Subject: Re: [PATCH 08/32] staging: wfx: simplify hif_handle_tx_data()

From: Dan Carpenter <[email-masked]>
Date: Thu, 2 Apr 2020 16:13:39 +0300

On Wed, Apr 01, 2020 at 01:03:41PM +0200, Jerome Pouiller wrote:
> From: Jérôme Pouiller <[email-masked]>
> 
> The last argument of hif_handle_tx_data() was now unused. In add,
> hif_handle_tx_data() has nothing to do with HIF layer and should be
> renamed. Finally, it not convenient to pass a wfx_vif as parameter. It
> is easier to let hif_handle_tx_data() find the interface itself.
> 
> Signed-off-by: Jérôme Pouiller <[email-masked]>
> ---
>  drivers/staging/wfx/queue.c | 19 ++++++++++---------
>  1 file changed, 10 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/staging/wfx/queue.c b/drivers/staging/wfx/queue.c
> index 2553f77522d9..8647731e02c0 100644
> --- a/drivers/staging/wfx/queue.c
> +++ b/drivers/staging/wfx/queue.c
> @@ -319,13 +319,17 @@ bool wfx_tx_queues_is_empty(struct wfx_dev *wdev)
>  	return ret;
>  }
>  
> -static bool hif_handle_tx_data(struct wfx_vif *wvif, struct sk_buff *skb,
> -			       struct wfx_queue *queue)
> +static bool wfx_handle_tx_data(struct wfx_dev *wdev, struct sk_buff *skb)
>  {
>  	struct hif_req_tx *req = wfx_skb_txreq(skb);
>  	struct ieee80211_key_conf *hw_key = wfx_skb_tx_priv(skb)->hw_key;
>  	struct ieee80211_hdr *frame =
>  		(struct ieee80211_hdr *)(req->frame + req->data_flags.fc_offset);
> +	struct wfx_vif *wvif =
> +		wdev_to_wvif(wdev, ((struct hif_msg *)skb->data)->interface);
                                                      ^^^^^^^^^
This is on the TX side so it's probably okay, but one problem I have
noticed is that we do this on the RX side as well with checking that

	if (skb->len < sizeof(struct hif_msg))
		return -EINVAL;

So we could be reading beyond the end of the skb.  If we got really
unlucky it could lead to an Oops.

regards,
dan carpenter