[PATCH] power: supply: cros_charge-control: Avoid accessing attributes out of bounds

[PATCH] power: supply: cros_charge-control: Avoid accessing attributes out of bounds

[Nathan Chancellor]

Clang warns (or errors with CONFIG_WERROR=y):

  drivers/power/supply/cros_charge-control.c:319:2: error: array index 3 is past the end of the array (that has type 'struct attribute *[3]') [-Werror,-Warray-bounds]
    319 |         priv->attributes[_CROS_CHCTL_ATTR_COUNT] = NULL;
        |         ^                ~~~~~~~~~~~~~~~~~~~~~~
  drivers/power/supply/cros_charge-control.c:49:2: note: array 'attributes' declared here
     49 |         struct attribute *attributes[_CROS_CHCTL_ATTR_COUNT];
        |         ^
  1 error generated.

In earlier revisions of the driver, the attributes array in
cros_chctl_priv had four elements with four distinct assignments but
during review, the number of elements was changed to three through use
of an enum and the assignments became a for loop, except for this one,
which is now out of bounds. This assignment is no longer necessary
because the size of the attributes array no longer accounts for it, so
just remove it to clear up the warning.

Fixes: c6ed48ef5259 ("power: supply: add ChromeOS EC based charge control driver")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
 drivers/power/supply/cros_charge-control.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/power/supply/cros_charge-control.c b/drivers/power/supply/cros_charge-control.c
index 73d7f2dc0fa3..2dd8ddbd56bc 100644
--- a/drivers/power/supply/cros_charge-control.c
+++ b/drivers/power/supply/cros_charge-control.c
@@ -316,7 +316,6 @@ static int cros_chctl_probe(struct platform_device *pdev)
 		sysfs_attr_init(&priv->device_attrs[i].attr);
 		priv->attributes[i] = &priv->device_attrs[i].attr;
 	}
-	priv->attributes[_CROS_CHCTL_ATTR_COUNT] = NULL;
 	priv->group.is_visible = cros_chtl_attr_is_visible;
 	priv->group.attrs = priv->attributes;
 

---
base-commit: 3664706e875f84bd4e3fa25ed1c6e46934cb32cd
change-id: 20240702-cros_charge-control-fix-clang-array-bounds-warning-b84fd0f642a0

Best regards,
-- 
Nathan Chancellor <nathan@kernel.org>

Re: [PATCH] power: supply: cros_charge-control: Avoid accessing attributes out of bounds

[Thomas Weißschuh]

Hi Nathan,

Thanks!

On 2024-07-02 07:48:48+0000, Nathan Chancellor wrote:
> Clang warns (or errors with CONFIG_WERROR=y):
> 
>   drivers/power/supply/cros_charge-control.c:319:2: error: array index 3 is past the end of the array (that has type 'struct attribute *[3]') [-Werror,-Warray-bounds]
>     319 |         priv->attributes[_CROS_CHCTL_ATTR_COUNT] = NULL;
>         |         ^                ~~~~~~~~~~~~~~~~~~~~~~
>   drivers/power/supply/cros_charge-control.c:49:2: note: array 'attributes' declared here
>      49 |         struct attribute *attributes[_CROS_CHCTL_ATTR_COUNT];
>         |         ^
>   1 error generated.
> 
> In earlier revisions of the driver, the attributes array in
> cros_chctl_priv had four elements with four distinct assignments but
> during review, the number of elements was changed to three through use
> of an enum and the assignments became a for loop, except for this one,
> which is now out of bounds. This assignment is no longer necessary
> because the size of the attributes array no longer accounts for it, so
> just remove it to clear up the warning.
> 
> Fixes: c6ed48ef5259 ("power: supply: add ChromeOS EC based charge control driver")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>

Acked-by: Thomas Weißschuh <linux@weissschuh.net>

> ---
>  drivers/power/supply/cros_charge-control.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/power/supply/cros_charge-control.c b/drivers/power/supply/cros_charge-control.c
> index 73d7f2dc0fa3..2dd8ddbd56bc 100644
> --- a/drivers/power/supply/cros_charge-control.c
> +++ b/drivers/power/supply/cros_charge-control.c
> @@ -316,7 +316,6 @@ static int cros_chctl_probe(struct platform_device *pdev)
>  		sysfs_attr_init(&priv->device_attrs[i].attr);
>  		priv->attributes[i] = &priv->device_attrs[i].attr;
>  	}
> -	priv->attributes[_CROS_CHCTL_ATTR_COUNT] = NULL;
>  	priv->group.is_visible = cros_chtl_attr_is_visible;
>  	priv->group.attrs = priv->attributes;
>  
> 
> ---
> base-commit: 3664706e875f84bd4e3fa25ed1c6e46934cb32cd
> change-id: 20240702-cros_charge-control-fix-clang-array-bounds-warning-b84fd0f642a0
> 
> Best regards,
> -- 
> Nathan Chancellor <nathan@kernel.org>
> 

Re: [PATCH] power: supply: cros_charge-control: Avoid accessing attributes out of bounds

[Tzung-Bi Shih]

On Tue, Jul 02, 2024 at 07:48:48AM -0700, Nathan Chancellor wrote:
> Clang warns (or errors with CONFIG_WERROR=y):
> 
>   drivers/power/supply/cros_charge-control.c:319:2: error: array index 3 is past the end of the array (that has type 'struct attribute *[3]') [-Werror,-Warray-bounds]
>     319 |         priv->attributes[_CROS_CHCTL_ATTR_COUNT] = NULL;
>         |         ^                ~~~~~~~~~~~~~~~~~~~~~~
>   drivers/power/supply/cros_charge-control.c:49:2: note: array 'attributes' declared here
>      49 |         struct attribute *attributes[_CROS_CHCTL_ATTR_COUNT];
>         |         ^
>   1 error generated.
>
> [...]

Applied to

    https://git.kernel.org/pub/scm/linux/kernel/git/chrome-platform/linux.git for-next

Thanks!

[1/1] power: supply: cros_charge-control: Avoid accessing attributes out of bounds
      commit: c98f17fec35e46629272226a898ebb0a653ee270