On Fri, Jul 23, 2021 at 5:42 PM Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > > Hi, > > On Fri, 2021-07-23 at 17:30 +0800, Dongliang Mu wrote: > > if zhao in the thread is right, we don't need to add this free > > operation to wiphy_free(). > > Actually, no, that statement is not true. > > All that zhao claimed was that the free happens correctly during > unregister (or later), and that is indeed true, since it happens from > > ieee80211_unregister_hw() > -> wiphy_unregister() > -> wiphy_regulatory_deregister() > Thanks for your explanation. Now the situation is more clear. > > However, syzbot of course is also correct. Abstracting a bit and > ignoring mac80211, the problem is that here we assign it before > wiphy_register(), then wiphy_register() doesn't get called or fails, and > therefore we don't call wiphy_unregister(), only wiphy_free(). Yes, you're right. In this case, wiphy_register is not called. We should not call wiphy_unregister() to clean up anything. > > Hence the leak. > > But you can also easily see from that description that it's not related > to hwsim - we should add a secondary round of cleanups in wiphy_free() > or even move the call to wiphy_regulatory_deregister() into > wiphy_free(), we need to look what else this does to see if we can move > it or not. I agree to move the cleanup operation of regd to wiphy_free API. That's the partial functionability of this function. > > johannes >
