From: Johannes Berg <johannes@sipsolutions.net>
To: Dongliang Mu <mudongliangabcd@gmail.com>
Cc: Kalle Valo <kvalo@codeaurora.org>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
Luca Coelho <luciano.coelho@intel.com>,
Ilan Peer <ilan.peer@intel.com>,
syzbot+1638e7c770eef6b6c0d0@syzkaller.appspotmail.com,
linux-wireless@vger.kernel.org,
"open list:NETWORKING [GENERAL]" <netdev@vger.kernel.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Dan Carpenter <dan.carpenter@oracle.com>
Subject: Re: [PATCH] cfg80211: free the object allocated in wiphy_apply_custom_regulatory
Date: Fri, 23 Jul 2021 11:42:40 +0200 [thread overview]
Message-ID: <e549fbb09d7c618762996aca4242c2ae50f85a5c.camel@sipsolutions.net> (raw)
In-Reply-To: <CAD-N9QWRNyZnnDQ3XTQ_SAWNEgiMCJV+5Z69eHtRVcxYtXcM+A@mail.gmail.com>
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()
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().
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.
johannes
next prev parent reply other threads:[~2021-07-23 9:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-23 5:09 [PATCH] cfg80211: free the object allocated in wiphy_apply_custom_regulatory Dongliang Mu
2021-07-23 5:16 ` Dongliang Mu
2021-07-23 8:37 ` Johannes Berg
2021-07-23 9:13 ` Dongliang Mu
2021-07-23 9:18 ` Johannes Berg
2021-07-23 9:30 ` Dongliang Mu
2021-07-23 9:42 ` Johannes Berg [this message]
2021-07-23 9:59 ` Dongliang Mu
2021-07-23 9:18 ` xiaoqiang zhao
2021-07-23 9:25 ` Dongliang Mu
2021-07-23 9:36 ` xiaoqiang zhao
2021-07-23 9:44 ` Dongliang Mu
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