13 files changed, 410 insertions, 125 deletions

diff --git a/net/bluetooth/af_bluetooth.c b/net/bluetooth/af_bluetooth.c
index 33d053d63407..1a6aa3f8d4d6 100644
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -154,6 +154,7 @@ struct sock *bt_sock_alloc(struct net *net, struct socket *sock,
 
 	sock_init_data(sock, sk);
 	INIT_LIST_HEAD(&bt_sk(sk)->accept_q);
+	spin_lock_init(&bt_sk(sk)->accept_q_lock);
 
 	sock_reset_flag(sk, SOCK_ZAPPED);
 
@@ -214,6 +215,7 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
 {
 	const struct cred *old_cred;
 	struct pid *old_pid;
+	struct bt_sock *par = bt_sk(parent);
 
 	BT_DBG("parent %p, sk %p", parent, sk);
 
@@ -224,9 +226,13 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
 	else
 		lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
 
-	list_add_tail(&bt_sk(sk)->accept_q, &bt_sk(parent)->accept_q);
 	bt_sk(sk)->parent = parent;
 
+	spin_lock_bh(&par->accept_q_lock);
+	list_add_tail(&bt_sk(sk)->accept_q, &par->accept_q);
+	sk_acceptq_added(parent);
+	spin_unlock_bh(&par->accept_q_lock);
+
 	/* Copy credentials from parent since for incoming connections the
 	 * socket is allocated by the kernel.
 	 */
@@ -244,8 +250,6 @@ void bt_accept_enqueue(struct sock *parent, struct sock *sk, bool bh)
 		bh_unlock_sock(sk);
 	else
 		release_sock(sk);
-
-	sk_acceptq_added(parent);
 }
 EXPORT_SYMBOL(bt_accept_enqueue);
 
@@ -254,45 +258,72 @@ EXPORT_SYMBOL(bt_accept_enqueue);
  */
 void bt_accept_unlink(struct sock *sk)
 {
+	struct sock *parent = bt_sk(sk)->parent;
+
 	BT_DBG("sk %p state %d", sk, sk->sk_state);
 
+	spin_lock_bh(&bt_sk(parent)->accept_q_lock);
 	list_del_init(&bt_sk(sk)->accept_q);
-	sk_acceptq_removed(bt_sk(sk)->parent);
+	sk_acceptq_removed(parent);
+	spin_unlock_bh(&bt_sk(parent)->accept_q_lock);
 	bt_sk(sk)->parent = NULL;
 	sock_put(sk);
 }
 EXPORT_SYMBOL(bt_accept_unlink);
 
+static struct sock *bt_accept_get(struct sock *parent, struct sock *sk)
+{
+	struct bt_sock *bt = bt_sk(parent);
+	struct sock *next = NULL;
+
+	/* accept_q is modified from child teardown paths too, so take a
+	 * temporary reference before dropping the queue lock.
+	 */
+	spin_lock_bh(&bt->accept_q_lock);
+
+	if (sk) {
+		if (bt_sk(sk)->parent != parent)
+			goto out;
+
+		if (!list_is_last(&bt_sk(sk)->accept_q, &bt->accept_q)) {
+			next = &list_next_entry(bt_sk(sk), accept_q)->sk;
+			sock_hold(next);
+		}
+	} else if (!list_empty(&bt->accept_q)) {
+		next = &list_first_entry(&bt->accept_q,
+					 struct bt_sock, accept_q)->sk;
+		sock_hold(next);
+	}
+
+out:
+	spin_unlock_bh(&bt->accept_q_lock);
+	return next;
+}
+
 struct sock *bt_accept_dequeue(struct sock *parent, struct socket *newsock)
 {
-	struct bt_sock *s, *n;
-	struct sock *sk;
+	struct sock *sk, *next;
 
 	BT_DBG("parent %p", parent);
 
 restart:
-	list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) {
-		sk = (struct sock *)s;
-
+	for (sk = bt_accept_get(parent, NULL); sk; sk = next) {
 		/* Prevent early freeing of sk due to unlink and sock_kill */
-		sock_hold(sk);
 		lock_sock(sk);
 
 		/* Check sk has not already been unlinked via
 		 * bt_accept_unlink() due to serialisation caused by sk locking
 		 */
-		if (!bt_sk(sk)->parent) {
+		if (bt_sk(sk)->parent != parent) {
 			BT_DBG("sk %p, already unlinked", sk);
 			release_sock(sk);
 			sock_put(sk);
 
-			/* Restart the loop as sk is no longer in the list
-			 * and also avoid a potential infinite loop because
-			 * list_for_each_entry_safe() is not thread safe.
-			 */
 			goto restart;
 		}
 
+		next = bt_accept_get(parent, sk);
+
 		/* sk is safely in the parent list so reduce reference count */
 		sock_put(sk);
 
@@ -309,7 +340,19 @@ restart:
 			if (newsock)
 				sock_graft(sk, newsock);
 
+			/* Hand the caller a reference taken while sk is
+			 * still locked.  bt_accept_unlink() just dropped
+			 * the accept-queue reference; without this hold a
+			 * concurrent teardown (e.g. l2cap_conn_del() ->
+			 * l2cap_sock_kill()) could free sk between
+			 * release_sock() and the caller using it.  Every
+			 * caller drops this with sock_put() when done.
+			 */
+			sock_hold(sk);
+
 			release_sock(sk);
+			if (next)
+				sock_put(next);
 			return sk;
 		}
 
