Subject: Re: [PATCH] arcnet: com20020-pci: Add check devm_kasprintf() returned value

From: Simon Horman <[email-masked]>
Date: Mon, 30 Sep 2024 16:21:49 +0100

On Sun, Sep 29, 2024 at 10:37:21AM +0800, Charles Han wrote:
> devm_kasprintf() can return a NULL pointer on failure but this
> returned value in com20020pci_probe() is not checked.
> 
> Fixes: 8890624a4e8c ("arcnet: com20020-pci: add led trigger support")
> Signed-off-by: Charles Han <[email-masked]>

Hi Charles,

As a fix for Networking code this looks like it should be targeted
at the 'net' tree. Please do that by using 'net' in the subject like this:

        Subject: [PATCH net v2] ...

Link: https://docs.kernel.org/process/maintainer-netdev.html

> ---
>  drivers/net/arcnet/com20020-pci.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/net/arcnet/com20020-pci.c b/drivers/net/arcnet/com20020-pci.c
> index c5e571ec94c9..6639ee11a7f8 100644
> --- a/drivers/net/arcnet/com20020-pci.c
> +++ b/drivers/net/arcnet/com20020-pci.c
> @@ -254,6 +254,8 @@ static int com20020pci_probe(struct pci_dev *pdev,
>  			card->tx_led.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
>  							"pci:green:tx:%d-%d",
>  							dev->dev_id, i);
> +			if (!card->tx_led.default_trigger || !card->tx_led.name)
> +				return -ENOMEM;

Looking at the rest of this function, I think the
correct unwind procedure is as follows (completely untested!):

			if (!card->tx_led.default_trigger ||
			    !card->tx_led.name) {
				ret = -ENOMEM;
				goto err_free_arcdev;
			}

>  
>  			card->tx_led.dev = &dev->dev;
>  			card->recon_led.brightness_set = led_recon_set;
> @@ -263,6 +265,9 @@ static int com20020pci_probe(struct pci_dev *pdev,
>  			card->recon_led.name = devm_kasprintf(&pdev->dev, GFP_KERNEL,
>  							"pci:red:recon:%d-%d",
>  							dev->dev_id, i);
> +			if (!card->recon_led.default_trigger || !card->recon_led.name)

Please line-wrap the line above so that it is <= 80 columns wide,
as is still preferred by Networking code. Checkpatch will flag
this when used with the --max-line-length=80 command line option.

> +				return -ENOMEM;
> +
>  			card->recon_led.dev = &dev->dev;
>  
>  			ret = devm_led_classdev_register(&pdev->dev, &card->tx_led);

-- 
pw-bot: changes-requested