The (1) it87 and (2) via686a drivers in I2C for Linux 2.6.x before 2.6.11.8, and 2.6.12 before 2.6.12-rc2, create the sysfs "alarms" file with write permissions, which allows local users to cause a denial of service (CPU consumption) by attempting to write to the file, which does not have an associated store function.