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From: Johannes Berg <johannes@sipsolutions.net>
To: linux-wireless@vger.kernel.org
Cc: Johannes Berg <johannes.berg@intel.com>,
	stable@vger.kernel.org,
	syzbot+11c342e5e30e9539cabd@syzkaller.appspotmail.com
Subject: [PATCH] mac80211: fix locking in ieee80211_start_ap error path
Date: Mon, 20 Dec 2021 09:08:40 +0100	[thread overview]
Message-ID: <20211220090836.cee3d59a1915.I36bba9b79dc2ff4d57c3c7aa30dff9a003fe8c5c@changeid> (raw)

From: Johannes Berg <johannes.berg@intel.com>

We need to hold the local->mtx to release the channel context,
as even encoded by the lockdep_assert_held() there. Fix it.

Cc: stable@vger.kernel.org
Fixes: 295b02c4be74 ("mac80211: Add FILS discovery support")
Reported-by: syzbot+11c342e5e30e9539cabd@syzkaller.appspotmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git master
---
 net/mac80211/cfg.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c
index bd3d3195097f..2d0dd69f9753 100644
--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -1264,7 +1264,10 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev,
 	return 0;
 
 error:
+	mutex_lock(&local->mtx);
 	ieee80211_vif_release_channel(sdata);
+	mutex_unlock(&local->mtx);
+
 	return err;
 }
 
-- 
2.33.1


             reply	other threads:[~2021-12-20  8:09 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-12-20  8:08 Johannes Berg [this message]
2021-12-20  8:36 ` [syzbot] WARNING in ieee80211_vif_release_channel (2) syzbot

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