差分

$ find /bin -perm +a+s -exec ls -l {} \;

-rwsr-xr-x 1 root root 26252 Mar 3 2012 /bin/fusermount

-rwsr-xr-x 1 root root 31116 Sep 13 2012 /bin/su

-rwsr-xr-x 1 root root 67720 Mar 30 2012 /bin/umount