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    SubjectRe: [PATCH 2/2] virtio-net: Prevent NULL dereference
    On Mon, Sep 26, 2011 at 08:41:09PM +0300, Sasha Levin wrote:
    > This patch prevents a NULL dereference when the user has passed a length
    > longer than an actual buffer to virtio-net.
    >
    > Cc: Rusty Russell <rusty@rustcorp.com.au>
    > Cc: "Michael S. Tsirkin" <mst@redhat.com>
    > Cc: virtualization@lists.linux-foundation.org
    > Cc: netdev@vger.kernel.org
    > Cc: kvm@vger.kernel.org
    > Signed-off-by: Sasha Levin <levinsasha928@gmail.com>

    Hmm, another protection against a buggy device, right?
    No problem with that, but let's discard the packet
    and print a disgnostic, so that the user can discover
    what happened.

    > ---
    > drivers/net/virtio_net.c | 2 +-
    > 1 files changed, 1 insertions(+), 1 deletions(-)
    >
    > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
    > index 64e0717..8d32c1e 100644
    > --- a/drivers/net/virtio_net.c
    > +++ b/drivers/net/virtio_net.c
    > @@ -198,7 +198,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi,
    > len -= copy;
    > offset += copy;
    >
    > - while (len) {
    > + while (len && page) {
    > set_skb_frag(skb, page, offset, &len);
    > page = (struct page *)page->private;
    > offset = 0;
    > --
    > 1.7.6.1


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