SUDO 퍼미션 오류.sudo: can't open /etc/sudoers: Permission denied

제가어제 sudo nautilus가 먹통이되서 걍 etc폴더를 통채로 권한을 777로 바꾸고난다음부터
이런 현상이 벌어졌는데요…
sudo 440으로다시돌라고해서 (터미널에서도) 리커버리모드가서 바꿧는데도 퍼미션 거부가뜨네요…
아래는 터미널 내용입니다.
구글/네이버에쳐서 대충 봤는데 아직 해결을 못하고있어요. 도와주세요 제발…

root@ubuntu:/# sudo
sudo: unable to resolve host ubuntu
sudo: can’t open /etc/sudoers: Permission denied

[b:262vhsr7]root@ubuntu:/# ls -al /etc/sudoers[/b:262vhsr7]
-r–r----- 1 root root 609 2011-04-18 03:02 /etc/sudoer

[b:262vhsr7]root@ubuntu:/# ls -al /usr/bin/sudo[/b:262vhsr7]
—s–x–x 1 root root 127668 2011-01-20 03:01 /usr/bin/sudo

[b:262vhsr7]root@ubuntu:/# ls -al /[/b:262vhsr7]
합계 116
drwxr-xr-x 23 root root 4096 2011-08-23 18:00 .
drwxr-xr-x 23 root root 4096 2011-08-23 18:00 …
drwxr-xr-x 2 root root 4096 2011-07-30 11:46 bin
drwxr-xr-x 3 root root 4096 2011-08-15 19:11 boot
drwxr-xr-x 3 root root 4096 2011-08-23 17:39 cdrom
drwxr-xr-x 17 root root 3840 2011-08-24 17:26 dev
dr–r----- 145 root root 12288 2011-08-24 16:58 etc
drwxr-xr-x 4 root root 4096 2011-04-30 14:09 home
lrwxrwxrwx 1 root root 28 2011-08-15 19:11 initrd.img -> boot/initrd.img-2.6.31-11-rt
lrwxrwxrwx 1 root root 33 2011-07-20 16:47 initrd.img.old -> boot/initrd.img-2.6.32-33-generic
drwxr-xr-x 21 root root 12288 2011-08-07 19:01 lib
drwx------ 2 root root 16384 2011-04-18 02:51 lost+found
drwxr-xr-x 3 root root 4096 2011-08-24 16:55 media
drwxr-xr-x 2 root root 4096 2010-04-23 19:11 mnt
drwxr-xr-x 3 root root 4096 2011-05-11 16:09 opt
drwxr-xr-x 2 root root 4096 2010-04-23 19:11 proc
drwxr-xr-x 6 root root 4096 2011-08-24 17:00 root
drwxr-xr-x 2 root root 4096 2011-08-16 19:51 sbin
drwxr-xr-x 2 root root 4096 2009-12-06 06:55 selinux
drwxr-xr-x 3 root root 4096 2011-04-18 00:19 src
drwxr-xr-x 4 root root 4096 2011-04-17 19:01 srv
drwxr-xr-x 2 root root 4096 2010-03-30 16:17 sys
drwxrwxrwt 4 root root 4096 2011-08-24 17:00 tmp
lrwxrwxrwx 1 root root 4 2011-05-20 02:37 tmp에 링크 -> /tmp
drwxr-xr-x 11 root root 4096 2011-04-17 18:37 usr
drwxr-xr-x 16 root root 4096 2011-04-17 19:07 var
lrwxrwxrwx 1 root root 25 2011-08-15 19:11 vmlinuz -> boot/vmlinuz-2.6.31-11-rt
lrwxrwxrwx 1 root root 30 2011-07-20 16:47 vmlinuz.old -> boot/vmlinuz-2.6.32-33-generic
root@ubuntu:/#

[b:262vhsr7]root@ubuntu:/# ls -la /etc[/b:262vhsr7]
합계 1224
dr–r----- 145 root root 12288 2011-08-24 16:58 .
