Subject: Re: [PATCH] net: dsa: Fix Marvell Egress Trailer check

From: Guenter Roeck <[email-masked]>
Date: Tue, 22 Sep 2015 08:12:06 -0700

On 09/22/2015 02:28 AM, Neil Armstrong wrote:
> The Marvell Egress rx trailer check must be fixed to
> correctly detect bad bits in the third byte of the
> Eggress trailer as described in the Table 28 of the
> 88E6060 datasheet.
> The current code incorrectly omits to check the third
> byte and checks the fourth byte twice.
>
> Signed-off-by: Neil Armstrong <[email-masked]>

Nice catch.

Acked-by: Guenter Roeck <[email-masked]>

> ---
>   net/dsa/tag_trailer.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/dsa/tag_trailer.c b/net/dsa/tag_trailer.c
> index e268f9d..d0526a9 100644
> --- a/net/dsa/tag_trailer.c
> +++ b/net/dsa/tag_trailer.c
> @@ -84,7 +84,7 @@ static int trailer_rcv(struct sk_buff *skb, struct net_device *dev,
>
>   	trailer = skb_tail_pointer(skb) - 4;
>   	if (trailer[0] != 0x80 || (trailer[1] & 0xf8) != 0x00 ||
> -	    (trailer[3] & 0xef) != 0x00 || trailer[3] != 0x00)
> +	    (trailer[2] & 0xef) != 0x00 || trailer[3] != 0x00)
>   		goto out_drop;
>
>   	source_port = trailer[1] & 7;
>