kernel: add a patch to fix crashes on pppoe disconnect/reconnect

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

Backport of r47026

git-svn-id: svn://svn.openwrt.org/openwrt/branches/chaos_calmer@47027 3c298f89-4303-0410-b956-a3cf2f4a3e73

target/linux/generic/patches-3.18/101-pppoe-fix-disconnect-crash.patch

@@ -0,0 +1,16 @@
+Fix crash with actions performed on the underlying interface (MAC address,
+MTU or link state update). This triggers pppoe_flush_dev(), which cleans up
+the device without announcing it in sk->sk_state.
+
+Patch by Guillaume Nault (pulled from netdev@vger)
+
+--- a/drivers/net/ppp/pppoe.c
++++ b/drivers/net/ppp/pppoe.c
+@@ -313,7 +313,6 @@ static void pppoe_flush_dev(struct net_d
+ 			if (po->pppoe_dev == dev &&
+ 			    sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND | PPPOX_ZOMBIE)) {
+ 				pppox_unbind_sock(sk);
+-				sk->sk_state = PPPOX_ZOMBIE;
+ 				sk->sk_state_change(sk);
+ 				po->pppoe_dev = NULL;
+ 				dev_put(dev);

target/linux/generic/patches-3.18/650-pppoe_header_pad.patch

@@ -1,6 +1,6 @@
 --- a/drivers/net/ppp/pppoe.c
 +++ b/drivers/net/ppp/pppoe.c
-@@ -869,7 +869,7 @@ static int pppoe_sendmsg(struct kiocb *i
+@@ -868,7 +868,7 @@ static int pppoe_sendmsg(struct kiocb *i
  		goto end;
  
  
@@ -9,7 +9,7 @@
  			   0, GFP_KERNEL);
  	if (!skb) {
  		error = -ENOMEM;
-@@ -877,7 +877,7 @@ static int pppoe_sendmsg(struct kiocb *i
+@@ -876,7 +876,7 @@ static int pppoe_sendmsg(struct kiocb *i
  	}
  
  	/* Reserve space for headers. */