drwxr-xr-x 23 root root 4096 2011-08-23 18:00 …
dr–r----- 3 root root 4096 2011-08-13 17:49 .java
-r–r----- 1 root root 0 2011-02-11 22:06 .pwd.lock
dr–r----- 5 root root 4096 2011-02-11 22:10 ConsoleKit
dr–r----- 5 root root 4096 2011-05-29 09:06 NetworkManager
dr–r----- 2 root root 4096 2009-12-05 09:45 ODBCDataSources
dr–r----- 10 root root 4096 2011-04-17 20:20 X11
dr–r----- 3 root root 4096 2011-04-17 20:19 acpi
-r–r----- 1 root root 2981 2011-02-11 22:06 adduser.conf
dr–r----- 2 root root 12288 2011-08-23 18:16 alternatives
-r–r----- 1 root root 395 2010-03-05 11:29 anacrontab
dr–r----- 7 root root 4096 2011-05-05 18:07 apache2
dr–r----- 6 root root 4096 2011-02-11 22:13 apm
dr–r----- 3 root root 4096 2011-02-11 22:20 apparmor
dr–r----- 7 root root 4096 2011-08-20 10:59 apparmor.d
dr–r----- 4 root root 4096 2011-02-11 22:23 apport
dr–r----- 6 root root 4096 2011-08-13 17:44 apt
-r–r----- 1 root daemon 144 2011-01-15 09:44 at.deny
lrwxrwxrwx 1 root root 26 2011-04-17 20:19 ati -> /etc/alternatives/ati_conf
dr–r----- 3 root root 4096 2011-04-17 20:14 avahi
-r–r----- 1 root root 1939 2010-04-19 10:51 bash.bashrc
-r–r----- 1 root root 51761 2010-04-14 22:32 bash_completion
dr–r----- 2 root root 4096 2011-06-19 10:13 bash_completion.d
-r–r----- 1 root root 344 2010-04-22 23:04 bindresvport.blacklist
-r–r----- 1 root root 321 2010-03-23 02:50 blkid.conf
lrwxrwxrwx 1 root root 15 2011-04-18 02:51 blkid.tab -> /dev/.blkid.tab
dr–r----- 2 root root 4096 2011-02-11 22:20 bluetooth
-r–r----- 1 root root 7135 2010-08-27 23:57 bogofilter.cf
dr–r----- 2 root root 4096 2011-02-11 22:19 bonobo-activation
-r–r----- 1 root root 33 2011-02-11 22:22 brlapi.key
dr–r----- 2 root root 12288 2011-02-11 22:22 brltty
dr–r----- 2 root root 4096 2011-02-11 22:22 byobu
dr–r----- 3 root root 4096 2011-02-11 22:06 ca-certificates
-r–r----- 1 root root 6332 2011-02-11 22:08 ca-certificates.conf
dr–r----- 2 root root 4096 2009-11-11 01:12 calendar
dr–r-S— 2 root dip 4096 2011-02-11 22:20 chatscripts
dr–r----- 2 root root 4096 2011-02-11 22:22 checkbox.d
dr–r----- 2 root root 4096 2011-02-11 22:20 compizconfig
dr–r----- 2 root root 4096 2011-02-11 22:23 computer-janitor.d
dr–r----- 2 root root 4096 2011-02-11 22:08 console-setup
dr–r----- 4 couchdb couchdb 4096 2011-02-11 22:21 couchdb
dr–r----- 2 root root 4096 2011-05-05 11:44 cron.d
dr–r----- 2 root root 4096 2011-08-07 19:02 cron.daily
dr–r----- 2 root root 4096 2011-02-11 22:07 cron.hourly
dr–r----- 2 root root 4096 2011-02-11 22:20 cron.monthly
dr–r----- 2 root root 4096 2011-04-17 18:39 cron.weekly
-r–r----- 1 root root 724 2010-04-15 08:29 crontab
-r–r----- 1 root root 54 2011-02-11 22:24 crypttab
dr–r----- 4 root lp 4096 2011-02-11 22:19 cups
-r–r----- 1 root root 89 2011-04-17 18:39 cvs-cron.conf
-r–r----- 1 root root 126 2011-04-17 18:39 cvs-pserver.conf
dr–r----- 2 root root 4096 2011-04-20 18:41 dbconfig-common
dr–r----- 5 root root 4096 2011-07-30 11:47 dbus-1
-r–r----- 1 root root 2969 2010-04-09 23:33 debconf.conf
-r–r----- 1 root root 12 2010-04-23 18:45 debian_version
dr–r----- 2 root root 4096 2011-08-23 18:16 default
