On Tue, Oct 21, 2025 at 12:01:55PM +0800, Jason Wang wrote:
> When GSO tunnel is negotiated virtio_net_hdr_tnl_from_skb() tries to
> initialize the tunnel metadata but forget to zero unused rxhash
> fields. This may leak information to another side. Fixing this by
> zeroing the unused hash fields.
>
> Fixes: a2fb4bc4e2a6a ("net: implement virtio helpers to handle UDP GSO
> tunneling")x
> Cc: <[email protected]>
> Signed-off-by: Jason Wang <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
> ---
> include/linux/virtio_net.h | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h
> index 20e0584db1dd..4d1780848d0e 100644
> --- a/include/linux/virtio_net.h
> +++ b/include/linux/virtio_net.h
> @@ -401,6 +401,10 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb,
> if (!tnl_hdr_negotiated)
> return -EINVAL;
>
> + vhdr->hash_hdr.hash_value = 0;
> + vhdr->hash_hdr.hash_report = 0;
> + vhdr->hash_hdr.padding = 0;
> +
> /* Let the basic parsing deal with plain GSO features. */
> skb_shinfo(skb)->gso_type &= ~tnl_gso_type;
> ret = virtio_net_hdr_from_skb(skb, hdr, true, false, vlan_hlen);
> --
> 2.42.0
