fib_trie: handle empty tree

This fixes possible problems when trie_firstleaf() returns NULL
to trie_leafindex().

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 4 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index f5fba3f71c0..2d895274b7f 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1762,11 +1762,9 @@ static struct leaf *trie_leafindex(struct trie *t, int index)
 {
         struct leaf *l = trie_firstleaf(t);
 
-        while (index-- > 0) {
+        while (l && index-- > 0)
                 l = trie_nextleaf(l);
-                if (!l)
-                        break;
-        }
+
         return l;
 }