@@ -518,18 +561,28 @@ EXPORT_SYMBOL(bt_sock_stream_recvmsg);
 
 static inline __poll_t bt_accept_poll(struct sock *parent)
 {
-	struct bt_sock *s, *n;
+	struct bt_sock *bt = bt_sk(parent);
+	struct bt_sock *s;
 	struct sock *sk;
+	__poll_t mask = 0;
+
+	spin_lock_bh(&bt->accept_q_lock);
+	list_for_each_entry(s, &bt->accept_q, accept_q) {
+		int state;
 
-	list_for_each_entry_safe(s, n, &bt_sk(parent)->accept_q, accept_q) {
 		sk = (struct sock *)s;
-		if (sk->sk_state == BT_CONNECTED ||
-		    (test_bit(BT_SK_DEFER_SETUP, &bt_sk(parent)->flags) &&
-		     sk->sk_state == BT_CONNECT2))
-			return EPOLLIN | EPOLLRDNORM;
+		state = READ_ONCE(sk->sk_state);
+
+		if (state == BT_CONNECTED ||
+		    (test_bit(BT_SK_DEFER_SETUP, &bt->flags) &&
+		     state == BT_CONNECT2)) {
+			mask = EPOLLIN | EPOLLRDNORM;
+			break;
+		}
 	}
+	spin_unlock_bh(&bt->accept_q_lock);
 
-	return 0;
+	return mask;
 }
 
 __poll_t bt_sock_poll(struct file *file, struct socket *sock,
diff --git a/net/bluetooth/bnep/core.c b/net/bluetooth/bnep/core.c
index d44987d4515c..0de5df690bd0 100644
--- a/net/bluetooth/bnep/core.c
+++ b/net/bluetooth/bnep/core.c
@@ -330,11 +330,18 @@ static int bnep_rx_frame(struct bnep_session *s, struct sk_buff *skb)
 				goto badframe;
 			break;
 		case BNEP_FILTER_MULTI_ADDR_SET:
-		case BNEP_FILTER_NET_TYPE_SET:
-			/* Pull: ctrl type (1 b), len (2 b), data (len bytes) */
-			if (!skb_pull(skb, 3 + *(u16 *)(skb->data + 1) * 2))
+		case BNEP_FILTER_NET_TYPE_SET: {
+			u8 *hdr;
+
+			/* Pull ctrl type (1 b) + len (2 b) */
+			hdr = skb_pull_data(skb, 3);
+			if (!hdr)
+				goto badframe;
+			/* Pull data (len bytes); length is big-endian */
+			if (!skb_pull(skb, get_unaligned_be16(&hdr[1])))
 				goto badframe;
 			break;
+		}
 		default:
 			kfree_skb(skb);
 			return 0;
@@ -638,8 +645,8 @@ int bnep_add_connection(struct bnep_connadd_req *req, struct socket *sock)
 		goto failed;
 	}
 
-	up_write(&bnep_session_sem);
 	strcpy(req->device, dev->name);
+	up_write(&bnep_session_sem);
 	return 0;
 
 failed:
diff --git a/net/bluetooth/hci_conn.c b/net/bluetooth/hci_conn.c
index 3a0592599086..17b46ad6a349 100644
--- a/net/bluetooth/hci_conn.c
+++ b/net/bluetooth/hci_conn.c
@@ -480,40 +480,107 @@ bool hci_setup_sync(struct hci_conn *conn, __u16 handle)
 	return hci_setup_sync_conn(conn, handle);
 }
 
-u8 hci_le_conn_update(struct hci_conn *conn, u16 min, u16 max, u16 latency,
-		      u16 to_multiplier)
+struct le_conn_update_data {
+	struct hci_conn *conn;
+	u16	min;
+	u16	max;
+	u16	latency;
+	u16	to_multiplier;
+};
+
+static int le_conn_update_sync(struct hci_dev *hdev, void *data)
 {
-	struct hci_dev *hdev = conn->hdev;
+	struct le_conn_update_data *d = data;
+	struct hci_conn *conn = d->conn;
 	struct hci_conn_params *params;
 	struct hci_cp_le_conn_update cp;
+	u16 timeout;
+	u8 store_hint;
+	int err;
 
+	/* Verify connection is still alive and read conn fields under
+	 * the same lock to prevent a concurrent disconnect from freeing
+	 * or reusing the connection while we build the HCI command.
+	 */
 	hci_dev_lock(hdev);
 
-	params = hci_conn_params_lookup(hdev, &conn->dst, conn->dst_type);
-	if (params) {
-		params->conn_min_interval = min;
-		params->conn_max_interval = max;
-		params->conn_latency = latency;
-		params->supervision_timeout = to_multiplier;
+	if (!hci_conn_valid(hdev, conn)) {
+		hci_dev_unlock(hdev);
+		return -ECANCELED;
 	}
 
