From: Felix Fietkau <nbd@xxxxxxxx> [ Upstream commit 93eaec7625f13cffb593b471405b017c7e64d4ee ] Fixes a theoretical issue where it could potentially overwrite an existing descriptor entry (and leaking its skb) Signed-off-by: Felix Fietkau <nbd@xxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/net/wireless/mediatek/mt76/dma.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c index 6249a46c19762..026d996612fbe 100644 --- a/drivers/net/wireless/mediatek/mt76/dma.c +++ b/drivers/net/wireless/mediatek/mt76/dma.c @@ -261,10 +261,13 @@ mt76_dma_tx_queue_skb_raw(struct mt76_dev *dev, enum mt76_txq_id qid, struct mt76_queue_buf buf; dma_addr_t addr; + if (q->queued + 1 >= q->ndesc - 1) + goto error; + addr = dma_map_single(dev->dev, skb->data, skb->len, DMA_TO_DEVICE); if (unlikely(dma_mapping_error(dev->dev, addr))) - return -ENOMEM; + goto error; buf.addr = addr; buf.len = skb->len; @@ -275,6 +278,10 @@ mt76_dma_tx_queue_skb_raw(struct mt76_dev *dev, enum mt76_txq_id qid, spin_unlock_bh(&q->lock); return 0; + +error: + dev_kfree_skb(skb); + return -ENOMEM; } static int -- 2.20.1
