729738 - net-snmp dumps core in netsnmp_oid_find_prefix

commit f9304c83f76202db0e684269ca1af32e43cd9db4
Author: Jan Safranek <jsafranek@users.sourceforge.net>
Date:   Tue Feb 7 14:53:44 2012 +0100

    CHANGES: PATCH 1633670: fixed snmpd crashing when an AgentX subagent disconnect in the middle of processing of a request.
    
    I fixed also the memory leak reported in the tracker comments.

diff --git a/agent/mibgroup/agentx/master.c b/agent/mibgroup/agentx/master.c
index c42a42a..baeebaf 100644
--- a/agent/mibgroup/agentx/master.c
+++ b/agent/mibgroup/agentx/master.c
@@ -219,6 +219,9 @@ agentx_got_response(int operation,
     if (!cache) {
         DEBUGMSGTL(("agentx/master", "response too late on session %8p\n",
                     session));
+        /* response is too late, free the cache */
+        if (magic)
+            netsnmp_free_delegated_cache((netsnmp_delegated_cache*) magic);
         return 0;
     }
     requests = cache->requests;
@@ -606,6 +609,8 @@ agentx_master_handler(netsnmp_mib_handler *handler,
     result = snmp_async_send(ax_session, pdu, agentx_got_response, cb_data);
     if (result == 0) {
         snmp_free_pdu(pdu);
+        if (cb_data)
+            netsnmp_free_delegated_cache((netsnmp_delegated_cache*) cb_data);
     }
 
     return SNMP_ERR_NOERROR;
diff --git a/agent/mibgroup/agentx/master_admin.c b/agent/mibgroup/agentx/master_admin.c
index f16f392..b84b85e 100644
--- a/agent/mibgroup/agentx/master_admin.c
+++ b/agent/mibgroup/agentx/master_admin.c
@@ -133,11 +133,16 @@ close_agentx_session(netsnmp_session * session, int sessid)
          * requests, so that the delegated request will be completed and
          * further requests can be processed
          */
-        netsnmp_remove_delegated_requests_for_session(session);
+	while (netsnmp_remove_delegated_requests_for_session(session)) {
+		DEBUGMSGTL(("agentx/master", "Continue removing delegated reqests\n"));
+	}
+
         if (session->subsession != NULL) {
             netsnmp_session *subsession = session->subsession;
             for(; subsession; subsession = subsession->next) {
-                netsnmp_remove_delegated_requests_for_session(subsession);
+                while (netsnmp_remove_delegated_requests_for_session(subsession)) {
+			DEBUGMSGTL(("agentx/master", "Continue removing delegated subsession reqests\n"));
+		}
             }
         }