diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
index 6e6e2b19815c..2819e001797b 100644
--- a/drivers/bluetooth/btintel_pcie.c
+++ b/drivers/bluetooth/btintel_pcie.c
@@ -1099,6 +1099,11 @@ static void btintel_pcie_msix_tx_handle(struct btintel_pcie_data *data)
 
 	txq = &data->txq;
 
+	if (cr_hia >= txq->count) {
+		bt_dev_err(data->hdev, "TXQ: invalid cr_hia %u", cr_hia);
+		return;
+	}
+
 	while (cr_tia != cr_hia) {
 		data->tx_wait_done = true;
 		wake_up(&data->tx_wait_q);
@@ -1650,6 +1655,11 @@ static void btintel_pcie_msix_rx_handle(struct btintel_pcie_data *data)
 
 	rxq = &data->rxq;
 
+	if (cr_hia >= rxq->count) {
+		bt_dev_err(hdev, "RXQ: invalid cr_hia %u", cr_hia);
+		return;
+	}
+
 	/* The firmware sends multiple CD in a single MSI-X and it needs to
 	 * process all received CDs in this interrupt.
 	 */
@@ -1657,6 +1667,12 @@ static void btintel_pcie_msix_rx_handle(struct btintel_pcie_data *data)
 		urbd1 = &rxq->urbd1s[cr_tia];
 		ipc_print_urbd1(data->hdev, urbd1, cr_tia);
 
+		if (urbd1->frbd_tag >= rxq->count) {
+			bt_dev_err(hdev, "RXQ: invalid frbd_tag %u",
+				   urbd1->frbd_tag);
+			return;
+		}
+
 		buf = &rxq->bufs[urbd1->frbd_tag];
 		if (!buf) {
 			bt_dev_err(hdev, "RXQ: failed to get the DMA buffer for %d",
diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
index 25e7b41b349f..4e23d71d00e8 100644
--- a/drivers/bluetooth/btnxpuart.c
+++ b/drivers/bluetooth/btnxpuart.c
@@ -1388,9 +1388,11 @@ static int nxp_process_fw_dump(struct hci_dev *hdev, struct sk_buff *skb)
 				      msecs_to_jiffies(20000));
 	}
 
-	err = hci_devcd_append(hdev, skb_clone(skb, GFP_ATOMIC));
-	if (err < 0)
-		goto free_skb;
+	if (IS_ENABLED(CONFIG_DEV_COREDUMP)) {
+		err = hci_devcd_append(hdev, skb_clone(skb, GFP_ATOMIC));
+		if (err < 0)
+			goto free_skb;
+	}
 
 	if (buf_len == 0) {
 		bt_dev_warn(hdev, "==== FW dump complete ===");
diff --git a/net/bluetooth/bnep/core.c b/net/bluetooth/bnep/core.c
index f7d88c33e23e..ad24d2486665 100644
--- a/net/bluetooth/bnep/core.c
+++ b/net/bluetooth/bnep/core.c
@@ -270,9 +270,14 @@ static int bnep_rx_extension(struct bnep_session *s, struct sk_buff *skb)
 
 		BT_DBG("type 0x%x len %u", h->type, h->len);
 
+		if (skb->len < h->len) {
+			err = -EILSEQ;
+			break;
+		}
+
 		switch (h->type & BNEP_TYPE_MASK) {
 		case BNEP_EXT_CONTROL:
-			bnep_rx_control(s, skb->data, skb->len);
+			bnep_rx_control(s, skb->data, h->len);
 			break;
 
 		default:
@@ -373,6 +378,11 @@ static int bnep_rx_frame(struct bnep_session *s, struct sk_buff *skb)
 			goto badframe;
 	}
 
+	if ((type & BNEP_TYPE_MASK) == BNEP_CONTROL) {
+		kfree_skb(skb);
+		return 0;
+	}
+
 	/* Strip 802.1p header */
 	if (ntohs(s->eh.h_proto) == ETH_P_8021Q) {
 		if (!skb_pull(skb, 4))
@@ -451,6 +461,11 @@ static int bnep_tx_frame(struct bnep_session *s, struct sk_buff *skb)
 		goto send;
 	}
 
