From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergei Shtylyov Subject: Re: [PATCH net] virtio-net: drop NETIF_F_FRAGLIST Date: Tue, 4 Aug 2015 14:11:00 +0300 Message-ID: <55C09DC4.4070108@cogentembedded.com> References: <1438682145-25986-1-git-send-email-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1438682145-25986-1-git-send-email-jasowang@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Jason Wang , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: mst@redhat.com List-Id: virtualization@lists.linuxfoundation.org Hello. On 8/4/2015 12:55 PM, Jason Wang wrote: > virtio declares support for NETIF_F_FRAGLIST, but assumes > that there are at most MAX_SKB_FRAGS + 2 fragments which isn't > always true with a fraglist. > A longer fraglist in the skb will make the call to skb_to_sgvec overflow > the sg array, leading to memory corruption. > Drop NETIF_F_FRAGLIST so we only get what we can handle. > Cc: Michael S. Tsirkin > Signed-off-by: Jason Wang > --- > The patch is needed for stable. > --- > drivers/net/virtio_net.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 7fbca37..2347a73 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -1756,9 +1756,9 @@ static int virtnet_probe(struct virtio_device *vdev) > /* Do we support "hardware" checksums? */ > if (virtio_has_feature(vdev, VIRTIO_NET_F_CSUM)) { > /* This opens up the world of extra features. */ > - dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; > + dev->hw_features |= NETIF_F_HW_CSUM|NETIF_F_SG; > if (csum) > - dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG|NETIF_F_FRAGLIST; > + dev->features |= NETIF_F_HW_CSUM|NETIF_F_SG; I'd have added spaces around | to match the style seen below. > if (virtio_has_feature(vdev, VIRTIO_NET_F_GSO)) { > dev->hw_features |= NETIF_F_TSO | NETIF_F_UFO MBR, Sergei