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From:   Pravin Shelar <pravin.ovn@gmail.com>
Date:   Sun, 19 Apr 2020 10:32:30 -0700
Message-ID: <CAOrHB_CjZ1oyNyuj7tgZLZ1XXFahCSO76BfHX7YFo_O68FfrXQ@mail.gmail.com>
Subject: Re: [PATCH] net: openvswitch: ovs_ct_exit to be done under ovs_lock
To:     Tonghao Zhang <xiangxia.m.yue@gmail.com>
Cc:     syzbot+7ef50afd3a211f879112@syzkaller.appspotmail.com,
        "David S. Miller" <davem@davemloft.net>,
        ovs dev <dev@openvswitch.org>, kuba@kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Linux Kernel Network Developers <netdev@vger.kernel.org>,
        syzkaller-bugs@googlegroups.com, Yi-Hung Wei <yihung.wei@gmail.com>
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On Sun, Apr 19, 2020 at 1:44 AM <xiangxia.m.yue@gmail.com> wrote:
>
> From: Tonghao Zhang <xiangxia.m.yue@gmail.com>
>
> syzbot wrote:
> | =============================
> | WARNING: suspicious RCU usage
> | 5.7.0-rc1+ #45 Not tainted
> | -----------------------------
> | net/openvswitch/conntrack.c:1898 RCU-list traversed in non-reader section!!
> |
> | other info that might help us debug this:
> | rcu_scheduler_active = 2, debug_locks = 1
> | ...
> |
> | stack backtrace:
> | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-0-ga698c8995f-prebuilt.qemu.org 04/01/2014
> | Workqueue: netns cleanup_net
> | Call Trace:
> | ...
> | ovs_ct_exit
> | ovs_exit_net
> | ops_exit_list.isra.7
> | cleanup_net
> | process_one_work
> | worker_thread
>
> To avoid that warning, invoke the ovs_ct_exit under ovs_lock and add
> lockdep_ovsl_is_held as optional lockdep expression.
>
> Link: https://lore.kernel.org/lkml/000000000000e642a905a0cbee6e@google.com
> Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit")
> Cc: Pravin B Shelar <pshelar@ovn.org>
> Cc: Yi-Hung Wei <yihung.wei@gmail.com>
> Reported-by: syzbot+7ef50afd3a211f879112@syzkaller.appspotmail.com
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@gmail.com>

Acked-by: Pravin B Shelar <pshelar@ovn.org>

Thanks.