Re: [PATCH] mac80211: Don't inspect Sequence Control field on control frames

[Christian Lamparter <chunkeey@googlemail.com>]

On Thursday, October 25, 2012 08:10:18 PM Javier Cardona wrote:
> Per IEEE Std. 802.11-2012, Sec 8.2.4.4.1, the sequence Control field is
> not present in control frames.  We noticed this problem when processing
> Block Ack Requests.
> 
> Signed-off-by: Javier Cardona <javier@cozybit.com>
> Signed-off-by: Javier Lopez <jlopex@cozybit.com>
> ---
>  net/mac80211/rx.c |    4 ++++
>  1 files changed, 4 insertions(+), 0 deletions(-)
> 
> diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
> index f975f64..bf54336 100644
> --- a/net/mac80211/rx.c
> +++ b/net/mac80211/rx.c
> @@ -1467,6 +1467,10 @@ ieee80211_rx_h_defragment(struct ieee80211_rx_data *rx)
>  
>  	hdr = (struct ieee80211_hdr *)rx->skb->data;
>  	fc = hdr->frame_control;
> +
> +	if (ieee80211_is_ctl(fc))
> +		return RX_CONTINUE;
> +
>  	sc = le16_to_cpu(hdr->seq_ctrl);
>  	frag = sc & IEEE80211_SCTL_FRAG;
>  
hmm, I see this function also calls skb_linearize() on said
skb... Does anybody know of any possible side effects? Not
that control frames (In fact, just BlockACK Requests come
to my mind) usually so large...

Regards,
	Chr