-	hci_dev_unlock(hdev);
-
 	memset(&cp, 0, sizeof(cp));
 	cp.handle		= cpu_to_le16(conn->handle);
-	cp.conn_interval_min	= cpu_to_le16(min);
-	cp.conn_interval_max	= cpu_to_le16(max);
-	cp.conn_latency		= cpu_to_le16(latency);
-	cp.supervision_timeout	= cpu_to_le16(to_multiplier);
+	cp.conn_interval_min	= cpu_to_le16(d->min);
+	cp.conn_interval_max	= cpu_to_le16(d->max);
+	cp.conn_latency		= cpu_to_le16(d->latency);
+	cp.supervision_timeout	= cpu_to_le16(d->to_multiplier);
 	cp.min_ce_len		= cpu_to_le16(0x0000);
 	cp.max_ce_len		= cpu_to_le16(0x0000);
+	timeout			= conn->conn_timeout;
+
+	hci_dev_unlock(hdev);
 
-	hci_send_cmd(hdev, HCI_OP_LE_CONN_UPDATE, sizeof(cp), &cp);
+	err = __hci_cmd_sync_status_sk(hdev, HCI_OP_LE_CONN_UPDATE,
+				       sizeof(cp), &cp,
+				       HCI_EV_LE_CONN_UPDATE_COMPLETE,
+				       timeout, NULL);
+	if (err)
+		return err;
+
+	/* Update stored connection parameters after the controller has
+	 * confirmed the update via the LE Connection Update Complete event.
+	 */
+	hci_dev_lock(hdev);
+
+	params = hci_conn_params_lookup(hdev, &conn->dst, conn->dst_type);
+	if (params) {
+		params->conn_min_interval = d->min;
+		params->conn_max_interval = d->max;
+		params->conn_latency = d->latency;
+		params->supervision_timeout = d->to_multiplier;
+		store_hint = 0x01;
+	} else {
+		store_hint = 0x00;
+	}
 
-	if (params)
-		return 0x01;
+	hci_dev_unlock(hdev);
 
-	return 0x00;
+	mgmt_new_conn_param(hdev, &conn->dst, conn->dst_type, store_hint,
+			    d->min, d->max, d->latency, d->to_multiplier);
+
+	return 0;
+}
+
+static void le_conn_update_complete(struct hci_dev *hdev, void *data, int err)
+{
+	struct le_conn_update_data *d = data;
+
+	hci_conn_put(d->conn);
+	kfree(d);
+}
+
+void hci_le_conn_update(struct hci_conn *conn, u16 min, u16 max, u16 latency,
+			u16 to_multiplier)
+{
+	struct le_conn_update_data *d;
+
+	d = kzalloc_obj(*d);
+	if (!d)
+		return;
+
+	hci_conn_get(conn);
+	d->conn = conn;
+	d->min = min;
+	d->max = max;
+	d->latency = latency;
+	d->to_multiplier = to_multiplier;
+
+	if (hci_cmd_sync_queue(conn->hdev, le_conn_update_sync, d,
+			       le_conn_update_complete) < 0) {
+		hci_conn_put(conn);
+		kfree(d);
+	}
 }
 
 void hci_le_start_enc(struct hci_conn *conn, __le16 ediv, __le64 rand,
@@ -2130,6 +2197,9 @@ static int create_big_sync(struct hci_dev *hdev, void *data)
 	u32 flags = 0;
 	int err;
 
+	if (!hci_conn_valid(hdev, conn))
+		return -ECANCELED;
+
 	if (qos->bcast.out.phys == BIT(1))
 		flags |= MGMT_ADV_FLAG_SEC_2M;
 
@@ -2204,11 +2274,24 @@ static void create_big_complete(struct hci_dev *hdev, void *data, int err)
 
 	bt_dev_dbg(hdev, "conn %p", conn);
 
+	if (err == -ECANCELED)
+		goto done;
+
+	hci_dev_lock(hdev);
+
+	if (!hci_conn_valid(hdev, conn))
+		goto unlock;
+
 	if (err) {
 		bt_dev_err(hdev, "Unable to create BIG: %d", err);
 		hci_connect_cfm(conn, err);
 		hci_conn_del(conn);
 	}
+
+unlock:
+	hci_dev_unlock(hdev);
+done:
+	hci_conn_put(conn);
 }
 
 struct hci_conn *hci_bind_bis(struct hci_dev *hdev, bdaddr_t *dst, __u8 sid,
@@ -2336,10 +2419,11 @@ struct hci_conn *hci_connect_bis(struct hci_dev *hdev, bdaddr_t *dst,
 				 BT_BOUND, &data);
 
 	/* Queue start periodic advertising and create BIG */
-	err = hci_cmd_sync_queue(hdev, create_big_sync, conn,
+	err = hci_cmd_sync_queue(hdev, create_big_sync, hci_conn_get(conn),
 				 create_big_complete);
 	if (err < 0) {
 		hci_conn_drop(conn);
+		hci_conn_put(conn);
 		return ERR_PTR(err);
 	}
 
diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c
index b2ee6b6a0f56..eea2f810aafa 100644
--- a/net/bluetooth/hci_event.c
+++ b/net/bluetooth/hci_event.c
@@ -7118,9 +7118,29 @@ static void hci_le_create_big_complete_evt(struct hci_dev *hdev, void *data,
 			continue;
 		}
 
