RE: [PATCH 17/22] platform/x86: alienware-wmi: fix format string overflow warning

[Mario.Limonciello]

> -----Original Message-----
> From: Arnd Bergmann [mailto:arnd@xxxxxxxx]
> Sent: Friday, July 14, 2017 7:07 AM
> To: linux-kernel@xxxxxxxxxxxxxxx; Darren Hart <dvhart@xxxxxxxxxxxxx>; Andy
> Shevchenko <andy@xxxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx>; Guenter Roeck <linux@xxxxxxxxxxxx>;
> akpm@xxxxxxxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; David S . Miller
> <davem@xxxxxxxxxxxxx>; James E . J . Bottomley <jejb@xxxxxxxxxxxxxxxxxx>;
> Martin K . Petersen <martin.petersen@xxxxxxxxxx>; linux-scsi@xxxxxxxxxxxxxxx;
> x86@xxxxxxxxxx; Arnd Bergmann <arnd@xxxxxxxx>; Limonciello, Mario
> <Mario_Limonciello@xxxxxxxx>; Arvind Yadav <arvind.yadav.cs@xxxxxxxxx>;
> platform-driver-x86@xxxxxxxxxxxxxxx
> Subject: [PATCH 17/22] platform/x86: alienware-wmi: fix format string overflow
> warning
> 
> gcc points out a possible format string overflow for a large value of 'zone':
> 
> drivers/platform/x86/alienware-wmi.c: In function 'alienware_wmi_init':
> drivers/platform/x86/alienware-wmi.c:461:24: error: '%02X' directive writing
> between 2 and 8 bytes into a region of size 6 [-Werror=format-overflow=]
>    sprintf(buffer, "zone%02X", i);
>                         ^~~~
> drivers/platform/x86/alienware-wmi.c:461:19: note: directive argument in the
> range [0, 2147483646]
>    sprintf(buffer, "zone%02X", i);
>                    ^~~~~~~~~~
> drivers/platform/x86/alienware-wmi.c:461:3: note: 'sprintf' output between 7 and
> 13 bytes into a destination of size 10
> 
> While the zone should never be that large, it's easy to make the
> buffer a few bytes longer so gcc can prove this to be safe.
> 
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
>  drivers/platform/x86/alienware-wmi.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/platform/x86/alienware-wmi.c
> b/drivers/platform/x86/alienware-wmi.c
> index 0831b428c217..acc01242da82 100644
> --- a/drivers/platform/x86/alienware-wmi.c
> +++ b/drivers/platform/x86/alienware-wmi.c
> @@ -421,7 +421,7 @@ static DEVICE_ATTR(lighting_control_state, 0644,
> show_control_state,
>  static int alienware_zone_init(struct platform_device *dev)
>  {
>  	int i;
> -	char buffer[10];
> +	char buffer[13];
>  	char *name;
> 
>  	if (interface == WMAX) {
> --
> 2.9.0

LGTM,  Thanks.

Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxxx>