock_init(&l2cap_pi(sk)->send_lock);
 
        INIT_WORK(&l2cap_pi(sk)->busy_work, l2cap_busy_work);
-}
-
-static int l2cap_mode_supported(__u8 mode, __u32 feat_mask)
-{
-       u32 local_feat_mask = l2cap_feat_mask;
-       if (enable_ertm)
-               local_feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING;
 
-       switch (mode) {
-       case L2CAP_MODE_ERTM:
-               return L2CAP_FEAT_ERTM & feat_mask & local_feat_mask;
-       case L2CAP_MODE_STREAMING:
-               return L2CAP_FEAT_STREAMING & feat_mask & local_feat_mask;
-       default:
-               return 0x00;
-       }
+       sk->sk_backlog_rcv = l2cap_ertm_data_rcv;
 }
 
 static inline __u8 l2cap_select_mode(__u8 mode, __u16 remote_feat_mask)
@@ -2450,10 +2509,10 @@ static int l2cap_build_conf_req(struct sock *sk, void *data)
        switch (pi->mode) {
        case L2CAP_MODE_STREAMING:
        case L2CAP_MODE_ERTM:
-               pi->conf_state |= L2CAP_CONF_STATE2_DEVICE;
-               if (!l2cap_mode_supported(pi->mode, pi->conn->feat_mask))
-                       l2cap_send_disconn_req(pi->conn, sk);
-               break;
+               if (pi->conf_state & L2CAP_CONF_STATE2_DEVICE)
+                       break;
+
+               /* fall through */
        default:
                pi->mode = l2cap_select_mode(rfc.mode, pi->conn->feat_mask);
                break;
@@ -2464,6 +2523,20 @@ done:
        case L2CAP_MODE_BASIC:
                if (pi->imtu != L2CAP_DEFAULT_MTU)
                        l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, pi->imtu);
+
+               if (!(pi->conn->feat_mask & L2CAP_FEAT_ERTM) &&
+                               !(pi->conn->feat_mask & L2CAP_FEAT_STREAMING))
+                       break;
+
+               rfc.mode            = L2CAP_MODE_BASIC;
+               rfc.txwin_size      = 0;
+               rfc.max_transmit    = 0;
+               rfc.retrans_timeout = 0;
+               rfc.monitor_timeout = 0;
+               rfc.max_pdu_size    = 0;
+
+               l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
+                                                       (unsigned long) &rfc);
                break;
 
        case L2CAP_MODE_ERTM:
@@ -2476,8 +2549,8 @@ done:
                if (L2CAP_DEFAULT_MAX_PDU_SIZE > pi->conn->mtu - 10)
                        rfc.max_pdu_size = cpu_to_le16(pi->conn->mtu - 10);
 
-               l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
-                                       sizeof(rfc), (unsigned long) &rfc);
+               l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
+                                                       (unsigned long) &rfc);
 
                if (!(pi->conn->feat_mask & L2CAP_FEAT_FCS))
                        break;
@@ -2499,8 +2572,8 @@ done:
                if (L2CAP_DEFAULT_MAX_PDU_SIZE > pi->conn->mtu - 10)
                        rfc.max_pdu_size = cpu_to_le16(pi->conn->mtu - 10);
 
-               l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
-                                       sizeof(rfc), (unsigned long) &rfc);
+               l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc),
+                                                       (unsigned long) &rfc);
 
                if (!(pi->conn->feat_mask & L2CAP_FEAT_FCS))
                        break;
@@ -2577,18 +2650,21 @@ static int l2cap_parse_conf_req(struct sock *sk, void *data)
                }
        }
 
-       if (pi->num_conf_rsp || pi->num_conf_req)
+       if (pi->num_conf_rsp || pi->num_conf_req > 1)
                goto done;
 
        switch (pi->mode) {
        case L2CAP_MODE_STREAMING:
        case L2CAP_MODE_ERTM:
-               pi->conf_state |= L2CAP_CONF_STATE2_DEVICE;
-               if (!l2cap_mode_supported(pi->mode, pi->conn->feat_mask))
+               if (!(pi->conf_state & L2CAP_CONF_STATE2_DEVICE)) {
+                       pi->mode = l2cap_select_mode(rfc.mode,
+                                       pi->conn->feat_mask);
+                       break;
+               }
+
+               if (pi->mode != rfc.mode)
                        return -ECONNREFUSED;
-               break;
-       default:
-               pi->mode = l2cap_select_mode(rfc.mode, pi->conn->feat_mask);
+
                break;
        }
 
@@ -2626,8 +2702,9 @@ done:
                case L2CAP_MODE_ERTM:
                        pi->remote_tx_win = rfc.txwin_size;
                        pi->remote_max_tx = rfc.max_transmit;
-                       if (rfc.max_pdu_size > pi->conn->mtu - 10)
-                               rfc.max_pdu_size = le16_to_cpu(pi->conn->mtu - 10);
+
+                       if (le16_to_cpu(rfc.max_pdu_size) > pi->conn->mtu - 10)
+                               rfc.max_pdu_size = cpu_to_le16(pi->conn->mtu - 10);
 
                        pi->remote_mps = le16_to_cpu(rfc.max_pdu_size);
 
