diff --git a/server/modules/filter/hint/hintparser.c b/server/modules/filter/hint/hintparser.c
index df0888508..0d0e47dcb 100644
--- a/server/modules/filter/hint/hintparser.c
+++ b/server/modules/filter/hint/hintparser.c
@@ -435,7 +435,7 @@ HINT_MODE	mode = HM_EXECUTE;
 		token_free(tok);
 	} /*< while */
 	
-	if (tok->token == TOK_EOL)
+	if ( tok && tok->token == TOK_EOL)
         {
                 token_free(tok);
         }
diff --git a/server/modules/filter/topfilter.c b/server/modules/filter/topfilter.c
index e4c16b2ba..eaf471910 100644
--- a/server/modules/filter/topfilter.c
+++ b/server/modules/filter/topfilter.c
@@ -314,10 +314,10 @@ char		*remote, *user;
 		else
 			my_session->userName = NULL;
 		my_session->active = 1;
-		if (my_instance->source && strcmp(my_session->clientHost,
+		if (my_instance->source && my_session->clientHost && strcmp(my_session->clientHost,
 							my_instance->source))
 			my_session->active = 0;
-		if (my_instance->user && strcmp(my_session->userName,
+		if (my_instance->user && my_session->userName && strcmp(my_session->userName,
 							my_instance->user))
 			my_session->active = 0;
 
diff --git a/server/modules/routing/readwritesplit/readwritesplit.c b/server/modules/routing/readwritesplit/readwritesplit.c
index 6b475a4e9..eca2a5615 100644
--- a/server/modules/routing/readwritesplit/readwritesplit.c
+++ b/server/modules/routing/readwritesplit/readwritesplit.c
@@ -1540,12 +1540,12 @@ skygw_query_type_t is_read_tmp_table(
 	}
     }
 
-	for(i = 0; i<tsize;i++)
-		{
-			free(tbl[i]);
-		}
-
+	
 	if(tbl != NULL){
+		for(i = 0; i<tsize;i++)
+			{
+				free(tbl[i]);
+			}
 		free(tbl);
 	}