lkml.org 
[lkml]   [2023]   [Jan]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] media: v4l2-flash: fix NULL dereference in v4l2_flash_s_ctrl()
Hi Alexandr,

On Wed, Dec 07, 2022 at 05:18:07PM +0300, Aleksandr Burakov wrote:
> The NULL check added for fled_cdev before dereference.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Signed-off-by: Aleksandr Burakov <a.burakov@rosalinux.ru>
> Fixes: 42bd6f59ae90 ("media: Add registration helpers for V4L2 flash sub-devices")
> ---
> drivers/media/v4l2-core/v4l2-flash-led-class.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-flash-led-class.c b/drivers/media/v4l2-core/v4l2-flash-led-class.c
> index 355595a0fefa..36cc46e80eea 100644
> --- a/drivers/media/v4l2-core/v4l2-flash-led-class.c
> +++ b/drivers/media/v4l2-core/v4l2-flash-led-class.c
> @@ -291,12 +291,16 @@ static int v4l2_flash_s_ctrl(struct v4l2_ctrl *c)
> * No conversion is needed as LED Flash class also uses
> * microseconds for flash timeout units.
> */
> + if (!fled_cdev)
> + return -EINVAL;
> return led_set_flash_timeout(fled_cdev, c->val);
> case V4L2_CID_FLASH_INTENSITY:
> /*
> * No conversion is needed as LED Flash class also uses
> * microamperes for flash intensity units.
> */
> + if (!fled_cdev)
> + return -EINVAL;
> return led_set_flash_brightness(fled_cdev, c->val);
> }
>

fled_cdev won't be NULL above, this is checked elsewhere in the V4L2 flash
LED class code. I guess the question then is whether doing such a check is
meaningful. It would require a bug elsewhere in the code to happen.

--
Kind regards,

Sakari Ailus

\
 
 \ /
  Last update: 2023-03-26 23:43    [W:0.418 / U:3.596 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site