@@ -2644,8 +2721,8 @@ done:
                        break;
 
                case L2CAP_MODE_STREAMING:
-                       if (rfc.max_pdu_size > pi->conn->mtu - 10)
-                               rfc.max_pdu_size = le16_to_cpu(pi->conn->mtu - 10);
+                       if (le16_to_cpu(rfc.max_pdu_size) > pi->conn->mtu - 10)
+                               rfc.max_pdu_size = cpu_to_le16(pi->conn->mtu - 10);
 
                        pi->remote_mps = le16_to_cpu(rfc.max_pdu_size);
 
@@ -2691,10 +2768,10 @@ static int l2cap_parse_conf_rsp(struct sock *sk, void *rsp, int len, void *data,
                case L2CAP_CONF_MTU:
                        if (val < L2CAP_DEFAULT_MIN_MTU) {
                                *result = L2CAP_CONF_UNACCEPT;
-                               pi->omtu = L2CAP_DEFAULT_MIN_MTU;
+                               pi->imtu = L2CAP_DEFAULT_MIN_MTU;
                        } else
-                               pi->omtu = val;
-                       l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, pi->omtu);
+                               pi->imtu = val;
+                       l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, pi->imtu);
                        break;
 
                case L2CAP_CONF_FLUSH_TO:
@@ -2711,7 +2788,6 @@ static int l2cap_parse_conf_rsp(struct sock *sk, void *rsp, int len, void *data,
                                                        rfc.mode != pi->mode)
                                return -ECONNREFUSED;
 
-                       pi->mode = rfc.mode;
                        pi->fcs = 0;
 
                        l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
@@ -2720,10 +2796,14 @@ static int l2cap_parse_conf_rsp(struct sock *sk, void *rsp, int len, void *data,
                }
        }
 
+       if (pi->mode == L2CAP_MODE_BASIC && pi->mode != rfc.mode)
+               return -ECONNREFUSED;
+
+       pi->mode = rfc.mode;
+
        if (*result == L2CAP_CONF_SUCCESS) {
                switch (rfc.mode) {
                case L2CAP_MODE_ERTM:
-                       pi->remote_tx_win   = rfc.txwin_size;
                        pi->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
                        pi->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
                        pi->mps    = le16_to_cpu(rfc.max_pdu_size);
@@ -2779,7 +2859,6 @@ static void l2cap_conf_rfc_get(struct sock *sk, void *rsp, int len)
 done:
        switch (rfc.mode) {
        case L2CAP_MODE_ERTM:
-               pi->remote_tx_win   = rfc.txwin_size;
                pi->retrans_timeout = le16_to_cpu(rfc.retrans_timeout);
                pi->monitor_timeout = le16_to_cpu(rfc.monitor_timeout);
                pi->mps    = le16_to_cpu(rfc.max_pdu_size);
@@ -2814,7 +2893,7 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
        struct l2cap_chan_list *list = &conn->chan_list;
        struct l2cap_conn_req *req = (struct l2cap_conn_req *) data;
        struct l2cap_conn_rsp rsp;
-       struct sock *sk, *parent;
+       struct sock *parent, *sk = NULL;
        int result, status = L2CAP_CS_NO_INFO;
 
        u16 dcid = 0, scid = __le16_to_cpu(req->scid);
@@ -2829,6 +2908,8 @@ static inline int l2cap_connect_req(struct l2cap_conn *conn, struct l2cap_cmd_hd
                goto sendresp;
        }
 
+       bh_lock_sock(parent);
+
        /* Check if the ACL is secure enough (if not SDP) */
        if (psm != cpu_to_le16(0x0001) &&
                                !hci_conn_check_link_mode(conn->hcon)) {
@@ -2923,6 +3004,15 @@ sendresp:
                                        L2CAP_INFO_REQ, sizeof(info), &info);
        }
 
+       if (sk && !(l2cap_pi(sk)->conf_state & L2CAP_CONF_REQ_SENT) &&
+                               result == L2CAP_CR_SUCCESS) {
+               u8 buf[128];
+               l2cap_pi(sk)->conf_state |= L2CAP_CONF_REQ_SENT;
+               l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
+                                       l2cap_build_conf_req(sk, buf), buf);
+               l2cap_pi(sk)->num_conf_req++;
+       }
+
        return 0;
 }
 
@@ -2943,11 +3033,11 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
        if (scid) {
                sk = l2cap_get_chan_by_scid(&conn->chan_list, scid);
                if (!sk)
-                       return 0;
+                       return -EFAULT;
        } else {
                sk = l2cap_get_chan_by_ident(&conn->chan_list, cmd->ident);
                if (!sk)
-                       return 0;
+                       return -EFAULT;
        }
 
        switch (result) {
@@ -2955,9 +3045,13 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
                sk->sk_state = BT_CONFIG;
                l2cap_pi(sk)->ident = 0;
                l2cap_pi(sk)->dcid = dcid;
-               l2cap_pi(sk)->conf_state |= L2CAP_CONF_REQ_SENT;
                l2cap_pi(sk)->conf_state &= ~L2CAP_CONF_CONNECT_PEND;
 
