mt76: add size check for additional rx fragments

So far the code only validates the buffer size of the first skb.
Extend this check to cover additional fragments as well, in case the size
is corrupted during a DMA reset.
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/dma.c

@@ -430,6 +430,14 @@ mt76_dma_rx_process(struct mt76_dev *dev, struct mt76_queue *q, int budget)
 		if (!data)
 			break;
 
+		if (q->buf_size < len + q->buf_offset) {
+			dev_kfree_skb(q->rx_head);
+			q->rx_head = NULL;
+
+			skb_free_frag(data);
+			continue;
+		}
+
 		if (q->rx_head) {
 			mt76_add_fragment(dev, q, data, len, more);
 			continue;