From: Dan Carpenter Date: Tue, 12 Apr 2022 12:24:19 +0300 Subject: [PATCH] net: ethernet: mtk_eth_soc: use after free in __mtk_ppe_check_skb() The __mtk_foe_entry_clear() function frees "entry" so we have to use the _safe() version of hlist_for_each_entry() to prevent a use after free. Fixes: 33fc42de3327 ("net: ethernet: mtk_eth_soc: support creating mac address based offload entries") Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller --- --- a/drivers/net/ethernet/mediatek/mtk_ppe.c +++ b/drivers/net/ethernet/mediatek/mtk_ppe.c @@ -600,6 +600,7 @@ void __mtk_ppe_check_skb(struct mtk_ppe struct mtk_foe_entry *hwe = &ppe->foe_table[hash]; struct mtk_flow_entry *entry; struct mtk_foe_bridge key = {}; + struct hlist_node *n; struct ethhdr *eh; bool found = false; u8 *tag; @@ -609,7 +610,7 @@ void __mtk_ppe_check_skb(struct mtk_ppe if (FIELD_GET(MTK_FOE_IB1_STATE, hwe->ib1) == MTK_FOE_STATE_BIND) goto out; - hlist_for_each_entry(entry, head, list) { + hlist_for_each_entry_safe(entry, n, head, list) { if (entry->type == MTK_FLOW_TYPE_L2_SUBFLOW) { if (unlikely(FIELD_GET(MTK_FOE_IB1_STATE, hwe->ib1) == MTK_FOE_STATE_BIND))