+               if (l2cap_pi(sk)->conf_state & L2CAP_CONF_REQ_SENT)
+                       break;
+
+               l2cap_pi(sk)->conf_state |= L2CAP_CONF_REQ_SENT;
+
                l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
                                        l2cap_build_conf_req(sk, req), req);
                l2cap_pi(sk)->num_conf_req++;
@@ -2968,6 +3062,14 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
                break;
 
        default:
+               /* don't delete l2cap channel if sk is owned by user */
+               if (sock_owned_by_user(sk)) {
+                       sk->sk_state = BT_DISCONN;
+                       l2cap_sock_clear_timer(sk);
+                       l2cap_sock_set_timer(sk, HZ / 5);
+                       break;
+               }
+
                l2cap_chan_del(sk, ECONNREFUSED);
                break;
        }
@@ -2976,6 +3078,17 @@ static inline int l2cap_connect_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hd
        return 0;
 }
 
+static inline void set_default_fcs(struct l2cap_pinfo *pi)
+{
+       /* FCS is enabled only in ERTM or streaming mode, if one or both
+        * sides request it.
+        */
+       if (pi->mode != L2CAP_MODE_ERTM && pi->mode != L2CAP_MODE_STREAMING)
+               pi->fcs = L2CAP_FCS_NONE;
+       else if (!(pi->conf_state & L2CAP_CONF_NO_FCS_RECV))
+               pi->fcs = L2CAP_FCS_CRC16;
+}
+
 static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr *cmd, u16 cmd_len, u8 *data)
 {
        struct l2cap_conf_req *req = (struct l2cap_conf_req *) data;
@@ -2993,12 +3106,18 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
        if (!sk)
                return -ENOENT;
 
-       if (sk->sk_state == BT_DISCONN)
+       if (sk->sk_state != BT_CONFIG) {
+               struct l2cap_cmd_rej rej;
+
+               rej.reason = cpu_to_le16(0x0002);
+               l2cap_send_cmd(conn, cmd->ident, L2CAP_COMMAND_REJ,
+                               sizeof(rej), &rej);
                goto unlock;
+       }
 
        /* Reject if config buffer is too small. */
        len = cmd_len - sizeof(*req);
-       if (l2cap_pi(sk)->conf_len + len > sizeof(l2cap_pi(sk)->conf_req)) {
+       if (len < 0 || l2cap_pi(sk)->conf_len + len > sizeof(l2cap_pi(sk)->conf_req)) {
                l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP,
                                l2cap_build_conf_rsp(sk, rsp,
                                        L2CAP_CONF_REJECT, flags), rsp);
@@ -3020,7 +3139,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
        /* Complete config. */
        len = l2cap_parse_conf_req(sk, rsp);
        if (len < 0) {
-               l2cap_send_disconn_req(conn, sk);
+               l2cap_send_disconn_req(conn, sk, ECONNRESET);
                goto unlock;
        }
 
@@ -3034,9 +3153,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
                goto unlock;
 
        if (l2cap_pi(sk)->conf_state & L2CAP_CONF_INPUT_DONE) {
-               if (!(l2cap_pi(sk)->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
-                   l2cap_pi(sk)->fcs != L2CAP_FCS_NONE)
-                       l2cap_pi(sk)->fcs = L2CAP_FCS_CRC16;
+               set_default_fcs(l2cap_pi(sk));
 
                sk->sk_state = BT_CONNECTED;
 
@@ -3052,6 +3169,7 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, struct l2cap_cmd_hdr
 
        if (!(l2cap_pi(sk)->conf_state & L2CAP_CONF_REQ_SENT)) {
                u8 buf[64];
+               l2cap_pi(sk)->conf_state |= L2CAP_CONF_REQ_SENT;
                l2cap_send_cmd(conn, l2cap_get_ident(conn), L2CAP_CONF_REQ,
                                        l2cap_build_conf_req(sk, buf), buf);
                l2cap_pi(sk)->num_conf_req++;
@@ -3090,7 +3208,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
                        char req[64];
 
                        if (len > sizeof(req) - sizeof(struct l2cap_conf_req)) {
-                               l2cap_send_disconn_req(conn, sk);
+                               l2cap_send_disconn_req(conn, sk, ECONNRESET);
                                goto done;
                        }
 
@@ -3099,7 +3217,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
                        len = l2cap_parse_conf_rsp(sk, rsp->data,
                                                        len, req, &result);
                        if (len < 0) {
-                               l2cap_send_disconn_req(conn, sk);
+                               l2cap_send_disconn_req(conn, sk, ECONNRESET);
                                goto done;
                        }
 
@@ -3114,7 +3232,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
        default:
                sk->sk_err = ECONNRESET;
                l2cap_sock_set_timer(sk, HZ * 5);
-               l2cap_send_disconn_req(conn, sk);
+               l2cap_send_disconn_req(conn, sk, ECONNRESET);
                goto done;
        }
 
@@ -3124,9 +3242,7 @@ static inline int l2cap_config_rsp(struct l2cap_conn *conn, struct l2cap_cmd_hdr
        l2cap_pi(sk)->conf_state |= L2CAP_CONF_INPUT_DONE;
 
        if (l2cap_pi(sk)->conf_state & L2CAP_CONF_OUTPUT_DONE) {
-               if (!(l2cap_pi(sk)->conf_state & L2CAP_CONF_NO_FCS_RECV) ||
-                   l2cap_pi(sk)->fcs != L2CAP_FCS_NONE)
-                       l2cap_pi(sk)->fcs = L2CAP_FCS_CRC16;
+               set_default_fcs(l2cap_pi(sk));
 
                sk->sk_state = BT_CONNECTED;
                l2cap_pi(sk)->next_tx_seq = 0;
@@ -3165,6 +3281,15 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn, struct l2cap_cmd
 
        sk->sk_shutdown = SHUTDOWN_MASK;
 