+		if (ev->num_bis <= i) {
+			bt_dev_err(hdev,
+				   "Not enough BIS handles for BIG 0x%2.2x",
+				   ev->handle);
+			ev->status = HCI_ERROR_UNSPECIFIED;
+			hci_connect_cfm(conn, ev->status);
+			hci_conn_del(conn);
+			continue;
+		}
+
 		if (hci_conn_set_handle(conn,
-					__le16_to_cpu(ev->bis_handle[i++])))
+					__le16_to_cpu(ev->bis_handle[i++]))) {
+			bt_dev_err(hdev,
+				   "Failed to set BIS handle for BIG 0x%2.2x",
+				   ev->handle);
+			/* Force error so BIG gets terminated as not all BIS
+			 * could be connected.
+			 */
+			ev->status = HCI_ERROR_UNSPECIFIED;
+			hci_connect_cfm(conn, ev->status);
+			hci_conn_del(conn);
 			continue;
+		}
 
 		conn->state = BT_CONNECTED;
 		set_bit(HCI_CONN_BIG_CREATED, &conn->flags);
@@ -7129,7 +7149,10 @@ static void hci_le_create_big_complete_evt(struct hci_dev *hdev, void *data,
 		hci_iso_setup_path(conn);
 	}
 
-	if (!ev->status && !i)
+	/* If there is an unexpected error or if no BISes have been connected
+	 * for the BIG, terminate it.
+	 */
+	if (ev->status == HCI_ERROR_UNSPECIFIED || (!ev->status && !i))
 		/* If no BISes have been connected for the BIG,
 		 * terminate. This is in case all bound connections
 		 * have been closed before the BIG creation
@@ -7168,7 +7191,7 @@ static void hci_le_big_sync_established_evt(struct hci_dev *hdev, void *data,
 	clear_bit(HCI_CONN_CREATE_BIG_SYNC, &conn->flags);
 
 	conn->num_bis = 0;
-	memset(conn->bis, 0, sizeof(conn->num_bis));
+	memset(conn->bis, 0, sizeof(conn->bis));
 
 	for (i = 0; i < ev->num_bis; i++) {
 		u16 handle = le16_to_cpu(ev->bis[i]);
diff --git a/net/bluetooth/hci_sync.c b/net/bluetooth/hci_sync.c
index fd3aacdea512..aff8562a8690 100644
--- a/net/bluetooth/hci_sync.c
+++ b/net/bluetooth/hci_sync.c
@@ -4438,6 +4438,9 @@ static int hci_le_set_event_mask_sync(struct hci_dev *hdev)
 		events[4] |= 0x02;	/* LE BIG Info Advertising Report */
 	}
 
+	if (ll_ext_feature_capable(hdev))
+		events[5] |= BIT(2);
+
 	if (le_cs_capable(hdev)) {
 		/* Channel Sounding events */
 		events[5] |= 0x08;	/* LE CS Read Remote Supported Cap Complete event */
@@ -7413,9 +7416,6 @@ static int hci_le_read_all_remote_features_sync(struct hci_dev *hdev,
 					sizeof(cp), &cp,
 					HCI_EVT_LE_ALL_REMOTE_FEATURES_COMPLETE,
 					HCI_CMD_TIMEOUT, NULL);
-
-	return __hci_cmd_sync_status(hdev, HCI_OP_LE_READ_ALL_REMOTE_FEATURES,
-				     sizeof(cp), &cp, HCI_CMD_TIMEOUT);
 }
 
 static int hci_le_read_remote_features_sync(struct hci_dev *hdev, void *data)
diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c
index 7bcf8c5ceaee..976f91eeb745 100644
--- a/net/bluetooth/hidp/core.c
+++ b/net/bluetooth/hidp/core.c
@@ -1036,6 +1036,28 @@ static struct hidp_session *hidp_session_find(const bdaddr_t *bdaddr)
 }
 
 /*
+ * Consume session->conn: clear the member under hidp_session_sem, then
+ * l2cap_unregister_user() and l2cap_conn_put() the snapshot outside the
+ * sem.  At most one caller wins; later callers see NULL and skip.  The
+ * reference is the one hidp_session_new() took via l2cap_conn_get().
+ */
+static void hidp_session_unregister_conn(struct hidp_session *session)
+{
+	struct l2cap_conn *conn;
+
+	down_write(&hidp_session_sem);
+	conn = session->conn;
+	if (conn)
+		session->conn = NULL;
+	up_write(&hidp_session_sem);
+
+	if (conn) {
+		l2cap_unregister_user(conn, &session->user);
+		l2cap_conn_put(conn);
+	}
+}
+
+/*
  * Start session synchronously
  * This starts a session thread and waits until initialization
  * is done or returns an error if it couldn't be started.
@@ -1311,8 +1333,7 @@ static int hidp_session_thread(void *arg)
 	 * Instead, this call has the same semantics as if user-space tried to
 	 * delete the session.
 	 */
-	if (session->conn)
-		l2cap_unregister_user(session->conn, &session->user);
+	hidp_session_unregister_conn(session);
 
 	hidp_session_put(session);
 
