2015-11-12 07:46:27

by Corentin Labbe

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

of_match_device could return NULL, and so cause a NULL pointer
dereference later.

Signed-off-by: LABBE Corentin <[email protected]>
---
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;
--
2.4.10

2015-11-16 12:14:50

by Uwe Kleine-König

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

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 <[email protected]>
> ---
> 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

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