[PATCH 5.10 395/406] net: ethernet: mtk_eth_soc: fix possible NULL pointer dereference in mtk_hwlro_get_fdir_all()

Greg Kroah-Hartman
2023-09-17T19:43:56Z

From: Hangyu Hua <hbh25y@gmail.com>

[ Upstream commit e4c79810755f66c9a933ca810da2724133b1165a ]

rule_locs is allocated in ethtool_get_rxnfc and the size is determined by
rule_cnt from user space. So rule_cnt needs to be check before using
rule_locs to avoid NULL pointer dereference.

Fixes: 7aab747e5563 ("net: ethernet: mediatek: add ethtool functions to configure RX flows of HW LRO")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/mediatek/mtk_eth_soc.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index a8319295f1ab2..aa9e616cc1d59 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -2013,6 +2013,9 @@ static int mtk_hwlro_get_fdir_all(struct net_device *dev,
int i;

for (i = 0; i < MTK_MAX_LRO_IP_CNT; i++) {
+ if (cnt == cmd->rule_cnt)
+ return -EMSGSIZE;
+
if (mac->hwlro_ip[i]) {
rule_locs[cnt] = i;
cnt++;
--
2.40.1