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 609f92283d1b74d118eb00d0fcedd6ece105e844..321889ee2107863351e9b008371d0689c9a1338b 100644 (file)
--- a/net/nfc/nci/hci.c
+++ b/net/nfc/nci/hci.c
@@ -146,18 +146,18 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
        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 @@ static int nci_hci_send_data(struct nci_dev *ndev, u8 pipe,
                        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);