diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c
--- a/drivers/bluetooth/btintel.c
+++ b/drivers/bluetooth/btintel.c
@@ -288,7 +288,8 @@ void btintel_hw_error(struct hci_dev *hdev, u8 code)
 		goto unlock;
 	}
 
-	bt_dev_err(hdev, "Exception info %s", (char *)(skb->data + 1));
+	bt_dev_err(hdev, "Exception info %.*s", (int)(skb->len - 1),
+		   (char *)(skb->data + 1));
 
 	kfree_skb(skb);
 
@@ -407,8 +408,16 @@ int btintel_load_ddc_config(struct hci_dev *hdev, const char *ddc_name)
 	/* DDC file contains one or more DDC structure which has
 	 * Length (1 byte), DDC ID (2 bytes), and DDC value (Length - 2).
 	 */
-	while (fw->size > fw_ptr - fw->data) {
-		u8 cmd_plen = fw_ptr[0] + sizeof(u8);
+	while (fw->size > (size_t)(fw_ptr - fw->data)) {
+		size_t remaining = fw->size - (fw_ptr - fw->data);
+		unsigned int cmd_plen = fw_ptr[0] + 1U;
+
+		if (cmd_plen < 3 || cmd_plen > U8_MAX || cmd_plen > remaining) {
+			bt_dev_err(hdev, "Malformed DDC record (plen=%u, remaining=%zu)",
+				   cmd_plen, remaining);
+			release_firmware(fw);
+			return -EINVAL;
+		}
 
 		skb = __hci_cmd_sync(hdev, 0xfc8b, cmd_plen, fw_ptr,
 				     HCI_INIT_TIMEOUT);
diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c
--- a/drivers/bluetooth/btintel_pcie.c
+++ b/drivers/bluetooth/btintel_pcie.c
@@ -1200,7 +1200,7 @@ static int btintel_pcie_recv_frame(struct btintel_pcie_data *data,
 {
 	int ret;
 	u8 pkt_type;
-	u16 plen;
+	u32 plen;
 	u32 pcie_pkt_type;
 	void *pdata;
 	struct hci_dev *hdev = data->hdev;
@@ -2149,6 +2149,16 @@ static int btintel_pcie_send_frame(struct hci_dev *hdev,
 	if (test_bit(BTINTEL_PCIE_RECOVERY_IN_PROGRESS, &data->flags))
 		return -ENODEV;
 
+	/* Account for the 4-byte PCIe type header prepended before the
+	 * DMA copy.  Written as a subtraction to avoid wrap-around on
+	 * attacker-controlled skb->len.
+	 */
+	if (skb->len > BTINTEL_PCIE_BUFFER_SIZE - BTINTEL_PCIE_HCI_TYPE_LEN) {
+		bt_dev_err(hdev, "Packet too large: %u > %u", skb->len,
+			   BTINTEL_PCIE_BUFFER_SIZE - BTINTEL_PCIE_HCI_TYPE_LEN);
+		return -EMSGSIZE;
+	}
+
 	/* Due to the fw limitation, the type header of the packet should be
 	 * 4 bytes unlike 1 byte for UART. In UART, the firmware can read
 	 * the first byte to get the packet type and redirect the rest of data
diff --git a/include/net/bluetooth/hci_core.h b/include/net/bluetooth/hci_core.h
--- a/include/net/bluetooth/hci_core.h
+++ b/include/net/bluetooth/hci_core.h
@@ -62,7 +62,7 @@ struct inquiry_entry {
 		NAME_PENDING,
 		NAME_KNOWN,
 	} name_state;
-	__u32			timestamp;
+	unsigned long		timestamp;
 	struct inquiry_data	data;
 };
 
@@ -78,7 +78,7 @@ struct discovery_state {
 	struct list_head	all;	/* All devices found during inquiry */
 	struct list_head	unknown;	/* Name state not known */
 	struct list_head	resolve;	/* Name needs to be resolved */
-	__u32			timestamp;
+	unsigned long		timestamp;
 	bdaddr_t		last_adv_addr;
 	u8			last_adv_addr_type;
 	s8			last_adv_rssi;
@@ -561,6 +561,7 @@ struct hci_dev {
 	struct list_head	link_keys;
 	struct list_head	long_term_keys;
 	struct list_head	identity_resolving_keys;
+	struct mutex		remote_oob_lock;
 	struct list_head	remote_oob_data;
 	struct list_head	le_accept_list;
 	struct list_head	le_resolv_list;
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -302,11 +302,13 @@ static int hci_enhanced_setup_sync(struct hci_dev *hdev, void *data)
 	cp.tx_bandwidth   = cpu_to_le32(0x00001f40);
 	cp.rx_bandwidth   = cpu_to_le32(0x00001f40);
 
+	hci_dev_lock(hdev);
+
 	switch (conn->codec.id) {
 	case BT_CODEC_MSBC:
 		if (!find_next_esco_param(conn, esco_param_msbc,
 					  ARRAY_SIZE(esco_param_msbc)))
-			return -EINVAL;
+			goto unlock;
 
 		param = &esco_param_msbc[conn->attempt - 1];
 		cp.tx_coding_format.id = 0x05;
@@ -332,7 +334,7 @@ static int hci_enhanced_setup_sync(struct hci_dev *hdev, void *data)
 	case BT_CODEC_TRANSPARENT:
 		if (!find_next_esco_param(conn, esco_param_msbc,
 					  ARRAY_SIZE(esco_param_msbc)))
-			return -EINVAL;
+			goto unlock;
 
 		param = &esco_param_msbc[conn->attempt - 1];
 		cp.tx_coding_format.id = 0x03;
@@ -359,11 +361,11 @@ static int hci_enhanced_setup_sync(struct hci_dev *hdev, void *data)
 		if (conn->parent && lmp_esco_capable(conn->parent)) {
 			if (!find_next_esco_param(conn, esco_param_cvsd,
 						  ARRAY_SIZE(esco_param_cvsd)))
-				return -EINVAL;
+				goto unlock;
 			param = &esco_param_cvsd[conn->attempt - 1];
 		} else {
 			if (conn->attempt > ARRAY_SIZE(sco_param_cvsd))
-				return -EINVAL;
+				goto unlock;
 			param = &sco_param_cvsd[conn->attempt - 1];
 		}
 		cp.tx_coding_format.id = 2;
@@ -386,9 +388,11 @@ static int hci_enhanced_setup_sync(struct hci_dev *hdev, void *data)
 		cp.out_transport_unit_size = 16;
 		break;
 	default:
-		return -EINVAL;
+		goto unlock;
 	}
 
+	hci_dev_unlock(hdev);
+
 	cp.retrans_effort = param->retrans_effort;
 	cp.pkt_type = __cpu_to_le16(param->pkt_type);
 	cp.max_latency = __cpu_to_le16(param->max_latency);
@@ -397,6 +401,10 @@ static int hci_enhanced_setup_sync(struct hci_dev *hdev, void *data)
 		return -EIO;
 
 	return 0;
+
+unlock:
+	hci_dev_unlock(hdev);
+	return -EINVAL;
 }
 
 static bool hci_setup_sync_conn(struct hci_conn *conn, __u16 handle)
diff --git a/net/bluetooth/hci_core.c b/net/bluetooth/hci_core.c
--- a/net/bluetooth/hci_core.c
+++ b/net/bluetooth/hci_core.c
@@ -1486,8 +1486,10 @@ int hci_remove_remote_oob_data(struct hci_dev *hdev, bdaddr_t *bdaddr,
 
 	BT_DBG("%s removing %pMR (%u)", hdev->name, bdaddr, bdaddr_type);
 
+	mutex_lock(&hdev->remote_oob_lock);
 	list_del(&data->list);
 	kfree(data);
+	mutex_unlock(&hdev->remote_oob_lock);
 
 	return 0;
 }
@@ -1496,10 +1498,12 @@ void hci_remote_oob_data_clear(struct hci_dev *hdev)
 {
 	struct oob_data *data, *n;
 
+	mutex_lock(&hdev->remote_oob_lock);
 	list_for_each_entry_safe(data, n, &hdev->remote_oob_data, list) {
 		list_del(&data->list);
 		kfree(data);
 	}
+	mutex_unlock(&hdev->remote_oob_lock);
 }
 
 int hci_add_remote_oob_data(struct hci_dev *hdev, bdaddr_t *bdaddr,
@@ -1508,11 +1512,14 @@ int hci_add_remote_oob_data(struct hci_dev *hdev, bdaddr_t *bdaddr,
 {
 	struct oob_data *data;
 
