1 files changed, 34 insertions, 6 deletions

diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 5deb6c4f1e41..3de3e3c8e966 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -926,16 +926,39 @@ int l2cap_chan_check_security(struct l2cap_chan *chan, bool initiator)
 
 static int l2cap_get_ident(struct l2cap_conn *conn)
 {
+	u8 max;
+	int ident;
+
 	/* LE link does not support tools like l2ping so use the full range */
 	if (conn->hcon->type == LE_LINK)
-		return ida_alloc_range(&conn->tx_ida, 1, 255, GFP_ATOMIC);
-
+		max = 255;
 	/* Get next available identificator.
 	 *    1 - 128 are used by kernel.
 	 *  129 - 199 are reserved.
 	 *  200 - 254 are used by utilities like l2ping, etc.
 	 */
-	return ida_alloc_range(&conn->tx_ida, 1, 128, GFP_ATOMIC);
+	else
+		max = 128;
+
+	/* Allocate ident using min as last used + 1 (cyclic) */
+	ident = ida_alloc_range(&conn->tx_ida, READ_ONCE(conn->tx_ident) + 1,
+				max, GFP_ATOMIC);
+	/* Force min 1 to start over */
+	if (ident <= 0) {
+		ident = ida_alloc_range(&conn->tx_ida, 1, max, GFP_ATOMIC);
+		if (ident <= 0) {
+			/* If all idents are in use, log an error, this is
+			 * extremely unlikely to happen and would indicate a bug
+			 * in the code that idents are not being freed properly.
+			 */
+			BT_ERR("Unable to allocate ident: %d", ident);
+			return 0;
+		}
+	}
+
+	WRITE_ONCE(conn->tx_ident, ident);
+
+	return ident;
 }
 
 static void l2cap_send_acl(struct l2cap_conn *conn, struct sk_buff *skb,
@@ -5081,14 +5104,14 @@ static inline int l2cap_ecred_conn_req(struct l2cap_conn *conn,
 	cmd_len -= sizeof(*req);
 	num_scid = cmd_len / sizeof(u16);
 
-	/* Always respond with the same number of scids as in the request */
-	rsp_len = cmd_len;
-
 	if (num_scid > L2CAP_ECRED_MAX_CID) {
 		result = L2CAP_CR_LE_INVALID_PARAMS;
 		goto response;
 	}
 
+	/* Always respond with the same number of scids as in the request */
+	rsp_len = cmd_len;
+
 	mtu  = __le16_to_cpu(req->mtu);
 	mps  = __le16_to_cpu(req->mps);
 
@@ -6690,6 +6713,11 @@ static int l2cap_ecred_data_rcv(struct l2cap_chan *chan, struct sk_buff *skb)
 	if (!chan->sdu) {
 		u16 sdu_len;
 
+		if (!pskb_may_pull(skb, L2CAP_SDULEN_SIZE)) {
+			err = -EINVAL;
+			goto failed;
+		}
+
 		sdu_len = get_unaligned_le16(skb->data);
 		skb_pull(skb, L2CAP_SDULEN_SIZE);