From: Stephen Hemminger <stephen@networkplumber.org>
To: Jeongjun Park <aha310510@gmail.com>
Cc: jiri@resnulli.us,
syzbot+705c61d60b091ef42c04@syzkaller.appspotmail.com,
davem@davemloft.net, edumazet@google.com, kuba@kernel.org,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
pabeni@redhat.com, syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH net,v2] team: Fix ABBA deadlock caused by race in team_del_slave
Date: Sat, 6 Jul 2024 08:01:02 -0700 [thread overview]
Message-ID: <20240706080102.1cccb499@hermes.local> (raw)
In-Reply-To: <20240706041329.96637-1-aha310510@gmail.com>
On Sat, 6 Jul 2024 13:13:29 +0900
Jeongjun Park <aha310510@gmail.com> wrote:
> CPU0 CPU1
> ---- ----
> lock(&rdev->wiphy.mtx);
> lock(team->team_lock_key#4);
> lock(&rdev->wiphy.mtx);
> lock(team->team_lock_key#4);
>
> Deadlock occurs due to the above scenario. Therefore, you can prevent
> deadlock by briefly releasing the lock before calling dev_open() in
> team_port_add() and locking it again after it returns.
>
> Reported-and-tested-by: syzbot+705c61d60b091ef42c04@syzkaller.appspotmail.com
> Fixes: 3d249d4ca7d0 ("net: introduce ethernet teaming device")
> Signed-off-by: Jeongjun Park <aha310510@gmail.com>
> ---
But if you drop the lock the actual data structures might have changed.
Usually not a good idea,
prev parent reply other threads:[~2024-07-06 15:01 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-26 11:59 [syzbot] [net?] possible deadlock in team_del_slave (3) syzbot
2024-04-26 14:17 ` Hillf Danton
2024-07-03 14:51 ` [PATCH net] team: Fix ABBA deadlock caused by race in team_del_slave Jeongjun Park
2024-07-03 15:18 ` Michal Kubiak
2024-07-03 16:02 ` Jeongjun Park
2024-07-03 16:30 ` Eric Dumazet
2024-07-05 15:17 ` [syzbot] [net?] possible deadlock in team_del_slave (3) Jeongjun Park
2024-07-05 15:19 ` [PATCH net] team: Fix ABBA deadlock caused by race in team_del_slave Jeongjun Park
2024-07-04 10:15 ` [syzbot] [net?] possible deadlock in team_del_slave (3) Jiri Pirko
2024-07-06 4:13 ` [PATCH net,v2] team: Fix ABBA deadlock caused by race in team_del_slave Jeongjun Park
2024-07-06 15:01 ` Stephen Hemminger [this message]
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