+	if (skb->len < ETH_HLEN) {
+		kfree_skb(skb);
+		return 0;
+	}
+
 	iv[il++] = (struct kvec) { &type, 1 };
 	len++;
 
diff --git a/net/bluetooth/bnep/netdev.c b/net/bluetooth/bnep/netdev.c
index ee1e39a3daff..b451ef457741 100644
--- a/net/bluetooth/bnep/netdev.c
+++ b/net/bluetooth/bnep/netdev.c
@@ -166,6 +166,12 @@ static netdev_tx_t bnep_net_xmit(struct sk_buff *skb,
 
 	BT_DBG("skb %p, dev %p", skb, dev);
 
+	if (!pskb_may_pull(skb, ETH_HLEN)) {
+		dev->stats.tx_dropped++;
+		kfree_skb(skb);
+		return NETDEV_TX_OK;
+	}
+
 #ifdef CONFIG_BT_BNEP_MC_FILTER
 	if (bnep_net_mc_filter(skb, s)) {
 		kfree_skb(skb);
@@ -218,7 +224,7 @@ void bnep_net_setup(struct net_device *dev)
 	dev->addr_len = ETH_ALEN;
 
 	ether_setup(dev);
-	dev->min_mtu = 0;
+	dev->min_mtu = ETH_MIN_MTU;
 	dev->max_mtu = ETH_MAX_MTU;
 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 	dev->netdev_ops = &bnep_netdev_ops;
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index fa72cf8aaa7a..96195d2fd10f 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -2079,6 +2079,8 @@ struct hci_conn *hci_bind_cis(struct hci_dev *hdev, bdaddr_t *dst,
 		cis->conn_timeout = timeout;
 	}
 
+	hci_conn_hold(cis);
+
 	if (cis->state == BT_CONNECTED)
 		return cis;
 
@@ -2120,7 +2122,6 @@ struct hci_conn *hci_bind_cis(struct hci_dev *hdev, bdaddr_t *dst,
 		return ERR_PTR(-EINVAL);
 	}
 
-	hci_conn_hold(cis);
 	cis->state = BT_BOUND;
 
 	return cis;
@@ -2374,10 +2375,13 @@ struct hci_conn *hci_bind_bis(struct hci_dev *hdev, bdaddr_t *dst, __u8 sid,
 	parent = hci_conn_hash_lookup_big(hdev,
 					  conn->iso_qos.bcast.big);
 	if (parent && parent != conn) {
+		hci_conn_hold(parent);
 		link = hci_conn_link(parent, conn);
 		hci_conn_drop(conn);
-		if (!link)
+		if (!link) {
+			hci_conn_drop(parent);
 			return ERR_PTR(-ENOLINK);
+		}
 	}
 
 	return conn;
@@ -2497,6 +2501,12 @@ struct hci_conn *hci_connect_cis(struct hci_dev *hdev, bdaddr_t *dst,
 		return cis;
 	}
 
+	/* The existing link already owns the hold on its parent. */
+	if (cis->link) {
+		hci_conn_drop(le);
+		return cis;
+	}
+
 	link = hci_conn_link(le, cis);
 	hci_conn_drop(cis);
 	if (!link) {
diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 070ca388f9ac..6d56c77741e1 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -164,6 +164,7 @@ static bool is_filtered_packet(struct sock *sk, struct sk_buff *skb)
 {
 	struct hci_filter *flt;
 	int flt_type, flt_event;
+	u8 event;
 
 	/* Apply filter */
 	flt = &hci_pi(sk)->filter;
@@ -177,7 +178,11 @@ static bool is_filtered_packet(struct sock *sk, struct sk_buff *skb)
 	if (hci_skb_pkt_type(skb) != HCI_EVENT_PKT)
 		return false;
 
-	flt_event = (*(__u8 *)skb->data & HCI_FLT_EVENT_BITS);
+	if (skb->len < 1)
+		return true;
+
+	event = *(__u8 *)skb->data;
+	flt_event = event & HCI_FLT_EVENT_BITS;
 
 	if (!hci_test_bit(flt_event, &flt->event_mask))
 		return true;
@@ -186,11 +191,17 @@ static bool is_filtered_packet(struct sock *sk, struct sk_buff *skb)
 	if (!flt->opcode)
 		return false;
 
