Netdev Archive on lore.kernel.org
help / color / mirror / Atom feed
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


  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 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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=e549fbb09d7c618762996aca4242c2ae50f85a5c.camel@sipsolutions.net \
    --to=johannes@sipsolutions.net \
    --cc=dan.carpenter@oracle.com \
    --cc=davem@davemloft.net \
    --cc=ilan.peer@intel.com \
    --cc=kuba@kernel.org \
    --cc=kvalo@codeaurora.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=luciano.coelho@intel.com \
    --cc=mudongliangabcd@gmail.com \
    --cc=netdev@vger.kernel.org \
    --cc=syzbot+1638e7c770eef6b6c0d0@syzkaller.appspotmail.com \
    --subject='Re: [PATCH] cfg80211: free the object allocated in wiphy_apply_custom_regulatory' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).