Re: [PATCH net-next] phy: mscc: fix printf format

[Alexandre Belloni]

On 26/09/2018 15:20:11+0200, Arnd Bergmann wrote:
> gcc points out that the length of the temporary buffer may not be sufficient for
> large numbers of leds:
> 
> drivers/net/phy/mscc.c: In function 'vsc85xx_probe':
> drivers/net/phy/mscc.c:460:45: error: '-mode' directive writing 5 bytes into a region of size between 0 and 9 [-Werror=format-overflow=]
>    ret = sprintf(led_dt_prop, "vsc8531,led-%d-mode", i);
>                                              ^~~~~
> drivers/net/phy/mscc.c:460:9: note: 'sprintf' output between 19 and 28 bytes into a destination of size 22
>    ret = sprintf(led_dt_prop, "vsc8531,led-%d-mode", i);
>          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> While we can make a reasonable assumption that the number of LEDs is small,
> the cost of making the buffer a little bigger is insignificant as well.
> 
> Fixes: 11bfdabb7ff5 ("net: phy: mscc: factorize code for LEDs mode")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
Reviewed-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>

> ---
>  drivers/net/phy/mscc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/phy/mscc.c b/drivers/net/phy/mscc.c
> index 2d9676d78d3f..7d0384e26c99 100644
> --- a/drivers/net/phy/mscc.c
> +++ b/drivers/net/phy/mscc.c
> @@ -453,7 +453,7 @@ static int vsc85xx_dt_led_modes_get(struct phy_device *phydev,
>  				    u32 *default_mode)
>  {
>  	struct vsc8531_private *priv = phydev->priv;
> -	char led_dt_prop[19];
> +	char led_dt_prop[28];
>  	int i, ret;
>  
>  	for (i = 0; i < priv->nleds; i++) {
> -- 
> 2.18.0
> 

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com