appletalk: Fix skb leak when ipddp interface is not loaded (CVE-2009-2903)

appletalk: Fix skb leak when ipddp interface is not loaded (CVE-2009-2903)

commit ffcfb8db540ff879c2a85bf7e404954281443414 upstream

appletalk: Fix skb leak when ipddp interface is not loaded

[ backport to 2.6.27 : Chuck Ebbert <cebbert@redhat.com ]

And also do a better job of returning proper NET_{RX,XMIT}_ values.

Based on a patch and suggestions by Mark Smith.

This fixes CVE-2009-2903

Reported-by: Mark Smith <lk-netdev@lk-netdev.nosense.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>