From da318fa5f147e229069b13c0479fdf81ccc28213 Mon Sep 17 00:00:00 2001
From: Mark Reynolds <mreynolds@redhat.com>
Date: Jul 14 2014 20:22:14 +0000
Subject: Ticket 47858 - Internal searches using OP_FLAG_REVERSE_CANDIDATE_ORDER can crash the server


Bug Description:  If an internal search uses OP_FLAG_REVERSE_CANDIDATE_ORDER, and
                  the search fails tro find any candidates the server will crash.

Fix Description:  Make sure we do not dereference a NULL sr_candidates pointer in
                  ldbm_search().

https://fedorahosted.org/389/ticket/47858

Reviewed by: rmeggins(Thanks!)

(cherry picked from commit e6cee31aa2beb6496df86490776f1f93d3a8348b)

---

diff --git a/ldap/servers/slapd/back-ldbm/ldbm_search.c b/ldap/servers/slapd/back-ldbm/ldbm_search.c
index 6dff1f5..f1375a5 100644
--- a/ldap/servers/slapd/back-ldbm/ldbm_search.c
+++ b/ldap/servers/slapd/back-ldbm/ldbm_search.c
@@ -1450,7 +1450,7 @@ ldbm_back_next_search_entry_ext( Slapi_PBlock *pb, int use_extension )
          * search can enter this function multiple times, we need to keep track
          * of our state, and only initialize sr_current once.
          */
-        if(!op->o_reverse_search_state){
+        if(!op->o_reverse_search_state && sr->sr_candidates){
             sr->sr_current = sr->sr_candidates->b_nids;
             op->o_reverse_search_state = REV_STARTED;
         }