-	if (flt_event == HCI_EV_CMD_COMPLETE &&
+	if (event == HCI_EV_CMD_COMPLETE && skb->len < 5)
+		return true;
+
+	if (event == HCI_EV_CMD_COMPLETE &&
 	    flt->opcode != get_unaligned((__le16 *)(skb->data + 3)))
 		return true;
 
-	if (flt_event == HCI_EV_CMD_STATUS &&
+	if (event == HCI_EV_CMD_STATUS && skb->len < 6)
+		return true;
+
+	if (event == HCI_EV_CMD_STATUS &&
 	    flt->opcode != get_unaligned((__le16 *)(skb->data + 4)))
 		return true;
 
@@ -1881,7 +1892,8 @@ static int hci_sock_sendmsg(struct socket *sock, struct msghdr *msg,
 		u16 ocf = hci_opcode_ocf(opcode);
 
 		if (((ogf > HCI_SFLT_MAX_OGF) ||
-		     !hci_test_bit(ocf & HCI_FLT_OCF_BITS,
+		     (ocf > HCI_FLT_OCF_BITS) ||
+		     !hci_test_bit(ocf,
 				   &hci_sec_filter.ocf_mask[ogf])) &&
 		    !capable(CAP_NET_RAW)) {
 			err = -EPERM;
diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index eb99653f33f9..7657c2a0abbf 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -496,6 +496,7 @@ static int iso_connect_cis(struct sock *sk)
 	struct hci_dev  *hdev;
 	bdaddr_t src, dst;
 	u8 src_type;
+	bool already_attached;
 	int err;
 
 	lock_sock(sk);
@@ -568,8 +569,14 @@ static int iso_connect_cis(struct sock *sk)
 		goto unlock;
 	}
 
+	iso_conn_lock(conn);
+	already_attached = iso_pi(sk)->conn == conn && conn->sk == sk;
+	iso_conn_unlock(conn);
+
 	err = iso_chan_add(conn, sk, NULL);
 	iso_conn_put(conn);
+	if (already_attached || err == -EBUSY)
+		hci_conn_drop(hcon);
 	if (err)
 		goto unlock;
 
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 644e31160d55..aaa2a1cd489a 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -6702,9 +6702,17 @@ static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
 static int l2cap_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
 {
 	struct l2cap_ctrl *control = &bt_cb(skb)->l2cap;
-	u16 len;
+	u16 len, min_len;
 	u8 event;
 
+	min_len = test_bit(FLAG_EXT_CTRL, &chan->flags) ?
+		  L2CAP_EXT_CTRL_SIZE : L2CAP_ENH_CTRL_SIZE;
+	if (chan->fcs == L2CAP_FCS_CRC16)
+		min_len += L2CAP_FCS_SIZE;
+
+	if (skb->len < min_len)
+		goto drop;
+
 	__unpack_control(chan, skb);
 
 	len = skb->len;
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index ac4864e56ec7..41956cdde982 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -496,13 +496,9 @@ static int read_unconf_index_list(struct sock *sk, struct hci_dev *hdev,
 
 	read_lock(&hci_dev_list_lock);
 
-	count = 0;
-	list_for_each_entry(d, &hci_dev_list, list) {
-		if (hci_dev_test_flag(d, HCI_UNCONFIGURED))
-			count++;
-	}
+	count = list_count_nodes(&hci_dev_list);
 
-	rp_len = sizeof(*rp) + (2 * count);
+	rp_len = sizeof(*rp) + (sizeof(__le16) * count);
 	rp = kmalloc(rp_len, GFP_ATOMIC);
 	if (!rp) {
 		read_unlock(&hci_dev_list_lock);
@@ -2316,6 +2312,8 @@ static void mesh_send_start_complete(struct hci_dev *hdev, void *data, int err)
 		hci_dev_clear_flag(hdev, HCI_MESH_SENDING);
 		/* Send Complete Error Code for handle */
 		mesh_send_complete(hdev, mesh_tx, false);
+		if (err != -ECANCELED)
+			mesh_next(hdev, NULL, 0);
 		return;
 	}
 
