Subject: Re: [PATCH 1/1] rtlwifi: Convert drivers to use new API for ieee80211_is_robust_mgmt_frame()

From: Larry Finger <[email-masked]>
Date: Fri, 21 Feb 2014 09:03:34 -0600

On 02/21/2014 08:38 AM, Johannes Berg wrote:
> On Fri, 2014-02-21 at 08:33 -0600, Larry Finger wrote:
>> Drivers rtl8188ee, rtl8192ce, rtl8192se, and rtl8723ae all use this routine.
>> In addition, all callers of ieee80211_is_robust_mgmt_frame() have access to the
>> skb. Thus, it is trivial to use the new API rather than the underscored old version.
>
> Unfortunately, I'm pretty sure this is incorrect. I looked at this code
> before, and take for example:
>
>> +++ b/drivers/net/wireless/rtlwifi/rtl8723ae/trx.c
>> @@ -334,8 +334,8 @@ bool rtl8723ae_rx_query_desc(struct ieee80211_hw *hw,
>>   			/* during testing, hdr could be NULL here */
>>   			return false;
>>   		}
>> -		if ((_ieee80211_is_robust_mgmt_frame(hdr)) &&
>> -			(ieee80211_has_protected(hdr->frame_control)))
>> +		if ((ieee80211_is_robust_mgmt_frame(skb)) &&
>> +		    (ieee80211_has_protected(hdr->frame_control)))
>
> Here, hdr is set like this:
>
>                  hdr = (struct ieee80211_hdr *)(skb->data +
>                         status->rx_drvinfo_size + status->rx_bufshift);
>
> so the skb clearly contains something else before the hdr, and the
> conversion is probably not right because it assumes hdr == skb->data,
> where here it isn't that but instead (skb->data + something).

I thought I had tested the change, but I'm not sure if my AP is using 
ieee802.11w. I need to test this better.

@John: Please drop this patch.

Larry