[PATCH] net: ethernet: mtk_eth_soc: fix off by one check of ARRAY_SIZE

From: Tom Rix
Date: Sat Jul 16 2022 - 17:47:09 EST


In mtk_wed_tx_ring_setup(.., int idx, ..), idx is used as an index here
struct mtk_wed_ring *ring = &dev->tx_ring[idx];

The bounds of idx are checked here
BUG_ON(idx > ARRAY_SIZE(dev->tx_ring));

If idx is the size of the array, it will pass this check and overflow.
So change the check to >= .

Fixes: 804775dfc288 ("net: ethernet: mtk_eth_soc: add support for Wireless Ethernet Dispatch (WED)")
Signed-off-by: Tom Rix <trix@xxxxxxxxxx>
---
drivers/net/ethernet/mediatek/mtk_wed.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_wed.c b/drivers/net/ethernet/mediatek/mtk_wed.c
index 8f0cd3196aac..29be2fcafea3 100644
--- a/drivers/net/ethernet/mediatek/mtk_wed.c
+++ b/drivers/net/ethernet/mediatek/mtk_wed.c
@@ -651,7 +651,7 @@ mtk_wed_tx_ring_setup(struct mtk_wed_device *dev, int idx, void __iomem *regs)
* WDMA RX.
*/

- BUG_ON(idx > ARRAY_SIZE(dev->tx_ring));
+ BUG_ON(idx >= ARRAY_SIZE(dev->tx_ring));

if (mtk_wed_ring_alloc(dev, ring, MTK_WED_TX_RING_SIZE))
return -ENOMEM;
--
2.27.0