Re: [PATCH] cfg80211: free the object allocated in wiphy_apply_custom_regulatory

From: Johannes Berg
Date: Fri Jul 23 2021 - 04:38:05 EST


On Fri, 2021-07-23 at 13:09 +0800, Dongliang Mu wrote:
> The commit beee24695157 ("cfg80211: Save the regulatory domain when
> setting custom regulatory") forgets to free the newly allocated regd
> object.

Not really? It's not forgetting it, it just saves it?

+ new_regd = reg_copy_regd(regd);
+ if (IS_ERR(new_regd))
+ return;
+
+ tmp = get_wiphy_regdom(wiphy);
+ rcu_assign_pointer(wiphy->regd, new_regd);
+ rcu_free_regdom(tmp);

> Fix this by freeing the regd object in the error handling code and
> deletion function - mac80211_hwsim_del_radio.

This can't be right - the same would affect all other users of that
function, no?

Perhaps somewhere we have a case where wiphy->regd is leaked, but than
that should be fixed more generally in cfg80211?

johannes