net: ethernet: mtk_eth_soc: out of bounds read in mtk_hwlro_get_fdir_entry()

[ Upstream commit e7e7104e2d5ddf3806a28695670f21bef471f1e1 ]

The "fsp->location" variable comes from user via ethtool_get_rxnfc().
Check that it is valid to prevent an out of bounds read.

Fixes: 7aab747e5563 ("net: ethernet: mediatek: add ethtool functions to configure RX flows of HW LRO")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index ee1fd47..d2d7160 100644 (file)
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1991,6 +1991,9 @@ static int mtk_hwlro_get_fdir_entry(struct net_device *dev,
        struct ethtool_rx_flow_spec *fsp =
                (struct ethtool_rx_flow_spec *)&cmd->fs;
 
+       if (fsp->location >= ARRAY_SIZE(mac->hwlro_ip))
+               return -EINVAL;
+
        /* only tcp dst ipv4 is meaningful, others are meaningless */
        fsp->flow_type = TCP_V4_FLOW;
        fsp->h_u.tcp_ip4_spec.ip4dst = ntohl(mac->hwlro_ip[fsp->location]);