virtio_net: Do not clear memory for struct virtio_net_hdr twice.

virtio_net_hdr_from_skb() clears the memory for the header, so there
is no point for the callers to do the same.
Signed-off-by: Jarno Rajahalme <jarno@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/tun.c

@@ -1360,8 +1360,7 @@ static ssize_t tun_put_user(struct tun_struct *tun,
 	}
 
 	if (vnet_hdr_sz) {
-		struct virtio_net_hdr gso = { 0 }; /* no info leak */
-		int ret;
+		struct virtio_net_hdr gso;
 
 		if (iov_iter_count(iter) < vnet_hdr_sz)
 			return -EINVAL;

include/linux/virtio_net.h

@@ -58,7 +58,7 @@ static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb,
 					  struct virtio_net_hdr *hdr,
 					  bool little_endian)
 {
-	memset(hdr, 0, sizeof(*hdr));
+	memset(hdr, 0, sizeof(*hdr));   /* no info leak */
 
 	if (skb_is_gso(skb)) {
 		struct skb_shared_info *sinfo = skb_shinfo(skb);

net/packet/af_packet.c

@@ -1970,8 +1970,6 @@ static unsigned int run_filter(struct sk_buff *skb,
 static int __packet_rcv_vnet(const struct sk_buff *skb,
 			     struct virtio_net_hdr *vnet_hdr)
 {
-	*vnet_hdr = (const struct virtio_net_hdr) { 0 };
-
 	if (virtio_net_hdr_from_skb(skb, vnet_hdr, vio_le()))
 		BUG();