+       /* don't delete l2cap channel if sk is owned by user */
+       if (sock_owned_by_user(sk)) {
+               sk->sk_state = BT_DISCONN;
+               l2cap_sock_clear_timer(sk);
+               l2cap_sock_set_timer(sk, HZ / 5);
+               bh_unlock_sock(sk);
+               return 0;
+       }
+
        l2cap_chan_del(sk, ECONNRESET);
        bh_unlock_sock(sk);
 
@@ -3187,6 +3312,15 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn, struct l2cap_cmd
        if (!sk)
                return 0;
 
+       /* don't delete l2cap channel if sk is owned by user */
+       if (sock_owned_by_user(sk)) {
+               sk->sk_state = BT_DISCONN;
+               l2cap_sock_clear_timer(sk);
+               l2cap_sock_set_timer(sk, HZ / 5);
+               bh_unlock_sock(sk);
+               return 0;
+       }
+
        l2cap_chan_del(sk, 0);
        bh_unlock_sock(sk);
 
@@ -3209,7 +3343,7 @@ static inline int l2cap_information_req(struct l2cap_conn *conn, struct l2cap_cm
                struct l2cap_info_rsp *rsp = (struct l2cap_info_rsp *) buf;
                rsp->type   = cpu_to_le16(L2CAP_IT_FEAT_MASK);
                rsp->result = cpu_to_le16(L2CAP_IR_SUCCESS);
-               if (enable_ertm)
+               if (!disable_ertm)
                        feat_mask |= L2CAP_FEAT_ERTM | L2CAP_FEAT_STREAMING
                                                         | L2CAP_FEAT_FCS;
                put_unaligned_le32(feat_mask, rsp->data);
@@ -3246,6 +3380,15 @@ static inline int l2cap_information_rsp(struct l2cap_conn *conn, struct l2cap_cm
 
        del_timer(&conn->info_timer);
 
+       if (result != L2CAP_IR_SUCCESS) {
+               conn->info_state |= L2CAP_INFO_FEAT_MASK_REQ_DONE;
+               conn->info_ident = 0;
+
+               l2cap_conn_start(conn);
+
+               return 0;
+       }
+
        if (type == L2CAP_IT_FEAT_MASK) {
                conn->feat_mask = get_unaligned_le32(rsp->data);
 
@@ -3374,7 +3517,7 @@ static int l2cap_check_fcs(struct l2cap_pinfo *pi,  struct sk_buff *skb)
                our_fcs = crc16(0, skb->data - hdr_size, skb->len + hdr_size);
 
                if (our_fcs != rcv_fcs)
-                       return -EINVAL;
+                       return -EBADMSG;
        }
        return 0;
 }
@@ -3385,23 +3528,19 @@ static inline void l2cap_send_i_or_rr_or_rnr(struct sock *sk)
        u16 control = 0;
 
        pi->frames_sent = 0;
-       pi->conn_state |= L2CAP_CONN_SEND_FBIT;
 
        control |= pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT;
 
        if (pi->conn_state & L2CAP_CONN_LOCAL_BUSY) {
-               control |= L2CAP_SUPER_RCV_NOT_READY | L2CAP_CTRL_FINAL;
+               control |= L2CAP_SUPER_RCV_NOT_READY;
                l2cap_send_sframe(pi, control);
                pi->conn_state |= L2CAP_CONN_RNR_SENT;
-               pi->conn_state &= ~L2CAP_CONN_SEND_FBIT;
        }
 
-       if (pi->conn_state & L2CAP_CONN_REMOTE_BUSY && pi->unacked_frames > 0)
-               __mod_retrans_timer();
+       if (pi->conn_state & L2CAP_CONN_REMOTE_BUSY)
+               l2cap_retransmit_frames(sk);
 
-       spin_lock_bh(&pi->send_lock);
        l2cap_ertm_send(sk);
-       spin_unlock_bh(&pi->send_lock);
 
        if (!(pi->conn_state & L2CAP_CONN_LOCAL_BUSY) &&
                        pi->frames_sent == 0) {
@@ -3556,11 +3695,51 @@ drop:
        pi->sdu = NULL;
 
 disconnect:
-       l2cap_send_disconn_req(pi->conn, sk);
+       l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
        kfree_skb(skb);
        return 0;
 }
 
