[PATCH 4/6] xen-netfront: add range check for Tx response id

[Marek Marczykowski-GÃrecki]

Tx response ID is fetched from shared page, so make sure it is sane
before using it as an array index.

CC: stable@xxxxxxxxxxxxxxx
Signed-off-by: Marek Marczykowski-GÃrecki <marmarek@xxxxxxxxxxxxxxxxxxxxxx>
---
 drivers/net/xen-netfront.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 934b8a4..55c9b25 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -394,6 +394,7 @@ static void xennet_tx_buf_gc(struct netfront_queue *queue)
 				continue;
 
 			id  = txrsp.id;
+			BUG_ON(id >= NET_TX_RING_SIZE);
 			skb = queue->tx_skbs[id].skb;
 			if (unlikely(gnttab_query_foreign_access(
 				queue->grant_tx_ref[id]) != 0)) {
-- 
git-series 0.9.1