[PATCH 5.11 060/601] mt76: fix potential DMA mapping leak

Greg Kroah-Hartman
2021-05-12T16:53:25Z

From: Felix Fietkau <nbd@nbd.name>

commit b4403cee6400c5f679e9c4a82b91d61aa961eccf upstream.

With buf uninitialized in mt76_dma_tx_queue_skb_raw, its field skip_unmap
could potentially inherit a non-zero value from stack garbage.
If this happens, it will cause DMA mappings for MCU command frames to not be
unmapped after completion

Fixes: 27d5c528a7ca ("mt76: fix double DMA unmap of the first buffer on 7615/7915")
Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/wireless/mediatek/mt76/dma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -309,7 +309,7 @@ static int
mt76_dma_tx_queue_skb_raw(struct mt76_dev *dev, struct mt76_queue *q,
struct sk_buff *skb, u32 tx_info)
{
- struct mt76_queue_buf buf;
+ struct mt76_queue_buf buf = {};
dma_addr_t addr;

if (q->queued + 1 >= q->ndesc - 1)