nfc: st-nci: Free data with irrelevant NDLC PCB_SYNC value

PCB_SYNC different than PCB_TYPE_SUPERVISOR or PCB_TYPE_DATAFRAME
should be discarded.

Irrelevant data may be forwarded up to the ndlc state machine by
phys like spi to prevent missing potential data during "write"
transactions.

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/drivers/nfc/st-nci/ndlc.c b/drivers/nfc/st-nci/ndlc.c
index bb08b16..4f51649 100644 (file)
--- a/drivers/nfc/st-nci/ndlc.c
+++ b/drivers/nfc/st-nci/ndlc.c
@@ -198,8 +198,10 @@ static void llt_ndlc_rcv_queue(struct llt_ndlc *ndlc)
                                kfree_skb(skb);
                                break;
                        }
-               } else {
+               } else if ((pcb & PCB_TYPE_MASK) == PCB_TYPE_DATAFRAME) {
                        nci_recv_frame(ndlc->ndev, skb);
+               } else {
+                       kfree_skb(skb);
                }
        }
 }