Re: [PATCH] serial: imx: fix a possible NULL dereference

["Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>]

Hello,

On Thu, Nov 12, 2015 at 08:46:21AM +0100, LABBE Corentin wrote:
> of_match_device could return NULL, and so cause a NULL pointer
> dereference later.
> 
> Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>
> ---
>  drivers/tty/serial/imx.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
> index 016e4be..22e91f7 100644
> --- a/drivers/tty/serial/imx.c
> +++ b/drivers/tty/serial/imx.c
> @@ -1857,8 +1857,7 @@ static int serial_imx_probe_dt(struct imx_port *sport,
>  		struct platform_device *pdev)
>  {
>  	struct device_node *np = pdev->dev.of_node;
> -	const struct of_device_id *of_id =
> -			of_match_device(imx_uart_dt_ids, &pdev->dev);
> +	const struct of_device_id *of_id;
>  	int ret;
>  
>  	if (!np)
> @@ -1878,6 +1877,9 @@ static int serial_imx_probe_dt(struct imx_port *sport,
>  	if (of_get_property(np, "fsl,dte-mode", NULL))
>  		sport->dte_mode = 1;
>  
> +	of_id = of_match_device(imx_uart_dt_ids, &pdev->dev);
> +	if (!of_id)
> +		return -ENODEV;
>  	sport->devdata = of_id->data;
>  
>  	return 0;

I'd do something like:

-	if (!np)
+	sport->devdata = of_device_get_match_data(&pdev->dev);
+	if (!sport->devdata)
 		/* no device tree device */
 		return 1;

instead.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
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