[PATCH net 2/2] ibmveth: fix TX LTB and filter unwind on open-fail

[Mingming Cao <mmc@linux.ibm.com>]

out_free_buffer_pools reuses open()'s loop index for the TX LTB
walk. After the pool unwind i is -1, so the TX buffers allocated
earlier are leaked. request_irq() failure has the same leak.

The TX-fail goto on that walk also skips dma_unmap of the filter
list (pre-existing since the LTB was added). Rewrite the TX walk
to real_num_tx_queues with a pointer check, and unmap the filter
list before those frees.

Fixes: d926793c1de9 ("ibmveth: Implement multi queue on xmit")
Cc: stable@vger.kernel.org
Signed-off-by: Mingming Cao <mmc@linux.ibm.com>
---
 drivers/net/ethernet/ibm/ibmveth.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index 3e44f6b714d4..abebdb1fc262 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -553,10 +553,15 @@ static int ibmveth_rxq_harvest_buffer(struct ibmveth_adapter *adapter,
 
 static void ibmveth_free_tx_ltb(struct ibmveth_adapter *adapter, int idx)
 {
+	void *ptr = adapter->tx_ltb_ptr[idx];
+
+	if (!ptr)
+		return;
+
+	adapter->tx_ltb_ptr[idx] = NULL;
 	dma_unmap_single(&adapter->vdev->dev, adapter->tx_ltb_dma[idx],
 			 adapter->tx_ltb_size, DMA_TO_DEVICE);
-	kfree(adapter->tx_ltb_ptr[idx]);
-	adapter->tx_ltb_ptr[idx] = NULL;
+	kfree(ptr);
 }
 
 static int ibmveth_allocate_tx_ltb(struct ibmveth_adapter *adapter, int idx)
@@ -667,7 +672,7 @@ static int ibmveth_open(struct net_device *netdev)
 
 	for (i = 0; i < netdev->real_num_tx_queues; i++) {
 		if (ibmveth_allocate_tx_ltb(adapter, i))
-			goto out_free_tx_ltb;
+			goto out_unmap_filter_list;
 	}
 
 	adapter->rx_queue.index = 0;
@@ -745,10 +750,8 @@ static int ibmveth_open(struct net_device *netdev)
 	dma_unmap_single(dev, adapter->filter_list_dma, 4096,
 			 DMA_BIDIRECTIONAL);
 
-out_free_tx_ltb:
-	while (--i >= 0) {
+	for (i = netdev->real_num_tx_queues - 1; i >= 0; i--)
 		ibmveth_free_tx_ltb(adapter, i);
-	}
 
 out_unmap_buffer_list:
 	dma_unmap_single(dev, adapter->buffer_list_dma, 4096,
-- 
2.50.1 (Apple Git-155)