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 <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mediatek/mtk_ppe.c b/drivers/net/ethernet/mediatek/mtk_ppe.c
index 282a1f34a88a7ff2d8ac51f7a18432567dfd1e6a..683f89f8e3b2e2194e8df39d0c7f9981f870a17c 100644 (file)
--- 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 *ppe, struct sk_buff *skb, u16 hash)
        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 *ppe, struct sk_buff *skb, u16 hash)
        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))