Commit ee02a4ef authored by Thomas Chou's avatar Thomas Chou Committed by David S. Miller
Browse files

ethoc: fix null dereference in ethoc_probe 



Dan reported the patch 0baa080c: "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: default avatarDan Carpenter <error27@gmail.com>
Signed-off-by: default avatarThomas Chou <thomas@wytron.com.tw>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 253683bb

drivers/net/ethoc.c

+30 −4
Original line number Diff line number Diff line
@@ -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) {

		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);

	}

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