Re: [PATCH 09/22] net: niu: fix format string overflow warning:

From: David Miller
Date: Fri Jul 14 2017 - 12:03:54 EST


From: Arnd Bergmann <arnd@xxxxxxxx>
Date: Fri, 14 Jul 2017 14:07:01 +0200

> We get a warning for the port_name string that might be longer than
> six characters if we had more than 10 ports:
>
> drivers/net/ethernet/sun/niu.c: In function 'niu_put_parent':
> drivers/net/ethernet/sun/niu.c:9563:21: error: '%d' directive writing between 1 and 3 bytes into a region of size 2 [-Werror=format-overflow=]
> sprintf(port_name, "port%d", port);
> ^~~~~~~~
> drivers/net/ethernet/sun/niu.c:9563:21: note: directive argument in the range [0, 255]
> drivers/net/ethernet/sun/niu.c:9563:2: note: 'sprintf' output between 6 and 8 bytes into a destination of size 6
> sprintf(port_name, "port%d", port);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> drivers/net/ethernet/sun/niu.c: In function 'niu_pci_init_one':
> drivers/net/ethernet/sun/niu.c:9538:22: error: '%d' directive writing between 1 and 3 bytes into a region of size 2 [-Werror=format-overflow=]
> sprintf(port_name, "port%d", port);
> ^~~~~~~~
> drivers/net/ethernet/sun/niu.c:9538:22: note: directive argument in the range [0, 255]
> drivers/net/ethernet/sun/niu.c:9538:3: note: 'sprintf' output between 6 and 8 bytes into a destination of size 6
>
> While we know that the port number is small, there is no harm in
> making the format string two bytes longer to avoid the warning.
>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>

Applied.