+	mutex_lock(&hdev->remote_oob_lock);
 	data = hci_find_remote_oob_data(hdev, bdaddr, bdaddr_type);
 	if (!data) {
 		data = kmalloc_obj(*data);
-		if (!data)
+		if (!data) {
+			mutex_unlock(&hdev->remote_oob_lock);
 			return -ENOMEM;
+		}
 
 		bacpy(&data->bdaddr, bdaddr);
 		data->bdaddr_type = bdaddr_type;
@@ -1545,6 +1552,8 @@ int hci_add_remote_oob_data(struct hci_dev *hdev, bdaddr_t *bdaddr,
 
 	BT_DBG("%s for %pMR", hdev->name, bdaddr);
 
+	mutex_unlock(&hdev->remote_oob_lock);
+
 	return 0;
 }
 
@@ -2482,6 +2491,7 @@ struct hci_dev *hci_alloc_dev_priv(int sizeof_priv)
 	mutex_init(&hdev->lock);
 	mutex_init(&hdev->req_lock);
 	mutex_init(&hdev->mgmt_pending_lock);
+	mutex_init(&hdev->remote_oob_lock);
 
 	ida_init(&hdev->unset_handle_ida);
 
@@ -2554,8 +2564,10 @@ int hci_register_dev(struct hci_dev *hdev)
 		return id;
 
 	error = dev_set_name(&hdev->dev, "hci%u", id);
-	if (error)
+	if (error) {
+		ida_free(&hci_index_ida, id);
 		return error;
+	}
 
 	hdev->name = dev_name(&hdev->dev);
 	hdev->id = id;
@@ -3323,6 +3335,8 @@ static void hci_queue_iso(struct hci_conn *conn, struct sk_buff_head *queue,
 
 		skb_shinfo(skb)->frag_list = NULL;
 
+		spin_lock_bh(&queue->lock);
+
 		__skb_queue_tail(queue, skb);
 
 		do {
@@ -3337,6 +3351,8 @@ static void hci_queue_iso(struct hci_conn *conn, struct sk_buff_head *queue,
 
 			__skb_queue_tail(queue, skb);
 		} while (list);
+
+		spin_unlock_bh(&queue->lock);
 	}
 
 	bt_dev_dbg(hdev, "hcon %p queued %d", conn, skb_queue_len(queue));
@@ -3400,9 +3416,6 @@ static struct hci_conn *hci_low_sent(struct hci_dev *hdev, __u8 type,
 	struct hci_conn *conn = NULL, *c;
 	unsigned int num = 0, min = ~0;
 
-	/* We don't have to lock device here. Connections are always
-	 * added and removed with TX task disabled. */
-
 	rcu_read_lock();
 
 	list_for_each_entry_rcu(c, &h->list, list) {
@@ -3607,13 +3620,15 @@ static void __check_timeout(struct hci_dev *hdev, unsigned int cnt, u8 type)
 }
 
 /* Schedule SCO */
-static void hci_sched_sco(struct hci_dev *hdev, __u8 type)
+static void __hci_sched_sco(struct hci_dev *hdev, __u8 type)
 {
 	struct hci_conn *conn;
 	struct sk_buff *skb;
 	int quote, *cnt;
 	unsigned int pkts = hdev->sco_pkts;
 
+	lockdep_assert_held(&hdev->lock);
+
 	bt_dev_dbg(hdev, "type %u", type);
 
 	if (!hci_conn_num(hdev, type) || !pkts)
@@ -3648,6 +3663,13 @@ static void hci_sched_sco(struct hci_dev *hdev, __u8 type)
 		queue_work(hdev->workqueue, &hdev->tx_work);
 }
 
+static void hci_sched_sco(struct hci_dev *hdev, __u8 type)
+{
+	hci_dev_lock(hdev);
+	__hci_sched_sco(hdev, type);
+	hci_dev_unlock(hdev);
+}
+
 static void hci_sched_acl_pkt(struct hci_dev *hdev)
 {
 	unsigned int cnt = hdev->acl_cnt;
@@ -3657,6 +3679,8 @@ static void hci_sched_acl_pkt(struct hci_dev *hdev)
 
 	__check_timeout(hdev, cnt, ACL_LINK);
 
+	hci_dev_lock(hdev);
+
 	while (hdev->acl_cnt &&
 	       (chan = hci_chan_sent(hdev, ACL_LINK, &quote))) {
 		u32 priority = (skb_peek(&chan->data_q))->priority;
@@ -3681,13 +3705,15 @@ static void hci_sched_acl_pkt(struct hci_dev *hdev)
 			chan->conn->sent++;
 
