From 3c9e9f7320f0138497ef7879c0903246746e0ed3 Mon Sep 17 00:00:00 2001
From: Alexander Duyck <alexander.h.duyck@redhat.com>
Date: Thu, 12 Mar 2015 14:46:23 -0700
Subject: [PATCH] fib_trie: Avoid NULL pointer if local table is not allocated

The function fib_unmerge assumed the local table had already been
allocated.  If that is not the case however when custom rules are applied
then this can result in a NULL pointer dereference.

In order to prevent this we must check the value of the local table pointer
and if it is NULL simply return 0 as there is no local table to separate
from the main.

Fixes: 0ddcf43d5 ("ipv4: FIB Local/MAIN table collapse")
Reported-by: Madhu Challa <challa@noironetworks.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
Reading git-format-patch failed