dr–r----- 4 root root 4096 2011-02-11 22:19 defoma
-r–r----- 1 root root 600 2010-01-27 19:26 deluser.conf
dr–r----- 2 root root 4096 2011-02-11 22:06 depmod.d
dr–r----- 4 root root 4096 2011-08-16 19:51 dhcp3
dr–r----- 2 root root 4096 2011-02-11 22:25 dictionaries-common
dr–r----- 3 root root 4096 2011-06-19 10:13 dkms
dr–r----- 3 root root 4096 2011-02-11 22:14 doc-base
dr–r----- 4 root root 4096 2011-04-17 18:37 dpkg
dr–r----- 3 root root 4096 2011-02-11 22:13 emacs
-r–r----- 1 root root 79 2011-02-11 22:06 environment
dr–r----- 2 root root 4096 2011-02-11 22:19 esound
dr–r----- 4 root root 4096 2011-02-11 22:15 firefox
dr–r----- 3 root root 4096 2011-02-11 22:13 firefox-3.0
dr–r----- 4 root root 4096 2011-02-11 22:12 fonts
dr–r----- 3 root root 4096 2011-02-11 22:19 foomatic
-r–r----- 1 root root 681 2011-04-18 02:51 fstab
-r–r----- 1 root root 132 2011-03-26 04:16 ftpusers
-r–r----- 1 root fuse 216 2010-12-10 23:04 fuse.conf
-r–r----- 1 root root 2987 2010-04-22 23:04 gai.conf
dr–r----- 2 root root 4096 2011-02-11 22:23 gamin
dr–r----- 6 root root 4096 2011-02-11 22:10 gconf
dr–r----- 2 root root 4096 2011-02-11 22:21 gdb
dr–r----- 6 root root 4096 2011-05-05 11:44 gdm
dr–r----- 3 root root 4096 2011-02-11 22:19 gnome
dr–r----- 2 root root 4096 2011-02-11 22:20 gnome-app-install
dr–r----- 2 root root 4096 2011-02-11 22:22 gnome-system-tools
dr–r----- 3 root root 4096 2011-02-11 22:10 gnome-vfs-2.0
-r–r----- 1 root root 10852 2007-04-28 11:27 gnome-vfs-mime-magic
dr–r----- 2 root root 4096 2011-08-20 10:59 gre.d
dr–r----- 2 root root 4096 2011-02-11 22:20 groff
-r–r----- 1 root root 1079 2011-08-23 18:04 group
-r–r----- 1 root root 1069 2011-08-23 18:04 group-
dr–r----- 2 root root 4096 2011-06-19 10:13 grub.d
-r–r----- 1 root shadow 924 2011-08-23 18:04 gshadow
-r–r----- 1 root root 914 2011-08-23 18:04 gshadow-
dr–r----- 2 root root 4096 2011-02-11 22:12 gtk-2.0
dr–r----- 3 root root 4096 2011-02-11 22:16 hal
-r–r----- 1 root root 4794 2010-04-23 04:14 hdparm.conf
-r–r----- 1 root root 92 2010-04-23 18:45 host.conf
-r–r----- 1 root root 14 2011-04-18 03:02 hostname
-r–r----- 1 root root 259 2011-04-18 03:02 hosts
-r–r----- 1 root root 580 2011-02-11 22:19 hosts.allow
-r–r----- 1 root root 880 2011-02-11 22:19 hosts.deny
dr–r----- 2 root root 4096 2011-02-11 22:22 hp
dr–r----- 3 root root 4096 2011-02-11 22:17 ifplugd
dr–r----- 2 root root 4096 2011-08-07 19:02 init
dr–r----- 2 root root 4096 2011-08-23 18:16 init.d
dr–r----- 5 root root 4096 2011-02-11 22:06 initramfs-tools
-r–r----- 1 root root 1721 2010-01-18 17:15 inputrc
dr–r----- 3 root root 4096 2009-11-05 17:56 insserv
-r–r----- 1 root root 885 2009-11-05 17:56 insserv.conf
dr–r----- 2 root root 4096 2009-11-05 17:56 insserv.conf.d
dr–r----- 2 root root 4096 2011-02-11 22:07 iproute2
-r–r----- 1 root root 26 2011-07-15 22:48 issue
-r–r----- 1 root root 19 2011-07-15 22:48 issue.net
dr–r----- 3 root root 4096 2011-08-13 13:04 java
dr–r----- 4 root root 4096 2011-08-13 17:49 java-6-sun
dr–r----- 2 root root 4096 2011-04-20 18:41 javascript-common
dr–r----- 2 root root 4096 2011-02-11 22:08 kbd
