systemctl: fix bad memory access when processing PIDs on the "systemctl status" command line

src/systemctl/systemctl.c

@@ -3678,6 +3678,7 @@ static int get_unit_dbus_path_by_pid(
 
         _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
         _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        char *u;
         int r;
 
         r = sd_bus_call_method(
@@ -3694,10 +3695,15 @@ static int get_unit_dbus_path_by_pid(
                 return r;
         }
 
-        r = sd_bus_message_read(reply, "o", unit);
+        r = sd_bus_message_read(reply, "o", &u);
         if (r < 0)
                 return bus_log_parse_error(r);
 
+        u = strdup(u);
+        if (!u)
+                return log_oom();
+
+        *unit = u;
         return 0;
 }
 
@@ -3880,8 +3886,10 @@ static int show(sd_bus *bus, char **args) {
                         } else {
                                 /* Interpret as PID */
                                 r = get_unit_dbus_path_by_pid(bus, id, &unit);
-                                if (r < 0)
+                                if (r < 0) {
                                         ret = r;
+                                        continue;
+                                }
                         }
 
                         show_one(args[0], bus, unit, show_properties, &new_line, &ellipsized);