Re: [PATCH] media: airspy: fix memory leak in airspy probe

[Tommaso Merciai]

Hi Dongliang,

On Thu, Aug 11, 2022 at 12:57:00PM +0800, Dongliang Mu wrote:
> From: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
> 
> The commit ca9dc8d06ab6 ("media: airspy: respect the DMA coherency
>  rules") moves variable buf from stack to heap, however, it only frees
> buf in the error handling code, missing deallocation in the success
> path.
> 
> Fix this by freeing buf in the success path since this variable does not
> have any references in other code.
> 
> Fixes: ca9dc8d06ab6 ("media: airspy: respect the DMA coherency rules")
> Reported-by: syzbot+bb25f85e5aa482864dc0@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
> ---
>  drivers/media/usb/airspy/airspy.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/media/usb/airspy/airspy.c b/drivers/media/usb/airspy/airspy.c
> index 240a7cc56777..7b1c40132555 100644
> --- a/drivers/media/usb/airspy/airspy.c
> +++ b/drivers/media/usb/airspy/airspy.c
> @@ -1070,6 +1070,10 @@ static int airspy_probe(struct usb_interface *intf,
>  				ret);
>  		goto err_free_controls;
>  	}
> +
> +	/* Free buf if success*/
> +	kfree(buf);
> +

buf var is only used to print the fw version during the probe.
I think you are right we need to free this.

Reviewed-by: Tommaso Merciai <tommaso.merciai@xxxxxxxxxxxxxxxxxxx>

>  	dev_info(s->dev, "Registered as %s\n",
>  			video_device_node_name(&s->vdev));
>  	dev_notice(s->dev, "SDR API is still slightly experimental and functionality changes may follow\n");
> -- 
> 2.35.1
> 

Regards,
Tommaso

-- 
Tommaso Merciai
Embedded Linux Engineer
tommaso.merciai@xxxxxxxxxxxxxxxxxxxx
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