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From: Jamal Hadi Salim <jhs@mojatatu•com>
To: Cong Wang <xiyou.wangcong@gmail•com>, netdev@vger•kernel.org
Cc: John Fastabend <john.fastabend@gmail•com>,
	Cong Wang <cwang@twopensource•com>
Subject: Re: [Patch net] act_mirred: fix a race condition on mirred_list
Date: Mon, 5 Oct 2015 08:07:28 -0400	[thread overview]
Message-ID: <56126800.2030600@mojatatu.com> (raw)
In-Reply-To: <561265EC.6050906@mojatatu.com>


Never mind. Mirred is speacial because it points to other netdevs.
So:

Acked-by: Jamal Hadi Salim <jhs@mojatatu•com>

Thanks Cong.

cheers,
jamal

On 10/05/15 07:58, Jamal Hadi Salim wrote:
> Hi Cong,
>
> I am wondering if making the bindcount or refcount atomic would help?
> How does this bug get created? i.e the RTNL is still around.
> Why is this specific to mirred only?
>
> cheers,
> jamal
>
>
> On 10/01/15 14:37, Cong Wang wrote:
>> After commit 1ce87720d456 ("net: sched: make cls_u32 lockless")
>> we began to release tc actions in a RCU callback. However,
>> mirred action relies on RTNL lock to protect the global
>> mirred_list, therefore we could have a race condition
>> between RCU callback and netdevice event, which caused
>> a list corruption as reported by Vinson.
>>
>> Instead of relying on RTNL lock, introduce a spinlock to
>> protect this list.
>>
>> Note, in non-bind case, it is still called with RTNL lock,
>> therefore should disable BH too.
>>

  reply	other threads:[~2015-10-05 12:07 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-01 18:37 [Patch net] act_mirred: fix a race condition on mirred_list Cong Wang
2015-10-01 18:37 ` [Patch net] act_mirred: always release tcf hash Cong Wang
2015-10-05 12:14   ` Jamal Hadi Salim
2015-10-05 13:31   ` David Miller
2015-10-05 11:58 ` [Patch net] act_mirred: fix a race condition on mirred_list Jamal Hadi Salim
2015-10-05 12:07   ` Jamal Hadi Salim [this message]
2015-10-05 13:31 ` David Miller

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