[PATCH net V2] virtio-net: zero unused hash fields
From: Jason Wang
Date: Tue Oct 21 2025 - 23:44:37 EST
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@xxxxxxxxxx>
Fixes: a2fb4bc4e2a6a ("net: implement virtio helpers to handle UDP GSO tunneling")
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
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