Re: [PATCH net 7/7] rxrpc: Use skb_unshare() rather than skb_cow_data()

[David Howells]

Hillf Danton <hdanton@xxxxxxxx> wrote:

> > +		/* Unshare the packet so that it can be modified for in-place
> > +		 * decryption.
> > +		 */
> > +		if (sp->hdr.securityIndex != 0) {
> > +			struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
> > +			if (!nskb) {
> > +				rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
> > +				goto out;
> > +			}
> > +
> > +			if (nskb != skb) {
> > +				rxrpc_eaten_skb(skb, rxrpc_skb_received);
> > +				rxrpc_new_skb(skb, rxrpc_skb_unshared);
> > +				skb = nskb;
> > +				sp = rxrpc_skb(skb);
> > +			}
> > +		}
> 
> Unsharing skb makes it perilous to take a peep at it afterwards.

Ah, good point.  rxrpc_new_skb() should be after the assignment.

David