+static int l2cap_try_push_rx_skb(struct sock *sk)
+{
+       struct l2cap_pinfo *pi = l2cap_pi(sk);
+       struct sk_buff *skb;
+       u16 control;
+       int err;
+
+       while ((skb = skb_dequeue(BUSY_QUEUE(sk)))) {
+               control = bt_cb(skb)->sar << L2CAP_CTRL_SAR_SHIFT;
+               err = l2cap_ertm_reassembly_sdu(sk, skb, control);
+               if (err < 0) {
+                       skb_queue_head(BUSY_QUEUE(sk), skb);
+                       return -EBUSY;
+               }
+
+               pi->buffer_seq = (pi->buffer_seq + 1) % 64;
+       }
+
+       if (!(pi->conn_state & L2CAP_CONN_RNR_SENT))
+               goto done;
+
+       control = pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT;
+       control |= L2CAP_SUPER_RCV_READY | L2CAP_CTRL_POLL;
+       l2cap_send_sframe(pi, control);
+       l2cap_pi(sk)->retry_count = 1;
+
+       del_timer(&pi->retrans_timer);
+       __mod_monitor_timer();
+
+       l2cap_pi(sk)->conn_state |= L2CAP_CONN_WAIT_F;
+
+done:
+       pi->conn_state &= ~L2CAP_CONN_LOCAL_BUSY;
+       pi->conn_state &= ~L2CAP_CONN_RNR_SENT;
+
+       BT_DBG("sk %p, Exit local busy", sk);
+
+       return 0;
+}
+
 static void l2cap_busy_work(struct work_struct *work)
 {
        DECLARE_WAITQUEUE(wait, current);
@@ -3569,7 +3748,6 @@ static void l2cap_busy_work(struct work_struct *work)
        struct sock *sk = (struct sock *)pi;
        int n_tries = 0, timeo = HZ/5, err;
        struct sk_buff *skb;
-       u16 control;
 
        lock_sock(sk);
 
@@ -3579,8 +3757,8 @@ static void l2cap_busy_work(struct work_struct *work)
 
                if (n_tries++ > L2CAP_LOCAL_BUSY_TRIES) {
                        err = -EBUSY;
-                       l2cap_send_disconn_req(pi->conn, sk);
-                       goto done;
+                       l2cap_send_disconn_req(pi->conn, sk, EBUSY);
+                       break;
                }
 
                if (!timeo)
@@ -3588,7 +3766,7 @@ static void l2cap_busy_work(struct work_struct *work)
 
                if (signal_pending(current)) {
                        err = sock_intr_errno(timeo);
-                       goto done;
+                       break;
                }
 
                release_sock(sk);
@@ -3597,40 +3775,12 @@ static void l2cap_busy_work(struct work_struct *work)
 
                err = sock_error(sk);
                if (err)
-                       goto done;
-
-               while ((skb = skb_dequeue(BUSY_QUEUE(sk)))) {
-                       control = bt_cb(skb)->sar << L2CAP_CTRL_SAR_SHIFT;
-                       err = l2cap_ertm_reassembly_sdu(sk, skb, control);
-                       if (err < 0) {
-                               skb_queue_head(BUSY_QUEUE(sk), skb);
-                               break;
-                       }
-
-                       pi->buffer_seq = (pi->buffer_seq + 1) % 64;
-               }
+                       break;
 
-               if (!skb)
+               if (l2cap_try_push_rx_skb(sk) == 0)
                        break;
        }
 
-       if (!(pi->conn_state & L2CAP_CONN_RNR_SENT))
-               goto done;
-
-       control = pi->buffer_seq << L2CAP_CTRL_REQSEQ_SHIFT;
-       control |= L2CAP_SUPER_RCV_READY | L2CAP_CTRL_POLL;
-       l2cap_send_sframe(pi, control);
-       l2cap_pi(sk)->retry_count = 1;
-
-       del_timer(&pi->retrans_timer);
-       __mod_monitor_timer();
-
-       l2cap_pi(sk)->conn_state |= L2CAP_CONN_WAIT_F;
-
-done:
-       pi->conn_state &= ~L2CAP_CONN_LOCAL_BUSY;
-       pi->conn_state &= ~L2CAP_CONN_RNR_SENT;
-
        set_current_state(TASK_RUNNING);
        remove_wait_queue(sk_sleep(sk), &wait);
 
@@ -3645,7 +3795,9 @@ static int l2cap_push_rx_skb(struct sock *sk, struct sk_buff *skb, u16 control)
        if (pi->conn_state & L2CAP_CONN_LOCAL_BUSY) {
                bt_cb(skb)->sar = control >> L2CAP_CTRL_SAR_SHIFT;
                __skb_queue_tail(BUSY_QUEUE(sk), skb);
-               return -EBUSY;
+               return l2cap_try_push_rx_skb(sk);
+
+
        }
 
        err = l2cap_ertm_reassembly_sdu(sk, skb, control);
@@ -3655,6 +3807,8 @@ static int l2cap_push_rx_skb(struct sock *sk, struct sk_buff *skb, u16 control)
        }
 
        /* Busy Condition */
+       BT_DBG("sk %p, Enter local busy", sk);
+
        pi->conn_state |= L2CAP_CONN_LOCAL_BUSY;
        bt_cb(skb)->sar = control >> L2CAP_CTRL_SAR_SHIFT;
        __skb_queue_tail(BUSY_QUEUE(sk), skb);
@@ -3665,6 +3819,8 @@ static int l2cap_push_rx_skb(struct sock *sk, struct sk_buff *skb, u16 control)
 
        pi->conn_state |= L2CAP_CONN_RNR_SENT;
 
+       del_timer(&pi->ack_timer);
+
        queue_work(_busy_wq, &pi->busy_work);
 
        return err;
@@ -3831,7 +3987,8 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
        int num_to_ack = (pi->tx_win/6) + 1;
        int err = 0;
 
-       BT_DBG("sk %p rx_control 0x%4.4x len %d", sk, rx_control, skb->len);
+       BT_DBG("sk %p len %d tx_seq %d rx_control 0x%4.4x", sk, skb->len, tx_seq,
+                                                               rx_control);
 
        if (L2CAP_CTRL_FINAL & rx_control &&
                        l2cap_pi(sk)->conn_state & L2CAP_CONN_WAIT_F) {
@@ -3853,7 +4010,7 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
 
