commit 2c9938e738a273ba315679781a9990c7d3b1831b
author Esben Haabendal <esben@geanix.com> Tue Apr 30 09:17:56 2019 +0200
committer David S. Miller <davem@davemloft.net> Wed May 01 14:33:30 2019 -0400
tree b7183204ab0089c1e0debdf53d3351345df5a0c7
parent a8c9bd3ba84084b6cca704d5b21ee0ba971b748b

net: ll_temac: Fix bug causing buffer descriptor overrun

As we are actually using a BD for both the skb and each frag contained in
it, the oldest TX BD would be overwritten when there was exactly one BD
less than needed.

Signed-off-by: Esben Haabendal <esben@geanix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/xilinx/ll_temac_main.c

diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
index 7e42746..6837565 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -743,7 +743,7 @@
 	start_p = lp->tx_bd_p + sizeof(*lp->tx_bd_v) * lp->tx_bd_tail;
 	cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
 
-	if (temac_check_tx_bd_space(lp, num_frag)) {
+	if (temac_check_tx_bd_space(lp, num_frag + 1)) {
 		if (!netif_queue_stopped(ndev))
 			netif_stop_queue(ndev);
 		return NETDEV_TX_BUSY;