gianfar: Reject out-of-range RX NFC locations

Currently the driver only uses location values to maintain an ordered
list of filters.  Make it reject location values >= MAX_FILER_IDX
passed to the ETHTOOL_SRXCLSRLINS command, consistent with the range
it reports for the ETHTOOL_GRXCLSRLALL command.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Sebastian Pöhn <sebastian.poehn@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/gianfar_ethtool.c b/drivers/net/ethernet/freescale/gianfar_ethtool.c
index 5890f4b..5a3b2e5 100644
--- a/drivers/net/ethernet/freescale/gianfar_ethtool.c
+++ b/drivers/net/ethernet/freescale/gianfar_ethtool.c
@@ -1692,8 +1692,9 @@
 		ret = gfar_set_hash_opts(priv, cmd);
 		break;
 	case ETHTOOL_SRXCLSRLINS:
-		if (cmd->fs.ring_cookie != RX_CLS_FLOW_DISC &&
-			cmd->fs.ring_cookie >= priv->num_rx_queues) {
+		if ((cmd->fs.ring_cookie != RX_CLS_FLOW_DISC &&
+		     cmd->fs.ring_cookie >= priv->num_rx_queues) ||
+		    cmd->fs.location >= MAX_FILER_IDX) {
 			ret = -EINVAL;
 			break;
 		}