diff --git a/drivers/net/tun_vnet.h b/drivers/net/tun_vnet.h
index fd7411c4447f..58b9ac7a5fc4 100644
--- a/drivers/net/tun_vnet.h
+++ b/drivers/net/tun_vnet.h
@@ -143,7 +143,8 @@ static inline int tun_vnet_hdr_put(int sz, struct iov_iter *iter,
 	if (unlikely(copy_to_iter(hdr, sizeof(*hdr), iter) != sizeof(*hdr)))
 		return -EFAULT;
 
-	iov_iter_advance(iter, sz - sizeof(*hdr));
+	if (iov_iter_zero(sz - sizeof(*hdr), iter) != sz - sizeof(*hdr))
+		return -EFAULT;
 
 	return 0;
 }