From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jason Wang <jasowang@redhat.com>
Subject: Re: Possible unsafe usage of skb->cb in virtio-net
Date: Tue, 19 Dec 2017 17:06:25 +0800
Message-ID: <2cb1512d-2db5-34a5-21c0-dd3fa2db8ad1@redhat.com>
References: <VI1PR0501MB2734AAE4311FE84881F622A2D45C0@VI1PR0501MB2734.eurprd05.prod.outlook.com>
	<20171102142758-mutt-send-email-mst@kernel.org>
Mime-Version: 1.0
Content-Type: text/plain; charset="utf-8"; Format="flowed"
Content-Transfer-Encoding: base64
Cc: netdev@vger.kernel.org, Willem de Bruijn <willemb@google.com>,
	David Miller <davem@davemloft.net>,
	virtualization@lists.linux-foundation.org
To: "Michael S. Tsirkin" <mst@redhat.com>, Ilya Lesokhin <ilyal@mellanox.com>
Return-path: <virtualization-bounces@lists.linux-foundation.org>
In-Reply-To: <20171102142758-mutt-send-email-mst@kernel.org>
Content-Language: en-US
List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/virtualization>,
	<mailto:virtualization-request@lists.linux-foundation.org?subject=unsubscribe>
List-Archive: <http://lists.linuxfoundation.org/pipermail/virtualization/>
List-Post: <mailto:virtualization@lists.linux-foundation.org>
List-Help: <mailto:virtualization-request@lists.linux-foundation.org?subject=help>
List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/virtualization>,
	<mailto:virtualization-request@lists.linux-foundation.org?subject=subscribe>
Sender: virtualization-bounces@lists.linux-foundation.org
Errors-To: virtualization-bounces@lists.linux-foundation.org
List-Id: netdev.vger.kernel.org
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