 			/* Send pending SCO packets right away */
-			hci_sched_sco(hdev, SCO_LINK);
-			hci_sched_sco(hdev, ESCO_LINK);
+			__hci_sched_sco(hdev, SCO_LINK);
+			__hci_sched_sco(hdev, ESCO_LINK);
 		}
 	}
 
 	if (cnt != hdev->acl_cnt)
 		hci_prio_recalculate(hdev, ACL_LINK);
+
+	hci_dev_unlock(hdev);
 }
 
 static void hci_sched_acl(struct hci_dev *hdev)
@@ -3716,6 +3742,8 @@ static void hci_sched_le(struct hci_dev *hdev)
 
 	__check_timeout(hdev, *cnt, LE_LINK);
 
+	hci_dev_lock(hdev);
+
 	tmp = *cnt;
 	while (*cnt && (chan = hci_chan_sent(hdev, LE_LINK, &quote))) {
 		u32 priority = (skb_peek(&chan->data_q))->priority;
@@ -3737,13 +3765,15 @@ static void hci_sched_le(struct hci_dev *hdev)
 			chan->conn->sent++;
 
 			/* Send pending SCO packets right away */
-			hci_sched_sco(hdev, SCO_LINK);
-			hci_sched_sco(hdev, ESCO_LINK);
+			__hci_sched_sco(hdev, SCO_LINK);
+			__hci_sched_sco(hdev, ESCO_LINK);
 		}
 	}
 
 	if (*cnt != tmp)
 		hci_prio_recalculate(hdev, LE_LINK);
+
+	hci_dev_unlock(hdev);
 }
 
 /* Schedule iso */
@@ -3762,6 +3792,8 @@ static void hci_sched_iso(struct hci_dev *hdev, __u8 type)
 
 	__check_timeout(hdev, *cnt, type);
 
+	hci_dev_lock(hdev);
+
 	while (*cnt && (conn = hci_low_sent(hdev, type, &quote))) {
 		while (quote-- && (skb = skb_dequeue(&conn->data_q))) {
 			BT_DBG("skb %p len %d", skb, skb->len);
@@ -3775,6 +3807,8 @@ static void hci_sched_iso(struct hci_dev *hdev, __u8 type)
 			(*cnt)--;
 		}
 	}
+
+	hci_dev_unlock(hdev);
 }
 
 static void hci_tx_work(struct work_struct *work)
diff --git a/net/bluetooth/hci_debugfs.c b/net/bluetooth/hci_debugfs.c
--- a/net/bluetooth/hci_debugfs.c
+++ b/net/bluetooth/hci_debugfs.c
@@ -364,7 +364,7 @@ static int inquiry_cache_show(struct seq_file *f, void *p)
 
 	list_for_each_entry(e, &cache->all, all) {
 		struct inquiry_data *data = &e->data;
-		seq_printf(f, "%pMR %d %d %d 0x%.2x%.2x%.2x 0x%.4x %d %d %u\n",
+		seq_printf(f, "%pMR %d %d %d 0x%.2x%.2x%.2x 0x%.4x %d %d %lu\n",
 			   &data->bdaddr,
 			   data->pscan_rep_mode, data->pscan_period_mode,
 			   data->pscan_mode, data->dev_class[2],
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -312,6 +312,10 @@ static void hci_cmd_sync_work(struct work_struct *work)
 	while (1) {
 		struct hci_cmd_sync_work_entry *entry;
 
+		/* Leave the backlog to hci_cmd_sync_clear() */
+		if (hci_dev_test_flag(hdev, HCI_UNREGISTER))
+			break;
+
 		mutex_lock(&hdev->cmd_sync_work_lock);
 		entry = list_first_entry_or_null(&hdev->cmd_sync_work_list,
 						 struct hci_cmd_sync_work_entry,
@@ -658,6 +662,8 @@ void hci_cmd_sync_clear(struct hci_dev *hdev)
 {
 	struct hci_cmd_sync_work_entry *entry, *tmp;
 
+	/* cmd_work is disabled, the pending request can only time out */
+	hci_cmd_sync_cancel_sync(hdev, ENODEV);
 	cancel_work_sync(&hdev->cmd_sync_work);
 	cancel_work_sync(&hdev->reenable_adv_work);
 
