From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> commit 9db1aec0c2d72a3b7b115ba56e8dbb5b46855333 upstream. 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 <dan.carpenter@xxxxxxxxxx> Acked-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx> Signed-off-by: Felix Fietkau <nbd@xxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/net/wireless/mediatek/mt76/mt7615/mcu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c @@ -1270,7 +1270,6 @@ int mt7615_mcu_set_bcn(struct mt7615_dev 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 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,