        /* invalid tx_seq */
        if (tx_seq_offset >= pi->tx_win) {
-               l2cap_send_disconn_req(pi->conn, sk);
+               l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
                goto drop;
        }
 
@@ -3876,6 +4033,7 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
                                pi->buffer_seq = pi->buffer_seq_srej;
                                pi->conn_state &= ~L2CAP_CONN_SREJ_SENT;
                                l2cap_send_ack(pi);
+                               BT_DBG("sk %p, Exit SREJ_SENT", sk);
                        }
                } else {
                        struct srej_list *l;
@@ -3904,6 +4062,8 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
 
                pi->conn_state |= L2CAP_CONN_SREJ_SENT;
 
+               BT_DBG("sk %p, Enter SREJ", sk);
+
                INIT_LIST_HEAD(SREJ_LIST(sk));
                pi->buffer_seq_srej = pi->buffer_seq;
 
@@ -3914,6 +4074,8 @@ static inline int l2cap_data_channel_iframe(struct sock *sk, u16 rx_control, str
                pi->conn_state |= L2CAP_CONN_SEND_PBIT;
 
                l2cap_send_srejframe(sk, tx_seq);
+
+               del_timer(&pi->ack_timer);
        }
        return 0;
 
@@ -3927,6 +4089,10 @@ expected:
                return 0;
        }
 
+       err = l2cap_push_rx_skb(sk, skb, rx_control);
+       if (err < 0)
+               return 0;
+
        if (rx_control & L2CAP_CTRL_FINAL) {
                if (pi->conn_state & L2CAP_CONN_REJ_ACT)
                        pi->conn_state &= ~L2CAP_CONN_REJ_ACT;
@@ -3934,10 +4100,6 @@ expected:
                        l2cap_retransmit_frames(sk);
        }
 
-       err = l2cap_push_rx_skb(sk, skb, rx_control);
-       if (err < 0)
-               return 0;
-
        __mod_ack_timer();
 
        pi->num_acked = (pi->num_acked + 1) % num_to_ack;
@@ -3955,10 +4117,14 @@ static inline void l2cap_data_channel_rrframe(struct sock *sk, u16 rx_control)
 {
        struct l2cap_pinfo *pi = l2cap_pi(sk);
 
+       BT_DBG("sk %p, req_seq %d ctrl 0x%4.4x", sk, __get_reqseq(rx_control),
+                                               rx_control);
+
        pi->expected_ack_seq = __get_reqseq(rx_control);
        l2cap_drop_acked_frames(sk);
 
        if (rx_control & L2CAP_CTRL_POLL) {
+               pi->conn_state |= L2CAP_CONN_SEND_FBIT;
                if (pi->conn_state & L2CAP_CONN_SREJ_SENT) {
                        if ((pi->conn_state & L2CAP_CONN_REMOTE_BUSY) &&
                                        (pi->unacked_frames > 0))
@@ -3984,13 +4150,10 @@ static inline void l2cap_data_channel_rrframe(struct sock *sk, u16 rx_control)
                        __mod_retrans_timer();
 
                pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
-               if (pi->conn_state & L2CAP_CONN_SREJ_SENT) {
+               if (pi->conn_state & L2CAP_CONN_SREJ_SENT)
                        l2cap_send_ack(pi);
-               } else {
-                       spin_lock_bh(&pi->send_lock);
+               else
                        l2cap_ertm_send(sk);
-                       spin_unlock_bh(&pi->send_lock);
-               }
        }
 }
 
@@ -3999,6 +4162,8 @@ static inline void l2cap_data_channel_rejframe(struct sock *sk, u16 rx_control)
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        u8 tx_seq = __get_reqseq(rx_control);
 
+       BT_DBG("sk %p, req_seq %d ctrl 0x%4.4x", sk, tx_seq, rx_control);
+
        pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
 
        pi->expected_ack_seq = tx_seq;
@@ -4021,16 +4186,18 @@ static inline void l2cap_data_channel_srejframe(struct sock *sk, u16 rx_control)
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        u8 tx_seq = __get_reqseq(rx_control);
 
+       BT_DBG("sk %p, req_seq %d ctrl 0x%4.4x", sk, tx_seq, rx_control);
+
        pi->conn_state &= ~L2CAP_CONN_REMOTE_BUSY;
 
        if (rx_control & L2CAP_CTRL_POLL) {
                pi->expected_ack_seq = tx_seq;
                l2cap_drop_acked_frames(sk);
+
+               pi->conn_state |= L2CAP_CONN_SEND_FBIT;
                l2cap_retransmit_one_frame(sk, tx_seq);
 
-               spin_lock_bh(&pi->send_lock);
                l2cap_ertm_send(sk);
-               spin_unlock_bh(&pi->send_lock);
 
                if (pi->conn_state & L2CAP_CONN_WAIT_F) {
                        pi->srej_save_reqseq = tx_seq;
@@ -4056,10 +4223,15 @@ static inline void l2cap_data_channel_rnrframe(struct sock *sk, u16 rx_control)
        struct l2cap_pinfo *pi = l2cap_pi(sk);
        u8 tx_seq = __get_reqseq(rx_control);
 