@@ -1418,7 +1439,7 @@ int hidp_connection_del(struct hidp_conndel_req *req)
 				         HIDP_CTRL_VIRTUAL_CABLE_UNPLUG,
 				       NULL, 0);
 	else
-		l2cap_unregister_user(session->conn, &session->user);
+		hidp_session_unregister_conn(session);
 
 	hidp_session_put(session);
 
diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index be145e2736b7..d7af617cda45 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -347,6 +347,7 @@ static int iso_connect_bis(struct sock *sk)
 		return -EHOSTUNREACH;
 
 	hci_dev_lock(hdev);
+	lock_sock(sk);
 
 	if (!bis_capable(hdev)) {
 		err = -EOPNOTSUPP;
@@ -399,13 +400,9 @@ static int iso_connect_bis(struct sock *sk)
 		goto unlock;
 	}
 
-	lock_sock(sk);
-
 	err = iso_chan_add(conn, sk, NULL);
-	if (err) {
-		release_sock(sk);
+	if (err)
 		goto unlock;
-	}
 
 	/* Update source addr of the socket */
 	bacpy(&iso_pi(sk)->src, &hcon->src);
@@ -421,9 +418,8 @@ static int iso_connect_bis(struct sock *sk)
 		iso_sock_set_timer(sk, READ_ONCE(sk->sk_sndtimeo));
 	}
 
-	release_sock(sk);
-
 unlock:
+	release_sock(sk);
 	hci_dev_unlock(hdev);
 	hci_dev_put(hdev);
 	return err;
@@ -444,6 +440,7 @@ static int iso_connect_cis(struct sock *sk)
 		return -EHOSTUNREACH;
 
 	hci_dev_lock(hdev);
+	lock_sock(sk);
 
 	if (!cis_central_capable(hdev)) {
 		err = -EOPNOTSUPP;
@@ -498,13 +495,9 @@ static int iso_connect_cis(struct sock *sk)
 		goto unlock;
 	}
 
-	lock_sock(sk);
-
 	err = iso_chan_add(conn, sk, NULL);
-	if (err) {
-		release_sock(sk);
+	if (err)
 		goto unlock;
-	}
 
 	/* Update source addr of the socket */
 	bacpy(&iso_pi(sk)->src, &hcon->src);
@@ -520,9 +513,8 @@ static int iso_connect_cis(struct sock *sk)
 		iso_sock_set_timer(sk, READ_ONCE(sk->sk_sndtimeo));
 	}
 
-	release_sock(sk);
-
 unlock:
+	release_sock(sk);
 	hci_dev_unlock(hdev);
 	hci_dev_put(hdev);
 	return err;
@@ -759,6 +751,8 @@ static void iso_sock_cleanup_listen(struct sock *parent)
 	while ((sk = bt_accept_dequeue(parent, NULL))) {
 		iso_sock_close(sk);
 		iso_sock_kill(sk);
+		/* Drop the reference handed back by bt_accept_dequeue(). */
+		sock_put(sk);
 	}
 
 	/* If listening socket has a hcon, properly disconnect it */
@@ -1193,7 +1187,7 @@ static int iso_sock_connect(struct socket *sock, struct sockaddr_unsized *addr,
 
 	release_sock(sk);
 
-	if (bacmp(&iso_pi(sk)->dst, BDADDR_ANY))
+	if (bacmp(&sa->iso_bdaddr, BDADDR_ANY))
 		err = iso_connect_cis(sk);
 	else
 		err = iso_connect_bis(sk);
@@ -1364,8 +1358,13 @@ static int iso_sock_accept(struct socket *sock, struct socket *newsock,
 		}
 
 		ch = bt_accept_dequeue(sk, newsock);
-		if (ch)
+		if (ch) {
+			/* Drop the bridging ref from bt_accept_dequeue();
+			 * the grafted socket keeps ch alive from here.
+			 */
+			sock_put(ch);
 			break;
+		}
 
 		if (!timeo) {
 			err = -EAGAIN;
@@ -2256,8 +2255,10 @@ int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags)
 		sk = iso_get_sock(hdev, &hdev->bdaddr, bdaddr, BT_LISTEN,
 				  iso_match_sid, ev1);
 		if (sk && !ev1->status) {
+			lock_sock(sk);
 			iso_pi(sk)->sync_handle = le16_to_cpu(ev1->handle);
 			iso_pi(sk)->bc_sid = ev1->sid;
+			release_sock(sk);
 		}
 
 		goto done;
@@ -2268,8 +2269,10 @@ int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags)
 		sk = iso_get_sock(hdev, &hdev->bdaddr, bdaddr, BT_LISTEN,
 				  iso_match_sid_past, ev1a);
 		if (sk && !ev1a->status) {
+			lock_sock(sk);
 			iso_pi(sk)->sync_handle = le16_to_cpu(ev1a->sync_handle);
 			iso_pi(sk)->bc_sid = ev1a->sid;
+			release_sock(sk);
 		}
 
 		goto done;
@@ -2296,27 +2299,35 @@ int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags)
 					  ev2);
 
 		if (sk) {
-			int err;
-			struct hci_conn	*hcon = iso_pi(sk)->conn->hcon;
+			int err = 0;
+			bool big_sync;
+			struct hci_conn *hcon;
 
+			lock_sock(sk);
+
+			hcon = iso_pi(sk)->conn->hcon;
 			iso_pi(sk)->qos.bcast.encryption = ev2->encryption;
 
 			if (ev2->num_bis < iso_pi(sk)->bc_num_bis)
 				iso_pi(sk)->bc_num_bis = ev2->num_bis;
 
