title: sk_buff struct functions and memory leak
body: <p>I'm developing some network driver for linux kernel. It is working fine, but it seems that there are memory leaks. I think that two of functions I use are suspected:</p>
  
  <pre><code>skb2 = skb_realloc_headroom(skb, size);
  
  skb2 = skb_copy_expand(skb, skb_headroom(skb), size, GFP_ATOMIC);
  </code></pre>
  
  <p>My question is - do those functions make a copy of skb as skb2 and I can safely free skb or not? Or maybe skb2 is just expanded skb and I cannot free them?</p>