--- cc768caa38f54b86f48ec92310ed93e3b1fcf998
+++ a0f7b99aee8be4b8d3aab15c03f7af6ecfb5005e
@@ -1243,14 +1243,10 @@ static void do_action(int action, struct
 		 * note that bcs may be NULL if no B channel is free
 		 */
 		at_state2->ConState = 700;
-		kfree(at_state2->str_var[STR_NMBR]);
-		at_state2->str_var[STR_NMBR] = NULL;
-		kfree(at_state2->str_var[STR_ZCPN]);
-		at_state2->str_var[STR_ZCPN] = NULL;
-		kfree(at_state2->str_var[STR_ZBC]);
-		at_state2->str_var[STR_ZBC] = NULL;
-		kfree(at_state2->str_var[STR_ZHLC]);
-		at_state2->str_var[STR_ZHLC] = NULL;
+		for (i = 0; i < STR_NUM; ++i) {
+			kfree(at_state2->str_var[i]);
+			at_state2->str_var[i] = NULL;
+		}
 		at_state2->int_var[VAR_ZCTP] = -1;
 
 		spin_lock_irqsave(&cs->lock, flags);