Re: [PATCH] net: openvswitch: ovs_ct_exit to be done under ovs_lock

[Pravin Shelar]

On Sun, Apr 19, 2020 at 1:44 AM <xiangxia.m.yue@xxxxxxxxx> wrote:
>
> From: Tonghao Zhang <xiangxia.m.yue@xxxxxxxxx>
>
> 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@xxxxxxxxxx
> Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit")
> Cc: Pravin B Shelar <pshelar@xxxxxxx>
> Cc: Yi-Hung Wei <yihung.wei@xxxxxxxxx>
> Reported-by: syzbot+7ef50afd3a211f879112@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Tonghao Zhang <xiangxia.m.yue@xxxxxxxxx>

Acked-by: Pravin B Shelar <pshelar@xxxxxxx>

Thanks.