Re: [RFC 2/2] cfg80211: amend regulatory NULL dereference fix

[Johannes Berg <johannes@sipsolutions.net>]

On Wed, 2011-11-23 at 10:04 -0500, Luis R. Rodriguez wrote:
> Johannes' patch for "cfg80211: fix regulatory NULL dereference"
> broke user regulaotry hints and it did not address the fact that
> last_request was left populated even if the previous regulatory
> hint was stale due to the wiphy disappearing.
> 
> Fix user reguluatory hints by only bailing out if for those
> regulatory hints where a request_wiphy is expected. The stale last_request
> considerations are addressed through the previous fixes on last_request
> where we reset the last_request to a static world regdom request upon
> reset_regdomains(). In this case though we further enhance the effect
> by simply restoring reguluatory settings completely.
> 
> Cc: stable@vger.kernel.org
> Cc: Johannes Berg <johannes.berg@intel.com>
> Signed-off-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
> ---
>  net/wireless/reg.c |    6 ++++--
>  1 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/net/wireless/reg.c b/net/wireless/reg.c
> index df73b96..6049050 100644
> --- a/net/wireless/reg.c
> +++ b/net/wireless/reg.c
> @@ -2091,8 +2091,10 @@ static int __set_regdom(const struct ieee80211_regdomain *rd)
>  	}
>  
>  	request_wiphy = wiphy_idx_to_wiphy(last_request->wiphy_idx);
> -	if (!request_wiphy) {
> -		reg_set_request_processed();
> +	if (!request_wiphy &&
> +	    (last_request->initiator == NL80211_REGDOM_SET_BY_DRIVER ||
> +	     last_request->initiator == NL80211_REGDOM_SET_BY_COUNTRY_IE)) {
> +		schedule_delayed_work(&reg_timeout, 0);
>  		return -ENODEV;

This seems OK to me, but the function is really hard to follow -- maybe
(later) we should take some code duplication and make it easier to read
by switching on the type of hint first?

johannes