Re: [PATCH] MIPS: BCM63XX: properly handle mac address octet overflow

[Sergei Shtylyov <sshtylyov@mvista.com>]

Hello.

On 18-09-2012 13:32, Jonas Gorski wrote:

> While calculating the mac address the pointer for the current octet was
> never reset back to the least significant one after being decremented
> because of an octet overflow. This resulted in the code continuing to
> increment at the current octet, potentially generating duplicate or
> invalid mac addresses.

> As a second issue the pointer was allowed to advance up to the most
> significant octet, modifying the OUI, and potentially changing the type
> of mac address.

> Rewrite the code so it resets the pointer to the least significant
> in each outer loop step, and bails out when the least significant octet
> of the OUI is reached.

> Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
> ---
>   arch/mips/bcm63xx/boards/board_bcm963xx.c |   16 +++++++++-------
>   1 file changed, 9 insertions(+), 7 deletions(-)

> diff --git a/arch/mips/bcm63xx/boards/board_bcm963xx.c b/arch/mips/bcm63xx/boards/board_bcm963xx.c
> index ea4ea77..f0fcec6 100644
> --- a/arch/mips/bcm63xx/boards/board_bcm963xx.c
> +++ b/arch/mips/bcm63xx/boards/board_bcm963xx.c
> @@ -720,7 +720,7 @@ const char *board_get_name(void)
>    */
>   static int board_get_mac_address(u8 *mac)
>   {
> -	u8 *p;
> +	u8 *oui;
>   	int count;
>
>   	if (mac_addr_used >= nvram.mac_addr_count) {
> @@ -729,21 +729,23 @@ static int board_get_mac_address(u8 *mac)
>   	}
>
>   	memcpy(mac, nvram.mac_addr_base, ETH_ALEN);
> -	p = mac + ETH_ALEN - 1;
> +	oui = mac + ETH_ALEN/2 - 1;
>   	count = mac_addr_used;
>
>   	while (count--) {
> +		p = mac + ETH_ALEN - 1;

    But didn't you remove 'p' above? Did you compile this?

WBR, Sergei