Fix bug 5419: memory leak in ads_do_search_all_args() when enumerating 1000s of entries

The ads_do_search_all_args() function attempts to string together several
LDAPMessage structures, returned across several paged ldap requests, into a
single LDAPMessage structure.  It does this by pulling entries off the second
LDAPMessage structure and appending them to the first via the OpenLDAP specific
ldap_add_result_entry() call.

The problem with this approach is it skips non-entry messages such as the
result, and controls.  These messages are leaked.

The short term solution as suggested by Volker is to replace the ads_*_entry()
calls with ads_*_message() calls so we don't leak any messages.

This fixes the leak but doesn't remove the dependence on the OpenLDAP specific
implementation of ldap_add_result_entry().
(This used to be commit f1a5405409c396df394611e2a234522572d2860a)

1 files changed, 24 insertions, 2 deletions

diff --git a/source3/libads/ldap.c b/source3/libads/ldap.c
index b0f27b598b..9321302151 100644
--- a/source3/libads/ldap.c
+++ b/source3/libads/ldap.c
@@ -870,8 +870,8 @@ static ADS_STATUS ads_do_paged_search(ADS_STRUCT *ads, const char *bind_path,
 
 		/* this relies on the way that ldap_add_result_entry() works internally. I hope
 		   that this works on all ldap libs, but I have only tested with openldap */
-		for (msg = ads_first_entry(ads, res2); msg; msg = next) {
-			next = ads_next_entry(ads, msg);
+		for (msg = ads_first_message(ads, res2); msg; msg = next) {
+			next = ads_next_message(ads, msg);
 			ldap_add_result_entry((LDAPMessage **)res, msg);
 		}
 		/* note that we do not free res2, as the memory is now
@@ -2091,6 +2091,28 @@ int ads_count_replies(ADS_STRUCT *ads, void *res)
 }
 
 /**
+ * pull the first message from a ADS result
+ * @param ads connection to ads server
+ * @param res Results of search
+ * @return first message from result
+ **/
+ LDAPMessage *ads_first_message(ADS_STRUCT *ads, LDAPMessage *res)
+{
+	return ldap_first_message(ads->ldap.ld, res);
+}
+
+/**
+ * pull the next message from a ADS result
+ * @param ads connection to ads server
+ * @param res Results of search
+ * @return next message from result
+ **/
+ LDAPMessage *ads_next_message(ADS_STRUCT *ads, LDAPMessage *res)
+{
+	return ldap_next_message(ads->ldap.ld, res);
+}
+
+/**
  * pull a single string from a ADS result
  * @param ads connection to ads server
  * @param mem_ctx TALLOC_CTX to use for allocating result string