2022-03-04 12:01:54

by Xiaoke Wang

Subject: [PATCH] media: omap3isp: check the return of __ccp2_get_format()

From: Xiaoke Wang <[email protected]>

__ccp2_get_format() returns format structure or NULL on error.
So it is better to check the return value of it to prevent potential
wrong memory access.

Signed-off-by: Xiaoke Wang <[email protected]>
---
drivers/media/platform/omap3isp/ispccp2.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/media/platform/omap3isp/ispccp2.c b/drivers/media/platform/omap3isp/ispccp2.c
index acb58b6..81881b1 100644
--- a/drivers/media/platform/omap3isp/ispccp2.c
+++ b/drivers/media/platform/omap3isp/ispccp2.c
@@ -675,8 +675,10 @@ static void ccp2_try_format(struct isp_ccp2_device *ccp2,
*/
format = __ccp2_get_format(ccp2, sd_state, CCP2_PAD_SINK,
which);
- memcpy(fmt, format, sizeof(*fmt));
- fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;
+ if (format != NULL) {
+ memcpy(fmt, format, sizeof(*fmt));
+ fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;
+ }
break;
}

@@ -709,6 +711,9 @@ static int ccp2_enum_mbus_code(struct v4l2_subdev *sd,

format = __ccp2_get_format(ccp2, sd_state, CCP2_PAD_SINK,
code->which);
+ if (format == NULL)
+ return -EINVAL;
+
code->code = format->code;
}

@@ -792,6 +797,9 @@ static int ccp2_set_format(struct v4l2_subdev *sd,
if (fmt->pad == CCP2_PAD_SINK) {
format = __ccp2_get_format(ccp2, sd_state, CCP2_PAD_SOURCE,
fmt->which);
+ if (format == NULL)
+ return -EINVAL;
+
*format = fmt->format;
ccp2_try_format(ccp2, sd_state, CCP2_PAD_SOURCE, format,
fmt->which);
--

2022-03-04 20:46:36

by Laurent Pinchart

Subject: Re: [PATCH] media: omap3isp: check the return of __ccp2_get_format()

Hello Xiaoke,

Thank you for the patch.

On Fri, Mar 04, 2022 at 07:48:18PM +0800, [email protected] wrote:
> From: Xiaoke Wang <[email protected]>
>
> __ccp2_get_format() returns format structure or NULL on error.
> So it is better to check the return value of it to prevent potential
> wrong memory access.

The function can actually never return NULL if it's called with a valid
pad number, which should always be the case as far as I can tell (since
commit a8fa55078a778). This patch is thus not needed.

> Signed-off-by: Xiaoke Wang <[email protected]>
> ---
> drivers/media/platform/omap3isp/ispccp2.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/media/platform/omap3isp/ispccp2.c b/drivers/media/platform/omap3isp/ispccp2.c
> index acb58b6..81881b1 100644
> --- a/drivers/media/platform/omap3isp/ispccp2.c
> +++ b/drivers/media/platform/omap3isp/ispccp2.c
> @@ -675,8 +675,10 @@ static void ccp2_try_format(struct isp_ccp2_device *ccp2,
> */
> format = __ccp2_get_format(ccp2, sd_state, CCP2_PAD_SINK,
> which);
> - memcpy(fmt, format, sizeof(*fmt));
> - fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;
> + if (format != NULL) {
> + memcpy(fmt, format, sizeof(*fmt));
> + fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;
> + }
> break;
> }
>
> @@ -709,6 +711,9 @@ static int ccp2_enum_mbus_code(struct v4l2_subdev *sd,
>
> format = __ccp2_get_format(ccp2, sd_state, CCP2_PAD_SINK,
> code->which);
> + if (format == NULL)
> + return -EINVAL;
> +
> code->code = format->code;
> }
>
> @@ -792,6 +797,9 @@ static int ccp2_set_format(struct v4l2_subdev *sd,
> if (fmt->pad == CCP2_PAD_SINK) {
> format = __ccp2_get_format(ccp2, sd_state, CCP2_PAD_SOURCE,
> fmt->which);
> + if (format == NULL)
> + return -EINVAL;
> +
> *format = fmt->format;
> ccp2_try_format(ccp2, sd_state, CCP2_PAD_SOURCE, format,
> fmt->which);

--
Regards,

Laurent Pinchart