sh_eth: Fix crash or memory leak when resizing rings on device that is down
authorBen Hutchings <ben.hutchings@codethink.co.uk>
Thu, 22 Jan 2015 12:41:34 +0000 (12:41 +0000)
committerDavid S. Miller <davem@davemloft.net>
Tue, 27 Jan 2015 00:13:15 +0000 (16:13 -0800)
If the device is down then no packet buffers should be allocated.
We also must not touch its registers as it may be powered off.

Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
drivers/net/ethernet/renesas/sh_eth.c

index fa8a7b775b4ac42180cd64f71476d7d1349369e3..7facda1328f8bd35f6b688e0f251182ecaac2fd5 100644 (file)
@@ -1976,29 +1976,31 @@ static int sh_eth_set_ringparam(struct net_device *ndev,
                sh_eth_write(ndev, 0, EDTRR);
                sh_eth_write(ndev, 0, EDRRR);
                synchronize_irq(ndev->irq);
-       }
 
-       /* Free all the skbuffs in the Rx queue. */
-       sh_eth_ring_free(ndev);
-       /* Free DMA buffer */
-       sh_eth_free_dma_buffer(mdp);
+               /* Free all the skbuffs in the Rx queue. */
+               sh_eth_ring_free(ndev);
+               /* Free DMA buffer */
+               sh_eth_free_dma_buffer(mdp);
+       }
 
        /* Set new parameters */
        mdp->num_rx_ring = ring->rx_pending;
        mdp->num_tx_ring = ring->tx_pending;
 
-       ret = sh_eth_ring_init(ndev);
-       if (ret < 0) {
-               netdev_err(ndev, "%s: sh_eth_ring_init failed.\n", __func__);
-               return ret;
-       }
-       ret = sh_eth_dev_init(ndev, false);
-       if (ret < 0) {
-               netdev_err(ndev, "%s: sh_eth_dev_init failed.\n", __func__);
-               return ret;
-       }
-
        if (netif_running(ndev)) {
+               ret = sh_eth_ring_init(ndev);
+               if (ret < 0) {
+                       netdev_err(ndev, "%s: sh_eth_ring_init failed.\n",
+                                  __func__);
+                       return ret;
+               }
+               ret = sh_eth_dev_init(ndev, false);
+               if (ret < 0) {
+                       netdev_err(ndev, "%s: sh_eth_dev_init failed.\n",
+                                  __func__);
+                       return ret;
+               }
+
                sh_eth_write(ndev, mdp->cd->eesipr_value, EESIPR);
                /* Setting the Rx mode will start the Rx process. */
                sh_eth_write(ndev, EDRRR_R, EDRRR);