From 6c7fce6fa86a110d6455662d823c4e09f8f7be4a Mon Sep 17 00:00:00 2001 From: Sean Wang Date: Sat, 22 Jul 2017 20:45:55 +0800 Subject: [PATCH] net: ethernet: mediatek: avoid potential invalid memory access Potential dangerous invalid memory might be accessed if invalid mac value reflected from the forward port field in rxd4 caused by possible potential hardware defects. So added a simple sanity checker to avoid the kind of situation happening. Signed-off-by: Sean Wang Acked-by: John Crispin Signed-off-by: David S. Miller --- drivers/net/ethernet/mediatek/mtk_eth_soc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c index b3d0c2e6347a..3e3232fd7c05 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -947,6 +947,10 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget, RX_DMA_FPORT_MASK; mac--; + if (unlikely(mac < 0 || mac >= MTK_MAC_COUNT || + !eth->netdev[mac])) + goto release_desc; + netdev = eth->netdev[mac]; if (unlikely(test_bit(MTK_RESETTING, ð->state))) -- 2.20.1