NFC: digital: Ensure no NAD byte in DEP_REQ and DEP_RES frames

According to chapter 14 of the NFC-DEP Digital
Protocol Spec., the NAD byte should never be
present in DEP_REQ or DEP_RES frames.  However,
this is not enforced so add that enforcement code.

Reviewed-by: Thierry Escande <thierry.escande@linux.intel.com>
Tested-by: Thierry Escande <thierry.escande@linux.intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/net/nfc/digital_dep.c b/net/nfc/digital_dep.c
index 7d1c794556c3..d5e669b0dedf 100644
--- a/net/nfc/digital_dep.c
+++ b/net/nfc/digital_dep.c
@@ -420,6 +420,11 @@ static void digital_in_recv_dep_res(struct nfc_digital_dev *ddev, void *arg,
                 goto error;
         }
 
+        if (DIGITAL_NFC_DEP_NAD_BIT_SET(pfb)) {
+                rc = -EIO;
+                goto exit;
+        }
+
         if (size > resp->len) {
                 rc = -EIO;
                 goto error;
@@ -572,6 +577,11 @@ static void digital_tg_recv_dep_req(struct nfc_digital_dev *ddev, void *arg,
                 goto exit;
         }
 
+        if (DIGITAL_NFC_DEP_NAD_BIT_SET(pfb)) {
+                rc = -EIO;
+                goto exit;
+        }
+
         if (size > resp->len) {
                 rc = -EIO;
                 goto exit;