From 0fa4d83215b44a012a6c2e53deacbe2735253cd1 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 b3d0c2e6347a6..3e3232fd7c050 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))) -- 2.39.5