LDAPworld P4: SLAPD Crash when Schema Checking

servers/slapd/schema.c

@@ -111,14 +111,16 @@ oc_check_allowed( char *type, struct berval **ocl )
 		/* if we know about the oc */
 		if ( (oc = oc_find( ocl[i]->bv_val )) != NULL ) {
 			/* does it require the type? */
-			for ( j = 0; oc->oc_required[j] != NULL; j++ ) {
+			for ( j = 0; oc->oc_required != NULL && 
+				oc->oc_required[j] != NULL; j++ ) {
 				if ( strcasecmp( oc->oc_required[j], type )
 				    == 0 ) {
 					return( 0 );
 				}
 			}
 			/* does it allow the type? */
-			for ( j = 0; oc->oc_allowed[j] != NULL; j++ ) {
+			for ( j = 0; oc->oc_allowed != NULL && 
+				oc->oc_allowed[j] != NULL; j++ ) {
 				if ( strcasecmp( oc->oc_allowed[j], type )
 				    == 0 || strcmp( oc->oc_allowed[j], "*" )
 				    == 0 )