Re: [PATCH v2 44/63] mac80211: Use memset_after() to clear tx status

[Johannes Berg]

On Tue, 2021-08-17 at 23:05 -0700, Kees Cook wrote:
> 
> @@ -275,12 +275,11 @@ static void carl9170_tx_release(struct kref *ref)
>  	if (WARN_ON_ONCE(!ar))
>  		return;
>  
> 
> 
> 
> -	BUILD_BUG_ON(
> -	    offsetof(struct ieee80211_tx_info, status.ack_signal) != 20);
> -
> -	memset(&txinfo->status.ack_signal, 0,
> -	       sizeof(struct ieee80211_tx_info) -
> -	       offsetof(struct ieee80211_tx_info, status.ack_signal));
> +	/*
> +	 * Should this call ieee80211_tx_info_clear_status() instead of clearing
> +	 * manually? txinfo->status.rates do not seem to be used here.
> +	 */

Since you insist, I went digging :)

It should not, carl9170_tx_fill_rateinfo() has filled the rate
information before we get to this point.

johannes