[PATCH net v2 2/3] net: nixge: avoid overwriting buffer descriptor

From: Zhang Changzhong
Date: Tue Nov 15 2022 - 09:51:45 EST


The check on the number of available BDs is incorrect because BDs are
required not only for frags but also for skb. This may result in
overwriting BD that is still in use.

Fixes: 492caffa8a1a ("net: ethernet: nixge: Add support for National Instruments XGE netdev")
Signed-off-by: Zhang Changzhong <zhangchangzhong@xxxxxxxxxx>
---
drivers/net/ethernet/ni/nixge.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ni/nixge.c b/drivers/net/ethernet/ni/nixge.c
index d8cd520..91b7ebc 100644
--- a/drivers/net/ethernet/ni/nixge.c
+++ b/drivers/net/ethernet/ni/nixge.c
@@ -518,7 +518,7 @@ static netdev_tx_t nixge_start_xmit(struct sk_buff *skb,
cur_p = &priv->tx_bd_v[priv->tx_bd_tail];
tx_skb = &priv->tx_skb[priv->tx_bd_tail];

- if (nixge_check_tx_bd_space(priv, num_frag)) {
+ if (nixge_check_tx_bd_space(priv, num_frag + 1)) {
if (!netif_queue_stopped(ndev))
netif_stop_queue(ndev);
return NETDEV_TX_OK;
--
2.9.5