2023-07-15 16:07:26

by Zhang Shurong

Subject: [PATCH] bus: imx-weim: fix to avoid potential NULL pointer dereference

of_match_device() may fail and returns a NULL pointer.

Fix this by checking the return value of of_match_device.

Fixes: 3f98b6baad63 ("drivers: bus: imx-weim: Add support for i.MX1/21/25/27/31/35/50/51/53")
Signed-off-by: Zhang Shurong <[email protected]>
---
drivers/bus/imx-weim.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
index 52a5d0447390..65402bb60c18 100644
--- a/drivers/bus/imx-weim.c
+++ b/drivers/bus/imx-weim.c
@@ -202,15 +202,19 @@ static int weim_timing_setup(struct device *dev, struct device_node *np,

static int weim_parse_dt(struct platform_device *pdev)
{
- const struct of_device_id *of_id = of_match_device(weim_id_table,
- &pdev->dev);
- const struct imx_weim_devtype *devtype = of_id->data;
+ const struct of_device_id *of_id;
+ const struct imx_weim_devtype *devtype;
int ret = 0, have_child = 0;
struct device_node *child;
struct weim_priv *priv;
void __iomem *base;
u32 reg;

+ of_id = of_match_device(weim_id_table, &pdev->dev);
+ if (!of_id)
+ return -EINVAL;
+
+ devtype = of_id->data;
if (devtype == &imx50_weim_devtype) {
ret = imx_weim_gpr_setup(pdev);
if (ret)
--
2.30.2

2023-07-15 16:59:28

by Fabio Estevam

Subject: Re: [PATCH] bus: imx-weim: fix to avoid potential NULL pointer dereference

Hi Zhang,

On Sat, Jul 15, 2023 at 12:21 PM Zhang Shurong
<[email protected]> wrote:
>
> of_match_device() may fail and returns a NULL pointer.
>
> Fix this by checking the return value of of_match_device.
>
> Fixes: 3f98b6baad63 ("drivers: bus: imx-weim: Add support for i.MX1/21/25/27/31/35/50/51/53")
> Signed-off-by: Zhang Shurong <[email protected]>
> ---
> drivers/bus/imx-weim.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/bus/imx-weim.c b/drivers/bus/imx-weim.c
> index 52a5d0447390..65402bb60c18 100644
> --- a/drivers/bus/imx-weim.c
> +++ b/drivers/bus/imx-weim.c
> @@ -202,15 +202,19 @@ static int weim_timing_setup(struct device *dev, struct device_node *np,
>
> static int weim_parse_dt(struct platform_device *pdev)
> {
> - const struct of_device_id *of_id = of_match_device(weim_id_table,
> - &pdev->dev);
> - const struct imx_weim_devtype *devtype = of_id->data;
> + const struct of_device_id *of_id;
> + const struct imx_weim_devtype *devtype;
> int ret = 0, have_child = 0;
> struct device_node *child;
> struct weim_priv *priv;
> void __iomem *base;
> u32 reg;
>
> + of_id = of_match_device(weim_id_table, &pdev->dev);
> + if (!of_id)
> + return -EINVAL;

If there is no match the driver will not probe in the first place.

I don't think this check is needed.