[v2] can: sja1000: plx_pci: fix error handling path in plx_pci_add_card()

[PATCH v2] can: sja1000: plx_pci: fix error handling path in plx_pci_add_card()

Posted by Zhang Changzhong 2 years, 9 months ago

If pci_iomap() or register_sja1000dev() fails, netdev will not be
registered, but plx_pci_del_card() still deregisters the netdev.

To avoid this, let's free the netdev and clear card->net_dev[i] before
calling plx_pci_del_card(). In addition, add the missing pci_iounmap()
when the channel does not exist.

Compile tested only.

Fixes: 951f2f960e5b ("drivers/net/can/sja1000/plx_pci.c: eliminate double free")
Fixes: 24c4a3b29255 ("can: add support for CAN interface cards based on the PLX90xx PCI bridge")
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
---
v1->v2: switch to goto style fix.

 drivers/net/can/sja1000/plx_pci.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/net/can/sja1000/plx_pci.c b/drivers/net/can/sja1000/plx_pci.c
index 5de1ebb..134a8cb 100644
--- a/drivers/net/can/sja1000/plx_pci.c
+++ b/drivers/net/can/sja1000/plx_pci.c
@@ -678,7 +678,7 @@ static int plx_pci_add_card(struct pci_dev *pdev,
 		if (!addr) {
 			err = -ENOMEM;
 			dev_err(&pdev->dev, "Failed to remap BAR%d\n", cm->bar);
-			goto failure_cleanup;
+			goto failure_free_dev;
 		}
 
 		priv->reg_base = addr + cm->offset;
@@ -699,7 +699,7 @@ static int plx_pci_add_card(struct pci_dev *pdev,
 			if (err) {
 				dev_err(&pdev->dev, "Registering device failed "
 					"(err=%d)\n", err);
-				goto failure_cleanup;
+				goto failure_iounmap;
 			}
 
 			card->channels++;
@@ -710,6 +710,7 @@ static int plx_pci_add_card(struct pci_dev *pdev,
 		} else {
 			dev_err(&pdev->dev, "Channel #%d not detected\n",
 				i + 1);
+			pci_iounmap(pdev, priv->reg_base);
 			free_sja1000dev(dev);
 			card->net_dev[i] = NULL;
 		}
@@ -738,6 +739,11 @@ static int plx_pci_add_card(struct pci_dev *pdev,
 	}
 	return 0;
 
+failure_iounmap:
+	pci_iounmap(pdev, priv->reg_base);
+failure_free_dev:
+	free_sja1000dev(dev);
+	card->net_dev[i] = NULL;
 failure_cleanup:
 	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);
 
-- 
2.9.5

Re: [PATCH v2] can: sja1000: plx_pci: fix error handling path in plx_pci_add_card()

Posted by Marc Kleine-Budde 2 years, 9 months ago

On 25.11.2022 21:46:14, Zhang Changzhong wrote:
> If pci_iomap() or register_sja1000dev() fails, netdev will not be
> registered, but plx_pci_del_card() still deregisters the netdev.
> 
> To avoid this, let's free the netdev and clear card->net_dev[i] before
> calling plx_pci_del_card(). In addition, add the missing pci_iounmap()
> when the channel does not exist.
> 
> Compile tested only.
> 
> Fixes: 951f2f960e5b ("drivers/net/can/sja1000/plx_pci.c: eliminate double free")
> Fixes: 24c4a3b29255 ("can: add support for CAN interface cards based on the PLX90xx PCI bridge")
> Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>
> ---
> v1->v2: switch to goto style fix.
> 
>  drivers/net/can/sja1000/plx_pci.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/can/sja1000/plx_pci.c b/drivers/net/can/sja1000/plx_pci.c
> index 5de1ebb..134a8cb 100644
> --- a/drivers/net/can/sja1000/plx_pci.c
> +++ b/drivers/net/can/sja1000/plx_pci.c
> @@ -678,7 +678,7 @@ static int plx_pci_add_card(struct pci_dev *pdev,
>  		if (!addr) {
>  			err = -ENOMEM;
>  			dev_err(&pdev->dev, "Failed to remap BAR%d\n", cm->bar);
> -			goto failure_cleanup;
> +			goto failure_free_dev;
>  		}
>  
>  		priv->reg_base = addr + cm->offset;
                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> @@ -699,7 +699,7 @@ static int plx_pci_add_card(struct pci_dev *pdev,
>  			if (err) {
>  				dev_err(&pdev->dev, "Registering device failed "
>  					"(err=%d)\n", err);
> -				goto failure_cleanup;
> +				goto failure_iounmap;
>  			}
>  
>  			card->channels++;
> @@ -710,6 +710,7 @@ static int plx_pci_add_card(struct pci_dev *pdev,
>  		} else {
>  			dev_err(&pdev->dev, "Channel #%d not detected\n",
>  				i + 1);
> +			pci_iounmap(pdev, priv->reg_base);
>  			free_sja1000dev(dev);
>  			card->net_dev[i] = NULL;
>  		}
> @@ -738,6 +739,11 @@ static int plx_pci_add_card(struct pci_dev *pdev,
>  	}
>  	return 0;
>  
> +failure_iounmap:
> +	pci_iounmap(pdev, priv->reg_base);
                          ^^^^^^^^^^^^^^

reg_base it not that what has been mapped, but with an offset.

> +failure_free_dev:
> +	free_sja1000dev(dev);
> +	card->net_dev[i] = NULL;
>  failure_cleanup:
>  	dev_err(&pdev->dev, "Error: %d. Cleaning Up.\n", err);

Marc

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