NFC: nci: Fix incorrect data chaining when sending data

When sending HCI data over NCI, cmd information should be
present only on the first packet.
Each packet shall be specifically allocated and sent to the
NCI layer.

Cc: stable@vger.kernel.org
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
diff --git a/net/nfc/nci/hci.c b/net/nfc/nci/hci.c
index 609f922..321889e 100644
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -146,18 +146,18 @@
 	if (!conn_info)
 		return -EPROTO;
 
-	skb = nci_skb_alloc(ndev, 2 + conn_info->max_pkt_payload_len +
+	i = 0;
+	skb = nci_skb_alloc(ndev, conn_info->max_pkt_payload_len +
 			    NCI_DATA_HDR_SIZE, GFP_KERNEL);
 	if (!skb)
 		return -ENOMEM;
 
-	skb_reserve(skb, 2 + NCI_DATA_HDR_SIZE);
+	skb_reserve(skb, NCI_DATA_HDR_SIZE + 2);
 	*skb_push(skb, 1) = data_type;
 
-	i = 0;
-	len = conn_info->max_pkt_payload_len;
-
 	do {
+		len = conn_info->max_pkt_payload_len;
+
 		/* If last packet add NCI_HFP_NO_CHAINING */
 		if (i + conn_info->max_pkt_payload_len -
 		    (skb->len + 1) >= data_len) {
@@ -177,9 +177,15 @@
 			return r;
 
 		i += len;
+
 		if (i < data_len) {
-			skb_trim(skb, 0);
-			skb_pull(skb, len);
+			skb = nci_skb_alloc(ndev,
+					    conn_info->max_pkt_payload_len +
+					    NCI_DATA_HDR_SIZE, GFP_KERNEL);
+			if (!skb)
+				return -ENOMEM;
+
+			skb_reserve(skb, NCI_DATA_HDR_SIZE + 1);
 		}
 	} while (i < data_len);