@@ -2425,19 +2423,28 @@ static int send_cancel(struct hci_dev *hdev, void *data)
 		do {
 			mesh_tx = mgmt_mesh_next(hdev, cmd->sk);
 
-			if (mesh_tx)
-				mesh_send_complete(hdev, mesh_tx, false);
+			if (mesh_tx) {
+				if (!hci_cmd_sync_dequeue(hdev, mesh_send_sync,
+							  mesh_tx, NULL))
+					mesh_send_complete(hdev, mesh_tx, false);
+			}
 		} while (mesh_tx);
 	} else {
 		mesh_tx = mgmt_mesh_find(hdev, cancel->handle);
 
-		if (mesh_tx && mesh_tx->sk == cmd->sk)
-			mesh_send_complete(hdev, mesh_tx, false);
+		if (mesh_tx && mesh_tx->sk == cmd->sk) {
+			if (!hci_cmd_sync_dequeue(hdev, mesh_send_sync,
+						  mesh_tx, NULL))
+				mesh_send_complete(hdev, mesh_tx, false);
+		}
 	}
 
 	mgmt_cmd_complete(cmd->sk, hdev->id, MGMT_OP_MESH_SEND_CANCEL,
 			  0, NULL, 0);
 
+	if (!hci_dev_test_flag(hdev, HCI_MESH_SENDING))
+		mesh_next(hdev, NULL, 0);
+
 	return 0;
 }
 
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index f7463f092283..d91e2a6ee26c 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -1817,7 +1817,8 @@ static struct rfcomm_session *rfcomm_recv_frame(struct rfcomm_session *s,
 		return s;
 	}
 
-	if (skb->len < sizeof(*hdr) + 1) {
+	if (skb->len < sizeof(*hdr) + 1 ||
+	    (!__test_ea(hdr->len) && skb->len < sizeof(*hdr) + 2)) {
 		kfree_skb(skb);
 		return s;
 	}
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index e2486bc11cbc..fb924d0e34ec 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -786,8 +786,10 @@ static int rfcomm_sock_getsockopt_old(struct socket *sock, int optname,
 		break;
 
 	case RFCOMM_CONNINFO:
-		if (sk->sk_state != BT_CONNECTED &&
-					!rfcomm_pi(sk)->dlc->defer_setup) {
+		if ((sk->sk_state != BT_CONNECTED &&
+		     !(sk->sk_state == BT_CONNECT2 &&
+		       rfcomm_pi(sk)->dlc->defer_setup)) ||
+		    !rfcomm_pi(sk)->dlc->session) {
 			err = -ENOTCONN;
 			break;
 		}
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
index 6091c47cb002..d23f9d0729c4 100644
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -2269,6 +2269,23 @@ static u8 smp_cmd_security_req(struct l2cap_conn *conn, struct sk_buff *skb)
 
 	bt_dev_dbg(hdev, "conn %p", conn);
 
+	/* SMP over BR/EDR only covers cross-transport key derivation; the
+	 * Security Request procedure has no BR/EDR counterpart. Reject it
+	 * here, otherwise smp_ltk_encrypt() finds the peer's LE LTK
+	 * (ADDR_LE_DEV_PUBLIC and BDADDR_BREDR are both 0) and issues
+	 * HCI_OP_LE_START_ENC on the ACL handle, which the controller
+	 * rejects and hci_cs_le_start_enc() turns into a disconnect. Reply
+	 * without smp_failure(): this is not an authentication failure, and
+	 * MGMT_EV_AUTH_FAILED would make bluetoothd drop the device.
+	 */
+	if (hcon->type != LE_LINK) {
+		u8 reason = SMP_CMD_NOTSUPP;
+
+		smp_send_cmd(conn, SMP_CMD_PAIRING_FAIL, sizeof(reason),
+			     &reason);
+		return 0;
+	}
+
 	if (skb->len < sizeof(*rp))
 		return SMP_INVALID_PARAMS;