+       BT_DBG("sk %p, req_seq %d ctrl 0x%4.4x", sk, tx_seq, rx_control);
+
        pi->conn_state |= L2CAP_CONN_REMOTE_BUSY;
        pi->expected_ack_seq = tx_seq;
        l2cap_drop_acked_frames(sk);
 
+       if (rx_control & L2CAP_CTRL_POLL)
+               pi->conn_state |= L2CAP_CONN_SEND_FBIT;
+
        if (!(pi->conn_state & L2CAP_CONN_SREJ_SENT)) {
                del_timer(&pi->retrans_timer);
                if (rx_control & L2CAP_CTRL_POLL)
@@ -4107,13 +4279,83 @@ static inline int l2cap_data_channel_sframe(struct sock *sk, u16 rx_control, str
        return 0;
 }
 
+static int l2cap_ertm_data_rcv(struct sock *sk, struct sk_buff *skb)
+{
+       struct l2cap_pinfo *pi = l2cap_pi(sk);
+       u16 control;
+       u8 req_seq;
+       int len, next_tx_seq_offset, req_seq_offset;
+
+       control = get_unaligned_le16(skb->data);
+       skb_pull(skb, 2);
+       len = skb->len;
+
+       /*
+        * We can just drop the corrupted I-frame here.
+        * Receiver will miss it and start proper recovery
+        * procedures and ask retransmission.
+        */
+       if (l2cap_check_fcs(pi, skb))
+               goto drop;
+
+       if (__is_sar_start(control) && __is_iframe(control))
+               len -= 2;
+
+       if (pi->fcs == L2CAP_FCS_CRC16)
+               len -= 2;
+
+       if (len > pi->mps) {
+               l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
+               goto drop;
+       }
+
+       req_seq = __get_reqseq(control);
+       req_seq_offset = (req_seq - pi->expected_ack_seq) % 64;
+       if (req_seq_offset < 0)
+               req_seq_offset += 64;
+
+       next_tx_seq_offset =
+               (pi->next_tx_seq - pi->expected_ack_seq) % 64;
+       if (next_tx_seq_offset < 0)
+               next_tx_seq_offset += 64;
+
+       /* check for invalid req-seq */
+       if (req_seq_offset > next_tx_seq_offset) {
+               l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
+               goto drop;
+       }
+
+       if (__is_iframe(control)) {
+               if (len < 0) {
+                       l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
+                       goto drop;
+               }
+
+               l2cap_data_channel_iframe(sk, control, skb);
+       } else {
+               if (len != 0) {
+                       BT_ERR("%d", len);
+                       l2cap_send_disconn_req(pi->conn, sk, ECONNRESET);
+                       goto drop;
+               }
+
+               l2cap_data_channel_sframe(sk, control, skb);
+       }
+
+       return 0;
+
+drop:
+       kfree_skb(skb);
+       return 0;
+}
+
 static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk_buff *skb)
 {
        struct sock *sk;
        struct l2cap_pinfo *pi;
        u16 control;
-       u8 tx_seq, req_seq;
-       int len, next_tx_seq_offset, req_seq_offset;
+       u8 tx_seq;
+       int len;
 
        sk = l2cap_get_chan_by_scid(&conn->chan_list, cid);
        if (!sk) {
@@ -4143,59 +4385,11 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
                break;
 
        case L2CAP_MODE_ERTM:
-               control = get_unaligned_le16(skb->data);
-               skb_pull(skb, 2);
-               len = skb->len;
-
-               if (__is_sar_start(control) && __is_iframe(control))
-                       len -= 2;
-
-               if (pi->fcs == L2CAP_FCS_CRC16)
-                       len -= 2;
-
-               /*
-                * We can just drop the corrupted I-frame here.
-                * Receiver will miss it and start proper recovery
-                * procedures and ask retransmission.
-                */
-               if (len > pi->mps) {
-                       l2cap_send_disconn_req(pi->conn, sk);
-                       goto drop;
-               }
-
-               if (l2cap_check_fcs(pi, skb))
-                       goto drop;
-
-               req_seq = __get_reqseq(control);
-               req_seq_offset = (req_seq - pi->expected_ack_seq) % 64;
-               if (req_seq_offset < 0)
-                       req_seq_offset += 64;
-
-               next_tx_seq_offset =
-                       (pi->next_tx_seq - pi->expected_ack_seq) % 64;
-               if (next_tx_seq_offset < 0)
-                       next_tx_seq_offset += 64;
-
-               /* check for invalid req-seq */
-               if (req_seq_offset > next_tx_seq_offset) {
-                       l2cap_send_disconn_req(pi->conn, sk);
-                       goto drop;
-               }
-
-               if (__is_iframe(control)) {
-                       if (len < 0) {
-                               l2cap_send_disconn_req(pi->conn, sk);
-                               goto drop;
-                       }
-
-                       l2cap_data_channel_iframe(sk, control, skb);
+               if (!sock_owned_by_user(sk)) {
+                       l2cap_ertm_data_rcv(sk, skb);
                } else {
-                       if (len != 0) {
-                               l2cap_send_disconn_req(pi->conn, sk);
+                       if (sk_add_backlog(sk, skb))
                                goto drop;
-                       }
-
-                       l2cap_data_channel_sframe(sk, control, skb);
                }
 
                goto done;
@@ -4205,6 +4399,9 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
                skb_pull(skb, 2);
                len = skb->len;
 
