kernel: add remaining kernel patch accidentally left out of r47963

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

Backport of r47966

git-svn-id: svn://svn.openwrt.org/openwrt/branches/chaos_calmer@47967 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/generic/patches-3.18/081-06-ppp-don-t-set-sk_state-to-PPPOX_ZOMBIE-in-pppoe_disc.patch

@@ -0,0 +1,45 @@
+From: Guillaume Nault <g.nault@alphalink.fr>
+Date: Thu, 19 Nov 2015 12:52:56 +0100
+Subject: [PATCH] ppp: don't set sk_state to PPPOX_ZOMBIE in pppoe_disc_rcv()
+
+Since 287f3a943fef ("pppoe: Use workqueue to die properly when a PADT
+is received"), pppoe_disc_rcv() disconnects the socket by scheduling
+pppoe_unbind_sock_work(). This is enough to stop socket transmission
+and makes the PPPOX_ZOMBIE state uncessary.
+
+Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/drivers/net/ppp/pppoe.c
++++ b/drivers/net/ppp/pppoe.c
+@@ -500,27 +500,9 @@ static int pppoe_disc_rcv(struct sk_buff
+ 
+ 	pn = pppoe_pernet(dev_net(dev));
+ 	po = get_item(pn, ph->sid, eth_hdr(skb)->h_source, dev->ifindex);
+-	if (po) {
+-		struct sock *sk = sk_pppox(po);
+-
+-		bh_lock_sock(sk);
+-
+-		/* If the user has locked the socket, just ignore
+-		 * the packet.  With the way two rcv protocols hook into
+-		 * one socket family type, we cannot (easily) distinguish
+-		 * what kind of SKB it is during backlog rcv.
+-		 */
+-		if (sock_owned_by_user(sk) == 0) {
+-			/* We're no longer connect at the PPPOE layer,
+-			 * and must wait for ppp channel to disconnect us.
+-			 */
+-			sk->sk_state = PPPOX_ZOMBIE;
+-		}
+-
+-		bh_unlock_sock(sk);
++	if (po)
+ 		if (!schedule_work(&po->proto.pppoe.padt_work))
+-			sock_put(sk);
+-	}
++			sock_put(sk_pppox(po));
+ 
+ abort:
+ 	kfree_skb(skb);