-			if (!test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags) &&
-			    !test_and_set_bit(BT_SK_BIG_SYNC, &iso_pi(sk)->flags)) {
+			big_sync = !test_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags) &&
+				   !test_and_set_bit(BT_SK_BIG_SYNC, &iso_pi(sk)->flags);
+
+			if (big_sync)
 				err = hci_conn_big_create_sync(hdev, hcon,
 							       &iso_pi(sk)->qos,
 							       iso_pi(sk)->sync_handle,
 							       iso_pi(sk)->bc_num_bis,
 							       iso_pi(sk)->bc_bis);
-				if (err) {
-					bt_dev_err(hdev, "hci_le_big_create_sync: %d",
-						   err);
-					sock_put(sk);
-					sk = NULL;
-				}
+
+			release_sock(sk);
+
+			if (big_sync && err) {
+				bt_dev_err(hdev, "hci_le_big_create_sync: %d",
+					   err);
+				sock_put(sk);
+				sk = NULL;
 			}
 		}
 
@@ -2370,8 +2381,10 @@ int iso_connect_ind(struct hci_dev *hdev, bdaddr_t *bdaddr, __u8 *flags)
 			if (!base || base_len > BASE_MAX_LENGTH)
 				goto done;
 
+			lock_sock(sk);
 			memcpy(iso_pi(sk)->base, base, base_len);
 			iso_pi(sk)->base_len = base_len;
+			release_sock(sk);
 		} else {
 			/* This is a PA data fragment. Keep pa_data_len set to 0
 			 * until all data has been reassembled.
@@ -2587,6 +2600,11 @@ int iso_recv(struct hci_dev *hdev, u16 handle, struct sk_buff *skb, u16 flags)
 		break;
 
 	case ISO_END:
+		if (!conn->rx_len) {
+			BT_ERR("Unexpected end frame (len %d)", skb->len);
+			goto drop;
+		}
+
 		skb_copy_from_linear_data(skb, skb_put(conn->rx_skb, skb->len),
 					  skb->len);
 		conn->rx_len -= skb->len;
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 77dec104a9c3..fdccd62ccca8 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4706,16 +4706,8 @@ static inline int l2cap_conn_param_update_req(struct l2cap_conn *conn,
 	l2cap_send_cmd(conn, cmd->ident, L2CAP_CONN_PARAM_UPDATE_RSP,
 		       sizeof(rsp), &rsp);
 
-	if (!err) {
-		u8 store_hint;
-
-		store_hint = hci_le_conn_update(hcon, min, max, latency,
-						to_multiplier);
-		mgmt_new_conn_param(hcon->hdev, &hcon->dst, hcon->dst_type,
-				    store_hint, min, max, latency,
-				    to_multiplier);
-
-	}
+	if (!err)
+		hci_le_conn_update(hcon, min, max, latency, to_multiplier);
 
 	return 0;
 }
@@ -5428,7 +5420,7 @@ static inline int l2cap_ecred_reconf_req(struct l2cap_conn *conn,
 		 * configured, the MPS field may be less than the current MPS
 		 * of that channel.
 		 */
-		if (chan[i]->remote_mps >= mps && i) {
+		if (chan[i]->remote_mps > mps && num_scid > 1) {
 			BT_ERR("chan %p decreased MPS %u -> %u", chan[i],
 			       chan[i]->remote_mps, mps);
 			result = L2CAP_RECONF_INVALID_MPS;
@@ -7282,7 +7274,7 @@ static void l2cap_ecred_reconfigure(struct l2cap_chan *chan)
 	chan->ident = l2cap_get_ident(conn);
 
 	l2cap_send_cmd(conn, chan->ident, L2CAP_ECRED_RECONF_REQ,
-		       sizeof(pdu), &pdu);
+		       struct_size(pdu, scid, 1), pdu);
 }
 
 int l2cap_chan_reconfigure(struct l2cap_chan *chan, __u16 mtu)
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
index 71e8c1b45bce..b34e7da8d906 100644
--- a/net/bluetooth/l2cap_sock.c
+++ b/net/bluetooth/l2cap_sock.c
@@ -349,8 +349,13 @@ static int l2cap_sock_accept(struct socket *sock, struct socket *newsock,
 		}
 
 		nsk = bt_accept_dequeue(sk, newsock);
-		if (nsk)
+		if (nsk) {
+			/* Drop the bridging ref from bt_accept_dequeue();
+			 * the grafted socket keeps nsk alive from here.
+			 */
+			sock_put(nsk);
 			break;
+		}
 
 		if (!timeo) {
 			err = -EAGAIN;
@@ -1475,22 +1480,54 @@ static void l2cap_sock_cleanup_listen(struct sock *parent)
 	BT_DBG("parent %p state %s", parent,
 	       state_to_string(parent->sk_state));
 
