[PATCH net] net: ethernet: mtk_eth_soc: check max allowed hash in mtk_ppe_check_skb

[Lorenzo Bianconi]

Even if max hash configured in hw in mtk_ppe_hash_entry is
MTK_PPE_ENTRIES - 1, check theoretical OOB accesses in
mtk_ppe_check_skb routine

Fixes: c4f033d9e03e9 ("net: ethernet: mtk_eth_soc: rework hardware flow table management")
Signed-off-by: Lorenzo Bianconi <lorenzo at kernel.org>
---
 drivers/net/ethernet/mediatek/mtk_ppe.h | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.h b/drivers/net/ethernet/mediatek/mtk_ppe.h
index 1f5cf1c9a947..69ffce04d630 100644
--- a/drivers/net/ethernet/mediatek/mtk_ppe.h
+++ b/drivers/net/ethernet/mediatek/mtk_ppe.h
@@ -293,6 +293,9 @@ mtk_ppe_check_skb(struct mtk_ppe *ppe, struct sk_buff *skb, u16 hash)
 	if (!ppe)
 		return;
 
+	if (hash > MTK_PPE_HASH_MASK)
+		return;
+
 	now = (u16)jiffies;
 	diff = now - ppe->foe_check_time[hash];
 	if (diff < HZ / 10)
-- 
2.37.3