Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <9e2b850b81c44e41c3cc8dbd8c4ab61e516b85b8.camel@redhat.com>
Subject: Re: [PATCH net-next v3 0/3] net: ipvlan: fix potential UAF problem
 for phy_dev
From:   Paolo Abeni <pabeni@redhat.com>
To:     Ziyang Xuan <william.xuanziyang@huawei.com>, davem@davemloft.net,
        kuba@kernel.org, netdev@vger.kernel.org
Cc:     edumazet@google.com, brianvv@google.com,
        linux-kernel@vger.kernel.org
Date:   Tue, 22 Mar 2022 10:15:21 +0100
In-Reply-To: <cover.1647664114.git.william.xuanziyang@huawei.com>
References: <cover.1647664114.git.william.xuanziyang@huawei.com>
Content-Type: text/plain; charset="UTF-8"
User-Agent: Evolution 3.42.4 (3.42.4-1.fc35) 
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit
Precedence: bulk

Hello,

On Sat, 2022-03-19 at 17:52 +0800, Ziyang Xuan wrote:
> There is a known scenario can trigger UAF problem for lower
> netdevice as following:
> 
> Someone module puts the NETDEV_UNREGISTER event handler to a
> work, and lower netdevice is accessed in the work handler. But
> when the work is excuted, lower netdevice has been destroyed
> because upper netdevice did not get reference to lower netdevice
> correctly.
> 
> Although it can not happen for ipvlan now because there is no
> way to access phy_dev outside ipvlan. But it is necessary to
> add the reference operation to phy_dev to avoid the potential
> UAF problem in the future.
> 
> In addition, add net device refcount tracker to ipvlan and
> fix some error comments for ipvtap module.

This is pure net-next material, and we are now into the merge window -
only fixes allowed. Please repost in 2w, thanks!

Paolo