qede: Fix out-of-bound fastpath memory access

Mintz, Yuval · davem330 · commit 087892d29b75 · 2016-10-29T20:51:46.000-04:00
Driver allocates a shadow array for transmitted SKBs with X entries;
That means valid indices are {0,...,X - 1}. [X == 8191]
Problem is the driver also uses X as a mask for a
producer/consumer in order to choose the right entry in the
array which allows access to entry X which is out of bounds.

To fix this, simply allocate X + 1 entries in the shadow array.

Signed-off-by: Yuval Mintz &lt;Yuval.Mintz@cavium.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -2940,7 +2940,7 @@ static int qede_alloc_mem_txq(struct qede_dev *edev, struct qede_tx_queue *txq)
 	txq->num_tx_buffers = edev->q_num_tx_buffers;
 
 	/* Allocate the parallel driver ring for Tx buffers */
-	size = sizeof(*txq->sw_tx_ring) * NUM_TX_BDS_MAX;
+	size = sizeof(*txq->sw_tx_ring) * TX_RING_SIZE;
 	txq->sw_tx_ring = kzalloc(size, GFP_KERNEL);
 	if (!txq->sw_tx_ring) {
 		DP_NOTICE(edev, "Tx buffers ring allocation failed\n");
@@ -2951,7 +2951,7 @@ static int qede_alloc_mem_txq(struct qede_dev *edev, struct qede_tx_queue *txq)
 					    QED_CHAIN_USE_TO_CONSUME_PRODUCE,
 					    QED_CHAIN_MODE_PBL,
 					    QED_CHAIN_CNT_TYPE_U16,
-					    NUM_TX_BDS_MAX,
+					    TX_RING_SIZE,
 					    sizeof(*p_virt), &txq->tx_pbl);
 	if (rc)
 		goto err;