@@ -5678,6 +5684,7 @@ int hci_stop_discovery_sync(struct hci_dev *hdev)
 {
 	struct discovery_state *d = &hdev->discovery;
 	struct inquiry_entry *e;
+	bdaddr_t addr;
 	int err;
 
 	bt_dev_dbg(hdev, "state %u", hdev->discovery.state);
@@ -5713,15 +5720,21 @@ int hci_stop_discovery_sync(struct hci_dev *hdev)
 		return 0;
 
 	if (d->state == DISCOVERY_RESOLVING || d->state == DISCOVERY_STOPPING) {
+		hci_dev_lock(hdev);
 		e = hci_inquiry_cache_lookup_resolve(hdev, BDADDR_ANY,
 						     NAME_PENDING);
-		if (!e)
+		if (!e) {
+			hci_dev_unlock(hdev);
 			return 0;
+		}
+
+		bacpy(&addr, &e->data.bdaddr);
+		hci_dev_unlock(hdev);
 
 		/* Ignore cancel errors since it should interfere with stopping
 		 * of the discovery.
 		 */
-		hci_remote_name_cancel_sync(hdev, &e->data.bdaddr);
+		hci_remote_name_cancel_sync(hdev, &addr);
 	}
 
 	return 0;
@@ -7151,6 +7164,7 @@ static int hci_acl_create_conn_sync(struct hci_dev *hdev, void *data)
 	bacpy(&cp.bdaddr, &conn->dst);
 	cp.pscan_rep_mode = 0x02;
 
+	hci_dev_lock(hdev);
 	ie = hci_inquiry_cache_lookup(hdev, &conn->dst);
 	if (ie) {
 		if (inquiry_entry_age(ie) <= INQUIRY_ENTRY_AGE_MAX) {
@@ -7162,6 +7176,7 @@ static int hci_acl_create_conn_sync(struct hci_dev *hdev, void *data)
 
 		memcpy(conn->dev_class, ie->data.dev_class, 3);
 	}
+	hci_dev_unlock(hdev);
 
 	cp.pkt_type = cpu_to_le16(conn->pkt_type);
 	if (lmp_rswitch_capable(hdev) && !(hdev->link_mode & HCI_LM_MASTER))
diff --git a/net/bluetooth/rfcomm/tty.c b/net/bluetooth/rfcomm/tty.c
--- a/net/bluetooth/rfcomm/tty.c
+++ b/net/bluetooth/rfcomm/tty.c
@@ -462,7 +462,7 @@ static int __rfcomm_release_dev(void __user *arg)
 	/* Shut down TTY synchronously before freeing rfcomm_dev */
 	tty_port_tty_vhangup(&dev->port);
 
-	if (!test_bit(RFCOMM_TTY_OWNED, &dev->status))
+	if (!test_and_set_bit(RFCOMM_TTY_OWNED, &dev->status))
 		tty_port_put(&dev->port);
 
 	tty_port_put(&dev->port);
@@ -724,10 +724,9 @@ static int rfcomm_tty_install(struct tty_driver *driver, struct tty_struct *tty)
 	 * when the last process closes the tty. The behaviour is expected by
 	 * userspace.
 	 */
-	if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags)) {
-		set_bit(RFCOMM_TTY_OWNED, &dev->status);
+	if (test_bit(RFCOMM_RELEASE_ONHUP, &dev->flags) &&
+	    !test_and_set_bit(RFCOMM_TTY_OWNED, &dev->status))
 		tty_port_put(&dev->port);
-	}
 
 	return 0;
 }
diff --git a/net/bluetooth/smp.c b/net/bluetooth/smp.c
--- a/net/bluetooth/smp.c
+++ b/net/bluetooth/smp.c
@@ -661,6 +661,7 @@ static void build_pairing_cmd(struct l2cap_conn *conn,
 		else
 			bdaddr_type = BDADDR_LE_RANDOM;
 
+		mutex_lock(&hdev->remote_oob_lock);
 		oob_data = hci_find_remote_oob_data(hdev, &hcon->dst,
 						    bdaddr_type);
 		if (oob_data && oob_data->present) {
@@ -671,6 +672,7 @@ static void build_pairing_cmd(struct l2cap_conn *conn,
 			SMP_DBG("OOB Remote Confirmation: %16phN", smp->pcnf);
 			SMP_DBG("OOB Remote Random: %16phN", smp->rr);
 		}
+		mutex_unlock(&hdev->remote_oob_lock);
 
 	} else {
 		authreq &= ~SMP_AUTH_SC;