mt76: fix potential DMA mapping leak

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>

diff --git a/drivers/net/wireless/mediatek/mt76/dma.c b/drivers/net/wireless/mediatek/mt76/dma.c
index 665a03e..0fdfead 100644 (file)
--- a/drivers/net/wireless/mediatek/mt76/dma.c
+++ b/drivers/net/wireless/mediatek/mt76/dma.c
@@ -318,7 +318,7 @@ mt76_dma_tx_queue_skb_raw(struct mt76_dev *dev, enum mt76_txq_id qid,
                          struct sk_buff *skb, u32 tx_info)
 {
        struct mt76_queue *q = dev->q_tx[qid];
-       struct mt76_queue_buf buf;
+       struct mt76_queue_buf buf = {};
        dma_addr_t addr;
 
        if (q->queued + 1 >= q->ndesc - 1)