From 93eaec7625f13cffb593b471405b017c7e64d4ee Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Mon, 20 Jan 2020 12:08:30 +0100 Subject: [PATCH] mt76: fix handling full tx queues in mt76_dma_tx_queue_skb_raw Fixes a theoretical issue where it could potentially overwrite an existing descriptor entry (and leaking its skb) Signed-off-by: Felix Fietkau --- 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 e69329feed78..bcb11bb9aeeb 100644 --- a/drivers/net/wireless/mediatek/mt76/dma.c +++ b/drivers/net/wireless/mediatek/mt76/dma.c @@ -271,10 +271,13 @@ 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; @@ -285,6 +288,10 @@ 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 -- 2.11.0