>>> On 03/15/2019 08:28 AM, Stefano Brivio wrote:
>>>> On Fri, 15 Mar 2019 23:18:52 +0800
>>>> Zhiqiang Liu <liuzhiqian...@huawei.com> wrote:
>>>>
>>>>
>>>> NACK, please read my and Eric's comments to v1 -- giving me more than 23
>>>> minutes to answer would have been a nice touch as well :)
>>>>
>>>
>>> Sorry for the confusion, I forgot to add the question marks to my sentences.
>>>
>>> In fact, this is a bug fix, that we missed in the previous fix.
>>>
>>> Technically the bug is older.
>>
>> Please elaborate.
>>
>
> Commit ad6c9986bcb62
> ("vxlan: Fix GRO cells race condition between receive and link delete")
>
> fixed a race condition for the typical case a vxlan device is dismantled from
> the
> current netns.
>
> But if a netns is dismantled, we call vxlan_destroy_tunnels()
> to schedule a unregister_netdevice_queue() of all the vxlan tunnels
> that are related to this netns.
>
> This means that the gro_cells_destroy() call is done too soon,
> for the same reasons explained in above commit .
>
> We need to fully respect the RCU rules, and thus must remove the
> gro_cells_destroy() call or risk use after-free.
>
> The bug is day-0 I think.
>
> commit 58ce31cca1ffe057f4744c3f671e3e84606d3d4a
> Author: Tom Herbert <t...@herbertland.com>
> Date: Wed Aug 19 17:07:33 2015 -0700
>
> vxlan: GRO support at tunnel layer
>
Thank you for pointing out the real issueI will update the commit message and
Fixes: tag as your explanation.
