On Linux systems, sudo parses the /proc/[pid]/stat file to determine the device number of the process’s tty (field 7). The fields in the file are space-delimited, but it is possible for the command name (field 2) to include white space (including newline), which sudo does not account for. A user with sudo privileges can cause sudo to use a device number of the user’s choosing by creating a symbolic link from the sudo binary to a name that contains a space, followed by a number.