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.
Acked-by: Michael S. Tsirkin mst@redhat.com Fixes: a2fb4bc4e2a6a ("net: implement virtio helpers to handle UDP GSO tunneling") Cc: stable@vger.kernel.org Signed-off-by: Jason Wang jasowang@redhat.com --- 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);
On Wed, 22 Oct 2025 11:44:21 +0800, Jason Wang jasowang@redhat.com 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.
Reviewed-by: Xuan Zhuo xuanzhuo@linux.alibaba.com
Acked-by: Michael S. Tsirkin mst@redhat.com Fixes: a2fb4bc4e2a6a ("net: implement virtio helpers to handle UDP GSO tunneling") Cc: stable@vger.kernel.org Signed-off-by: Jason Wang jasowang@redhat.com
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
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