-	/* Close not yet accepted channels */
+	/* Close not yet accepted channels.
+	 *
+	 * bt_accept_dequeue() now returns sk with an extra reference held
+	 * (taken while sk was still locked) so a concurrent l2cap_conn_del()
+	 * -> l2cap_sock_kill() cannot free sk under us.
+	 *
+	 * cleanup_listen() runs under the parent sk lock, so unlike
+	 * l2cap_sock_shutdown() we must NOT take conn->lock here: that would
+	 * establish sk_lock -> conn->lock and invert the established
+	 * conn->lock -> chan->lock -> sk_lock order (lockdep deadlock).
+	 *
+	 * Instead, briefly take the child sk lock to fetch and pin its chan.
+	 * l2cap_conn_del() reaches the chan free only via
+	 * l2cap_chan_del() -> l2cap_sock_teardown_cb(), which itself takes
+	 * the child sk lock; holding it across l2cap_chan_hold_unless_zero()
+	 * therefore guarantees the chan cannot be freed while we read and
+	 * pin it (hold_unless_zero() additionally skips a chan already past
+	 * its last reference).  We then drop the sk lock before taking
+	 * chan->lock, so sk and chan locks are never held together.
+	 */
 	while ((sk = bt_accept_dequeue(parent, NULL))) {
-		struct l2cap_chan *chan = l2cap_pi(sk)->chan;
+		struct l2cap_chan *chan;
+
+		lock_sock_nested(sk, L2CAP_NESTING_NORMAL);
+		chan = l2cap_chan_hold_unless_zero(l2cap_pi(sk)->chan);
+		release_sock(sk);
+		if (!chan) {
+			/* l2cap_conn_del() already tearing this child down */
+			sock_put(sk);
+			continue;
+		}
 
 		BT_DBG("child chan %p state %s", chan,
 		       state_to_string(chan->state));
 
-		l2cap_chan_hold(chan);
 		l2cap_chan_lock(chan);
-
 		__clear_chan_timer(chan);
 		l2cap_chan_close(chan, ECONNRESET);
-		l2cap_sock_kill(sk);
-
+		/* l2cap_conn_del() may already have killed this socket
+		 * (it sets SOCK_DEAD); skip the duplicate to avoid a
+		 * double sock_put()/l2cap_chan_put().
+		 */
+		if (!sock_flag(sk, SOCK_DEAD))
+			l2cap_sock_kill(sk);
 		l2cap_chan_unlock(chan);
+
 		l2cap_chan_put(chan);
+		sock_put(sk);
 	}
 }
 
@@ -1498,6 +1535,9 @@ static struct l2cap_chan *l2cap_sock_new_connection_cb(struct l2cap_chan *chan)
 {
 	struct sock *sk, *parent = chan->data;
 
+	if (!parent)
+		return NULL;
+
 	lock_sock(parent);
 
 	/* Check for backlog size */
@@ -1657,6 +1697,9 @@ static void l2cap_sock_state_change_cb(struct l2cap_chan *chan, int state,
 {
 	struct sock *sk = chan->data;
 
+	if (!sk)
+		return;
+
 	sk->sk_state = state;
 
 	if (err)
@@ -1758,6 +1801,9 @@ static long l2cap_sock_get_sndtimeo_cb(struct l2cap_chan *chan)
 {
 	struct sock *sk = chan->data;
 
+	if (!sk)
+		return 0;
+
 	return READ_ONCE(sk->sk_sndtimeo);
 }
 
diff --git a/net/bluetooth/mgmt.c b/net/bluetooth/mgmt.c
index b05bb380e5f8..de5bd6b637b2 100644
--- a/net/bluetooth/mgmt.c
+++ b/net/bluetooth/mgmt.c
@@ -9110,9 +9110,15 @@ static int add_ext_adv_data(struct sock *sk, struct hci_dev *hdev, void *data,
 	struct adv_info *adv_instance;
 	int err = 0;
 	struct mgmt_pending_cmd *cmd;
+	u16 expected_len;
 
 	BT_DBG("%s", hdev->name);
 
+	expected_len = struct_size(cp, data, cp->adv_data_len + cp->scan_rsp_len);
+	if (expected_len != data_len)
+		return mgmt_cmd_status(sk, hdev->id, MGMT_OP_ADD_EXT_ADV_DATA,
+				       MGMT_STATUS_INVALID_PARAMS);
+
 	hci_dev_lock(hdev);
 
 	adv_instance = hci_find_adv_instance(hdev, cp->instance);
diff --git a/net/bluetooth/rfcomm/core.c b/net/bluetooth/rfcomm/core.c
index 611a9a94151e..d11bd5337d57 100644
--- a/net/bluetooth/rfcomm/core.c
+++ b/net/bluetooth/rfcomm/core.c
@@ -1715,9 +1715,12 @@ static int rfcomm_recv_data(struct rfcomm_session *s, u8 dlci, int pf, struct sk
 	}
 
 	if (pf && d->cfc) {
-		u8 credits = *(u8 *) skb->data; skb_pull(skb, 1);
+		u8 *credits = skb_pull_data(skb, 1);
 
