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

On Fri, Jul 23, 2021 at 5:18 PM Johannes Berg [off-list ref] wrote:

On Fri, 2021-07-23 at 17:13 +0800, Dongliang Mu wrote:

quoted

On Fri, Jul 23, 2021 at 4:37 PM Johannes Berg [off-list ref] wrote:

quoted

On Fri, 2021-07-23 at 13:09 +0800, Dongliang Mu wrote:

quoted

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?

Yes, it saves the regd object in the function wiphy_apply_custom_regulatory.

Right.

quoted

But its parent function - mac80211_hwsim_new_radio forgets to free
this object when the ieee80211_register_hw fails.

But why is this specific to mac80211-hwsim?

Any other code calling wiphy_apply_custom_regulatory() and then failing
the subsequent wiphy_register() or otherwise calling wiphy_free() will
run into the same situation.

So why wouldn't we free this in wiphy_free(), if it exists?

Hi Johannes,

if zhao in the thread is right, we don't need to add this free
operation to wiphy_free().

What we should do is to only handle regd in the error handling code of
mac80211_hwsim_new_radio. This will not affect other users of
mac80211-hwsim. Any idea?

johannes