From mboxrd@z Thu Jan  1 00:00:00 1970
From: Pablo Neira Ayuso <pablo@netfilter.org>
Subject: Re: [PATCHv2 net-next] netlink: allow large data transfers from
 user-space
Date: Mon, 3 Jun 2013 19:41:38 +0200
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Cc: netdev@vger.kernel.org, davem@davemloft.net, kaber@trash.net
To: Eric Dumazet <eric.dumazet@gmail.com>
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Hi Eric!

On Mon, Jun 03, 2013 at 10:12:39AM -0700, Eric Dumazet wrote:
> On Mon, 2013-06-03 at 18:39 +0200, Pablo Neira Ayuso wrote:
> 
> > +	if (is_vmalloc_addr(skb->head)) {
> > +		vfree(skb->head);
> > +		skb->data = NULL;
> > +	}
> >  
> 
> You probably meant :
> 
> 	skb->head = NULL;
> 
> Now, cross our fingers we do not skb_orphan() these skb too early :)

skb_release_all checks for skb->data != NULL to release skb->head as
it would have been allocated via kmalloc. This didn't look very
intuitive to me when I hit a panic while testing my patch either.

So unless I'm missing anything, that skb->data is OK with the existing
code we have.

Regards.