Re: [PATCH] dmaengine: avoid non-constant format string

[Dave Jiang]

On 7/19/24 3:23 AM, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
> 
> Using an arbitrary string as a printf-style format can be a security
> problem if that string contains % characters, as the optionalal
> -Wformat-security flag points out:
> 
> drivers/dma/dmaengine.c: In function '__dma_async_device_channel_register':
> drivers/dma/dmaengine.c:1073:17: error: format not a string literal and no format arguments [-Werror=format-security]
>  1073 |                 dev_set_name(&chan->dev->device, name);
>       |                 ^~~~~~~~~~~~
> 
> Change this newly added instance to use "%s" as the format instead to
> pass the actual name.
> 
> Fixes: 10b8e0fd3f72 ("dmaengine: add channel device name to channel registration")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>

> ---
>  drivers/dma/dmaengine.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
> index c380a4dda77a..c1357d7f3dc6 100644
> --- a/drivers/dma/dmaengine.c
> +++ b/drivers/dma/dmaengine.c
> @@ -1070,7 +1070,7 @@ static int __dma_async_device_channel_register(struct dma_device *device,
>  	if (!name)
>  		dev_set_name(&chan->dev->device, "dma%dchan%d", device->dev_id, chan->chan_id);
>  	else
> -		dev_set_name(&chan->dev->device, name);
> +		dev_set_name(&chan->dev->device, "%s", name);
>  	rc = device_register(&chan->dev->device);
>  	if (rc)
>  		goto err_out_ida;