+               if (l2cap_check_fcs(pi, skb))
+                       goto drop;
+
                if (__is_sar_start(control))
                        len -= 2;
 
@@ -4214,9 +4411,6 @@ static inline int l2cap_data_channel(struct l2cap_conn *conn, u16 cid, struct sk
                if (len > pi->mps || len < 0 || __is_sframe(control))
                        goto drop;
 
-               if (l2cap_check_fcs(pi, skb))
-                       goto drop;
-
                tx_seq = __get_txseq(control);
 
                if (pi->expected_tx_seq == tx_seq)
@@ -4251,6 +4445,8 @@ static inline int l2cap_conless_channel(struct l2cap_conn *conn, __le16 psm, str
        if (!sk)
                goto drop;
 
+       bh_lock_sock(sk);
+
        BT_DBG("sk %p, len %d", sk, skb->len);
 
        if (sk->sk_state != BT_BOUND && sk->sk_state != BT_CONNECTED)
@@ -4314,7 +4510,7 @@ static int l2cap_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, u8 type)
        struct hlist_node *node;
 
        if (type != ACL_LINK)
-               return 0;
+               return -EINVAL;
 
        BT_DBG("hdev %s, bdaddr %s", hdev->name, batostr(bdaddr));
 
@@ -4347,7 +4543,7 @@ static int l2cap_connect_cfm(struct hci_conn *hcon, u8 status)
        BT_DBG("hcon %p bdaddr %s status %d", hcon, batostr(&hcon->dst), status);
 
        if (hcon->type != ACL_LINK)
-               return 0;
+               return -EINVAL;
 
        if (!status) {
                conn = l2cap_conn_add(hcon, status);
@@ -4376,7 +4572,7 @@ static int l2cap_disconn_cfm(struct hci_conn *hcon, u8 reason)
        BT_DBG("hcon %p reason %d", hcon, reason);
 
        if (hcon->type != ACL_LINK)
-               return 0;
+               return -EINVAL;
 
        l2cap_conn_del(hcon, bt_err(reason));
 
@@ -4485,6 +4681,8 @@ static int l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 fl
 
        if (flags & ACL_START) {
                struct l2cap_hdr *hdr;
+               struct sock *sk;
+               u16 cid;
                int len;
 
                if (conn->rx_len) {
@@ -4495,7 +4693,8 @@ static int l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 fl
                        l2cap_conn_unreliable(conn, ECOMM);
                }
 
-               if (skb->len < 2) {
+               /* Start fragment always begin with Basic L2CAP header */
+               if (skb->len < L2CAP_HDR_SIZE) {
                        BT_ERR("Frame is too short (len %d)", skb->len);
                        l2cap_conn_unreliable(conn, ECOMM);
                        goto drop;
@@ -4503,6 +4702,7 @@ static int l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 fl
 
                hdr = (struct l2cap_hdr *) skb->data;
                len = __le16_to_cpu(hdr->len) + L2CAP_HDR_SIZE;
+               cid = __le16_to_cpu(hdr->cid);
 
                if (len == skb->len) {
                        /* Complete frame received */
@@ -4519,6 +4719,19 @@ static int l2cap_recv_acldata(struct hci_conn *hcon, struct sk_buff *skb, u16 fl
                        goto drop;
                }
 
+               sk = l2cap_get_chan_by_scid(&conn->chan_list, cid);
+
+               if (sk && l2cap_pi(sk)->imtu < len - L2CAP_HDR_SIZE) {
+                       BT_ERR("Frame exceeding recv MTU (len %d, MTU %d)",
+                                       len, l2cap_pi(sk)->imtu);
+                       bh_unlock_sock(sk);
+                       l2cap_conn_unreliable(conn, ECOMM);
+                       goto drop;
+               }
+
+               if (sk)
+                       bh_unlock_sock(sk);
+
                /* Allocate skb for the complete frame (with header) */
                conn->rx_skb = bt_skb_alloc(len, GFP_ATOMIC);
                if (!conn->rx_skb)
@@ -4645,8 +4858,10 @@ static int __init l2cap_init(void)
                return err;
 
        _busy_wq = create_singlethread_workqueue("l2cap");
-       if (!_busy_wq)
-               goto error;
+       if (!_busy_wq) {
+               proto_unregister(&l2cap_proto);
+               return -ENOMEM;
+       }
 
        err = bt_sock_register(BTPROTO_L2CAP, &l2cap_sock_family_ops);
        if (err < 0) {
@@ -4674,6 +4889,7 @@ static int __init l2cap_init(void)
        return 0;
 
 error:
+       destroy_workqueue(_busy_wq);
        proto_unregister(&l2cap_proto);
        return err;
 }
@@ -4705,8 +4921,8 @@ EXPORT_SYMBOL(l2cap_load);
 module_init(l2cap_init);
 module_exit(l2cap_exit);
 
-module_param(enable_ertm, bool, 0644);
-MODULE_PARM_DESC(enable_ertm, "Enable enhanced retransmission mode");
+module_param(disable_ertm, bool, 0644);
+MODULE_PARM_DESC(disable_ertm, "Disable enhanced retransmission mode");
 
 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
 MODULE_DESCRIPTION("Bluetooth L2CAP ver " VERSION);