ethoc: fix null dereference in ethoc_probe

Dan reported the patch 0baa080c75: "ethoc: use system memory
as buffer" introduced a potential null dereference.

  1060  free:
  1061          if (priv->dma_alloc)
                    ^^^^^^^^^^^^^^^
	priv can be null here.

He also suggested that the error handling is not complete.

This patch fixes the null priv issue and improves resources
releasing in ethoc_probe() and ethoc_remove().

Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Thomas Chou 2010-05-23 16:44:02 +00:00 committed by David S. Miller
parent 253683bbfb
commit ee02a4ef40

View File

@ -174,6 +174,7 @@ MODULE_PARM_DESC(buffer_size, "DMA buffer allocation size");
* @iobase: pointer to I/O memory region
* @membase: pointer to buffer memory region
* @dma_alloc: dma allocated buffer size
* @io_region_size: I/O memory region size
* @num_tx: number of send buffers
* @cur_tx: last send buffer written
* @dty_tx: last buffer actually sent
@ -193,6 +194,7 @@ struct ethoc {
void __iomem *iobase;
void __iomem *membase;
int dma_alloc;
resource_size_t io_region_size;
unsigned int num_tx;
unsigned int cur_tx;
@ -943,6 +945,7 @@ static int ethoc_probe(struct platform_device *pdev)
priv = netdev_priv(netdev);
priv->netdev = netdev;
priv->dma_alloc = 0;
priv->io_region_size = mmio->end - mmio->start + 1;
priv->iobase = devm_ioremap_nocache(&pdev->dev, netdev->base_addr,
resource_size(mmio));
@ -1047,20 +1050,34 @@ static int ethoc_probe(struct platform_device *pdev)
ret = register_netdev(netdev);
if (ret < 0) {
dev_err(&netdev->dev, "failed to register interface\n");
goto error;
goto error2;
}
goto out;
error2:
netif_napi_del(&priv->napi);
error:
mdiobus_unregister(priv->mdio);
free_mdio:
kfree(priv->mdio->irq);
mdiobus_free(priv->mdio);
free:
if (priv->dma_alloc)
dma_free_coherent(NULL, priv->dma_alloc, priv->membase,
netdev->mem_start);
if (priv) {
if (priv->dma_alloc)
dma_free_coherent(NULL, priv->dma_alloc, priv->membase,
netdev->mem_start);
else if (priv->membase)
devm_iounmap(&pdev->dev, priv->membase);
if (priv->iobase)
devm_iounmap(&pdev->dev, priv->iobase);
}
if (mem)
devm_release_mem_region(&pdev->dev, mem->start,
mem->end - mem->start + 1);
if (mmio)
devm_release_mem_region(&pdev->dev, mmio->start,
mmio->end - mmio->start + 1);
free_netdev(netdev);
out:
return ret;
@ -1078,6 +1095,7 @@ static int ethoc_remove(struct platform_device *pdev)
platform_set_drvdata(pdev, NULL);
if (netdev) {
netif_napi_del(&priv->napi);
phy_disconnect(priv->phy);
priv->phy = NULL;
@ -1089,6 +1107,14 @@ static int ethoc_remove(struct platform_device *pdev)
if (priv->dma_alloc)
dma_free_coherent(NULL, priv->dma_alloc, priv->membase,
netdev->mem_start);
else {
devm_iounmap(&pdev->dev, priv->membase);
devm_release_mem_region(&pdev->dev, netdev->mem_start,
netdev->mem_end - netdev->mem_start + 1);
}
devm_iounmap(&pdev->dev, priv->iobase);
devm_release_mem_region(&pdev->dev, netdev->base_addr,
priv->io_region_size);
unregister_netdev(netdev);
free_netdev(netdev);
}