On Mon, 2011-10-03 at 21:04 +0200, Michael S. Tsirkin wrote: > On Wed, Sep 28, 2011 at 05:40:54PM +0300, Sasha Levin wrote: > > This patch verifies that the length of a buffer stored in a linked list > > of pages is small enough to fit into a skb. > > > > If the size is larger than a max size of a skb, it means that we shouldn't > > go ahead building skbs anyway since we won't be able to send the buffer as > > the user requested. > > > > Cc: Rusty Russell <[email protected]> > > Cc: "Michael S. Tsirkin" <[email protected]> > > Cc: [email protected] > > Cc: [email protected] > > Cc: [email protected] > > Signed-off-by: Sasha Levin <[email protected]> > > --- > > drivers/net/virtio_net.c | 13 +++++++++++++ > > 1 files changed, 13 insertions(+), 0 deletions(-) > > > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > > index 0c7321c..bde0dec 100644 > > --- a/drivers/net/virtio_net.c > > +++ b/drivers/net/virtio_net.c > > @@ -195,6 +195,19 @@ static struct sk_buff *page_to_skb(struct virtnet_info > > *vi, > > len -= copy; > > offset += copy; > > > > + /* > > + * Verify that we can indeed put this data into a skb. > > + * This is here to handle cases when the device erroneously > > + * tries to receive more than is possible. This is usually > > + * the case of a broken device. > > + */ > > + if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { > > + if (net_ratelimit()) > > + pr_debug("%s: too much data\n", skb->dev->name); > > + dev_kfree_skb(skb); > > + return NULL; > > + } > > + > > BTW, receive_mergeable does > pr_debug("%s: packet too long\n", skb->dev->name); > skb->dev->stats.rx_length_errors++; > > which makes sense.
Do you think we should increase rx_length_errors here as well? -- Sasha. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