-		d->tx_credits += credits;
+		if (!credits)
+			goto drop;
+
+		d->tx_credits += *credits;
 		if (d->tx_credits)
 			clear_bit(RFCOMM_TX_THROTTLED, &d->flags);
 	}
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index be6639cd6f59..bd7d959c6e9e 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -180,6 +180,8 @@ static void rfcomm_sock_cleanup_listen(struct sock *parent)
 	while ((sk = bt_accept_dequeue(parent, NULL))) {
 		rfcomm_sock_close(sk);
 		rfcomm_sock_kill(sk);
+		/* Drop the reference handed back by bt_accept_dequeue(). */
+		sock_put(sk);
 	}
 
 	parent->sk_state  = BT_CLOSED;
@@ -497,8 +499,13 @@ static int rfcomm_sock_accept(struct socket *sock, struct socket *newsock,
 		}
 
 		nsk = bt_accept_dequeue(sk, newsock);
-		if (nsk)
+		if (nsk) {
+			/* Drop the bridging ref from bt_accept_dequeue();
+			 * the grafted socket keeps nsk alive from here.
+			 */
+			sock_put(nsk);
 			break;
+		}
 
 		if (!timeo) {
 			err = -EAGAIN;
diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
index 18826d4b9c0b..f1799c6a6f87 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -472,9 +472,13 @@ static struct sock *sco_get_sock_listen(bdaddr_t *src)
 			sk1 = sk;
 	}
 
+	sk = sk ? sk : sk1;
+	if (sk)
+		sock_hold(sk);
+
 	read_unlock(&sco_sk_list.lock);
 
-	return sk ? sk : sk1;
+	return sk;
 }
 
 static void sco_sock_destruct(struct sock *sk)
@@ -498,6 +502,8 @@ static void sco_sock_cleanup_listen(struct sock *parent)
 	while ((sk = bt_accept_dequeue(parent, NULL))) {
 		sco_sock_close(sk);
 		sco_sock_kill(sk);
+		/* Drop the reference handed back by bt_accept_dequeue(). */
+		sock_put(sk);
 	}
 
 	parent->sk_state  = BT_CLOSED;
@@ -515,11 +521,13 @@ static void sco_sock_kill(struct sock *sk)
 	BT_DBG("sk %p state %d", sk, sk->sk_state);
 
 	/* Sock is dead, so set conn->sk to NULL to avoid possible UAF */
+	lock_sock(sk);
 	if (sco_pi(sk)->conn) {
 		sco_conn_lock(sco_pi(sk)->conn);
 		sco_pi(sk)->conn->sk = NULL;
 		sco_conn_unlock(sco_pi(sk)->conn);
 	}
+	release_sock(sk);
 
 	/* Kill poor orphan */
 	bt_sock_unlink(&sco_sk_list, sk);
@@ -759,8 +767,13 @@ static int sco_sock_accept(struct socket *sock, struct socket *newsock,
 		}
 
 		ch = bt_accept_dequeue(sk, newsock);
-		if (ch)
+		if (ch) {
+			/* Drop the bridging ref from bt_accept_dequeue();
+			 * the grafted socket keeps ch alive from here.
+			 */
+			sock_put(ch);
 			break;
+		}
 
 		if (!timeo) {
 			err = -EAGAIN;
@@ -1365,40 +1378,51 @@ static int sco_sock_release(struct socket *sock)
 
 static void sco_conn_ready(struct sco_conn *conn)
 {
-	struct sock *parent;
-	struct sock *sk = conn->sk;
+	struct sock *parent, *sk;
+
+	sco_conn_lock(conn);
+	sk = sco_sock_hold(conn);
+	sco_conn_unlock(conn);
 
 	BT_DBG("conn %p", conn);
 
 	if (sk) {
 		lock_sock(sk);
-		sco_sock_clear_timer(sk);
-		sk->sk_state = BT_CONNECTED;
-		sk->sk_state_change(sk);
+
+		/* conn->sk may have become NULL if racing with sk close, but
+		 * due to held hdev->lock, it can't become different sk.
+		 */
+		if (conn->sk) {
+			sco_sock_clear_timer(sk);
+			sk->sk_state = BT_CONNECTED;
+			sk->sk_state_change(sk);
+		}
+
 		release_sock(sk);
+		sock_put(sk);
 	} else {
-		sco_conn_lock(conn);
-
-		if (!conn->hcon) {
-			sco_conn_unlock(conn);
+		if (!conn->hcon)
 			return;
-		}
+
+		lockdep_assert_held(&conn->hcon->hdev->lock);
 
 		parent = sco_get_sock_listen(&conn->hcon->src);
-		if (!parent) {
-			sco_conn_unlock(conn);
+		if (!parent)
 			return;
-		}
 
 		lock_sock(parent);
 
+		sco_conn_lock(conn);
+
+		/* hdev->lock guarantees conn->sk == NULL still here */
+
+		if (parent->sk_state != BT_LISTEN)
+			goto release;
+
 		sk = sco_sock_alloc(sock_net(parent), NULL,
 				    BTPROTO_SCO, GFP_ATOMIC, 0);
-		if (!sk) {
-			release_sock(parent);
-			sco_conn_unlock(conn);
-			return;
-		}
+		if (!sk)
+			goto release;
 
 		sco_sock_init(sk, parent);
 
@@ -1417,9 +1441,10 @@ static void sco_conn_ready(struct sco_conn *conn)
 		/* Wake up parent */
 		parent->sk_data_ready(parent);
 
-		release_sock(parent);
-
+release:
 		sco_conn_unlock(conn);
+		release_sock(parent);
+		sock_put(parent);
 	}
 }