From: Kostya B <redacted>
Date: Thu, 20 Nov 2008 11:59:28 +0000

Perhaps we should take a closer look on pskb_expand_head()

And add 

+skb->truesize = size + sizeof(struct sk_buff);

You can't.  If a socket is attached to the skb it's buffer
accounting will get corrupted if you modify skb->truesize.

This has been explained a thousand times on this list.