mt76: mt7615: Use after free in mt7615_mcu_set_bcn()

We dereference "skb" when we assign:

	req.pkt_len = cpu_to_le16(MT_TXD_SIZE + skb->len);
                                                ^^^^^^^^
So this patch just moves the dev_kfree_skb() down a bit to avoid the
use after free.

Fixes: 04b8e65922f6 ("mt76: add mac80211 driver for MT7615 PCIe-based chipsets")
Signed-off-by: Dan Carpenter <[email protected]>
Acked-by: Lorenzo Bianconi <[email protected]>
Signed-off-by: Felix Fietkau <[email protected]>
This commit is contained in:
Dan Carpenter
2019-05-11 15:57:46 +02:00
committed by Felix Fietkau
parent b4ceb9f7c7
commit d00dc95240
+1 -1
View File
@@ -1270,7 +1270,6 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, struct ieee80211_vif *vif,
mt7615_mac_write_txwi(dev, (__le32 *)(req.pkt), skb, wcid, NULL,
0, NULL);
memcpy(req.pkt + MT_TXD_SIZE, skb->data, skb->len);
dev_kfree_skb(skb);
req.omac_idx = mvif->omac_idx;
req.enable = en;
@@ -1281,6 +1280,7 @@ int mt7615_mcu_set_bcn(struct mt7615_dev *dev, struct ieee80211_vif *vif,
req.pkt_len = cpu_to_le16(MT_TXD_SIZE + skb->len);
req.tim_ie_pos = cpu_to_le16(MT_TXD_SIZE + tim_off);
dev_kfree_skb(skb);
skb = mt7615_mcu_msg_alloc(&req, sizeof(req));
return mt7615_mcu_msg_send(dev, skb, MCU_EXT_CMD_BCN_OFFLOAD,