Merging upstream version 4.19.269.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 71 insertions, 13 deletions

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 65d20bdff..fd6cd47a6 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -63,6 +63,9 @@ static void l2cap_send_disconn_req(struct l2cap_chan *chan, int err);
 
 static void l2cap_tx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
 		     struct sk_buff_head *skbs, u8 event);
+static void l2cap_retrans_timeout(struct work_struct *work);
+static void l2cap_monitor_timeout(struct work_struct *work);
+static void l2cap_ack_timeout(struct work_struct *work);
 
 static inline u8 bdaddr_type(u8 link_type, u8 bdaddr_type)
 {
@@ -470,6 +473,9 @@ struct l2cap_chan *l2cap_chan_create(void)
 	write_unlock(&chan_list_lock);
 
 	INIT_DELAYED_WORK(&chan->chan_timer, l2cap_chan_timeout);
+	INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout);
+	INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout);
+	INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout);
 
 	chan->state = BT_OPEN;
 
@@ -1818,7 +1824,7 @@ static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
 		if (link_type == LE_LINK && c->src_type == BDADDR_BREDR)
 			continue;
 
-		if (c->psm == psm) {
+		if (c->chan_type != L2CAP_CHAN_FIXED && c->psm == psm) {
 			int src_match, dst_match;
 			int src_any, dst_any;
 
@@ -3154,10 +3160,6 @@ int l2cap_ertm_init(struct l2cap_chan *chan)
 	chan->rx_state = L2CAP_RX_STATE_RECV;
 	chan->tx_state = L2CAP_TX_STATE_XMIT;
 
-	INIT_DELAYED_WORK(&chan->retrans_timer, l2cap_retrans_timeout);
-	INIT_DELAYED_WORK(&chan->monitor_timer, l2cap_monitor_timeout);
-	INIT_DELAYED_WORK(&chan->ack_timer, l2cap_ack_timeout);
-
 	skb_queue_head_init(&chan->srej_q);
 
 	err = l2cap_seq_list_init(&chan->srej_list, chan->tx_win);
@@ -3549,7 +3551,8 @@ done:
 			l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC,
 					   sizeof(rfc), (unsigned long) &rfc, endptr - ptr);
 
-			if (test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
+			if (remote_efs &&
+			    test_bit(FLAG_EFS_ENABLE, &chan->flags)) {
 				chan->remote_id = efs.id;
 				chan->remote_stype = efs.stype;
 				chan->remote_msdu = le16_to_cpu(efs.msdu);
@@ -4047,6 +4050,12 @@ static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
 		}
 	}
 
+	chan = l2cap_chan_hold_unless_zero(chan);
+	if (!chan) {
+		err = -EBADSLT;
+		goto unlock;
+	}
+
 	err = 0;
 
 	l2cap_chan_lock(chan);
@@ -4076,6 +4085,7 @@ static int l2cap_connect_create_rsp(struct l2cap_conn *conn,
 	}
 
 	l2cap_chan_unlock(chan);
+	l2cap_chan_put(chan);
 
 unlock:
 	mutex_unlock(&conn->chan_lock);
@@ -5543,6 +5553,19 @@ static int l2cap_le_connect_req(struct l2cap_conn *conn,
 	BT_DBG("psm 0x%2.2x scid 0x%4.4x mtu %u mps %u", __le16_to_cpu(psm),
 	       scid, mtu, mps);
 
+	/* BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
+	 * page 1059:
+	 *
+	 * Valid range: 0x0001-0x00ff
+	 *
+	 * Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
+	 */
+	if (!psm || __le16_to_cpu(psm) > L2CAP_PSM_LE_DYN_END) {
+		result = L2CAP_CR_BAD_PSM;
+		chan = NULL;
+		goto response;
+	}
+
 	/* Check if we have socket listening on psm */
 	pchan = l2cap_global_chan_by_psm(BT_LISTEN, psm, &conn->hcon->src,
 					 &conn->hcon->dst, LE_LINK);
@@ -6246,6 +6269,7 @@ static int l2cap_rx_state_recv(struct l2cap_chan *chan,
 			       struct l2cap_ctrl *control,
 			       struct sk_buff *skb, u8 event)
 {
+	struct l2cap_ctrl local_control;
 	int err = 0;
 	bool skb_in_use = false;
 
@@ -6270,15 +6294,32 @@ static int l2cap_rx_state_recv(struct l2cap_chan *chan,
 			chan->buffer_seq = chan->expected_tx_seq;
 			skb_in_use = true;
 
+			/* l2cap_reassemble_sdu may free skb, hence invalidate
+			 * control, so make a copy in advance to use it after
+			 * l2cap_reassemble_sdu returns and to avoid the race
+			 * condition, for example:
+			 *
+			 * The current thread calls:
+			 *   l2cap_reassemble_sdu
+			 *     chan->ops->recv == l2cap_sock_recv_cb
+			 *       __sock_queue_rcv_skb
+			 * Another thread calls:
+			 *   bt_sock_recvmsg
+			 *     skb_recv_datagram
+			 *     skb_free_datagram
+			 * Then the current thread tries to access control, but
+			 * it was freed by skb_free_datagram.
+			 */
+			local_control = *control;
 			err = l2cap_reassemble_sdu(chan, skb, control);
 			if (err)
 				break;
 
-			if (control->final) {
+			if (local_control.final) {
 				if (!test_and_clear_bit(CONN_REJ_ACT,
 							&chan->conn_state)) {
-					control->final = 0;
-					l2cap_retransmit_all(chan, control);
+					local_control.final = 0;
+					l2cap_retransmit_all(chan, &local_control);
 					l2cap_ertm_send(chan);
 				}
 			}
@@ -6658,11 +6699,27 @@ static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
 static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
 			   struct sk_buff *skb)
 {
+	/* l2cap_reassemble_sdu may free skb, hence invalidate control, so store
+	 * the txseq field in advance to use it after l2cap_reassemble_sdu
+	 * returns and to avoid the race condition, for example:
+	 *
+	 * The current thread calls:
+	 *   l2cap_reassemble_sdu
+	 *     chan->ops->recv == l2cap_sock_recv_cb
+	 *       __sock_queue_rcv_skb
+	 * Another thread calls:
+	 *   bt_sock_recvmsg
+	 *     skb_recv_datagram
+	 *     skb_free_datagram
+	 * Then the current thread tries to access control, but it was freed by
+	 * skb_free_datagram.
+	 */
+	u16 txseq = control->txseq;
+
 	BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb,
 	       chan->rx_state);
 
-	if (l2cap_classify_txseq(chan, control->txseq) ==
-	    L2CAP_TXSEQ_EXPECTED) {
+	if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) {
 		l2cap_pass_to_tx(chan, control);
 
 		BT_DBG("buffer_seq %d->%d", chan->buffer_seq,
@@ -6685,8 +6742,8 @@ static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control,
 		}
 	}
 
-	chan->last_acked_seq = control->txseq;
-	chan->expected_tx_seq = __next_seq(chan, control->txseq);
+	chan->last_acked_seq = txseq;
+	chan->expected_tx_seq = __next_seq(chan, txseq);
 
 	return 0;
 }
@@ -6924,6 +6981,7 @@ static void l2cap_data_channel(struct l2cap_conn *conn, u16 cid,
 				return;
 			}
 
+			l2cap_chan_hold(chan);
 			l2cap_chan_lock(chan);
 		} else {
 			BT_DBG("unknown cid 0x%4.4x", cid);