dr–r----- 5 root root 4096 2011-04-17 20:19 kernel
-r–r----- 1 root root 167 2011-04-18 03:03 kernel-img.conf
-r–r----- 1 root root 1309 2010-04-19 18:06 kerneloops.conf
-r–r----- 1 root root 61004 2011-08-20 10:59 ld.so.cache
-r–r----- 1 root root 34 2011-02-11 22:04 ld.so.conf
dr–r----- 2 root root 4096 2011-04-17 20:19 ld.so.conf.d
dr–r----- 2 root root 4096 2011-06-19 10:12 ldap
-r–r----- 1 root root 267 2010-04-23 18:45 legal
-r–r----- 1 root root 3587 2010-09-03 05:45 lftp.conf
dr–r----- 2 root root 4096 2010-03-07 00:45 libpaper.d
-r–r----- 1 root root 2570 2010-03-04 21:28 locale.alias
-r–r----- 1 root root 380 2011-04-29 10:04 localtime
dr–r----- 5 root root 4096 2011-04-17 19:09 logcheck
-r–r----- 1 root root 10788 2010-01-27 02:09 login.defs
-r–r----- 1 root root 599 2010-03-07 12:00 logrotate.conf
dr–r----- 2 root root 4096 2011-08-23 17:14 logrotate.d
dr–r----- 2 root root 4096 2010-02-23 19:51 lsb-base
-r–r----- 1 root root 3239 2009-12-04 20:46 lsb-base-logging.sh
-r–r----- 1 root root 104 2011-07-15 22:34 lsb-release
-r–r----- 1 root root 15752 2009-07-26 00:13 ltrace.conf
-r–r----- 1 root root 111 2010-04-01 16:28 magic
-r–r----- 1 root root 111 2010-04-01 16:28 magic.mime
-r–r----- 1 root root 23702 2011-08-13 17:49 mailcap
-r–r----- 1 root root 449 2010-01-16 09:05 mailcap.order
-r–r----- 1 root root 5173 2010-10-05 22:29 manpath.config
dr–r----- 2 root root 4096 2011-08-23 17:45 menu
dr–r----- 2 root root 4096 2011-08-23 17:46 menu-methods
-r–r----- 1 root root 22275 2010-01-16 09:05 mime.types
-r–r----- 1 root root 801 2010-04-19 13:30 mke2fs.conf
dr–r----- 2 root root 4096 2011-04-17 20:19 modprobe.d
-r–r----- 1 root root 198 2011-04-17 20:15 modules
dr–r----- 4 root root 4096 2011-02-11 22:23 mono
lrwxrwxrwx 1 root root 13 2011-04-18 02:51 motd -> /var/run/motd
-r–r----- 1 root root 529 2011-08-24 16:58 mtab
-r–r----- 1 root jwong 0 2011-04-17 20:20 mtab.fuselock
-r–r----- 1 root root 624 2009-11-14 03:45 mtools.conf
dr–r----- 3 root root 4096 2011-08-22 17:23 mysql
-r–r----- 1 root root 8453 2010-02-02 11:30 nanorc
dr–r----- 2 root root 4096 2009-05-01 00:07 ndiswrapper
-r–r----- 1 root root 2064 2006-11-24 04:33 netscsid.conf
dr–r----- 6 root root 4096 2011-04-19 17:27 network
-r–r----- 1 root root 91 2010-04-23 18:45 networks
-r–r----- 1 root root 513 2011-02-11 22:21 nsswitch.conf
dr–r----- 2 root root 4096 2011-02-11 22:21 obex-data-server
-r–r----- 1 root root 0 2009-12-05 09:45 odbc.ini
dr–r----- 2 root root 4096 2011-05-03 15:55 openal
dr–r----- 2 root root 4096 2011-02-11 22:13 openoffice
dr–r----- 2 root root 4096 2011-02-11 22:04 opt
-r–r----- 1 root root 870 2011-08-15 17:18 pam.conf
dr–r----- 2 root root 4096 2011-08-15 17:18 pam.d
dr–r----- 2 root root 4096 2011-02-11 22:12 pango
-r–r----- 1 root root 3 2011-04-18 03:03 papersize
-r–r----- 1 root root 1845 2011-04-30 14:09 passwd
-r–r----- 1 root root 1827 2011-04-30 14:09 passwd-
dr–r----- 2 root root 4096 2011-02-11 22:22 pcmcia
dr–r----- 5 root root 4096 2011-02-11 22:20 perl
dr–r----- 4 root root 4096 2011-04-17 19:27 php5
dr–r----- 2 root root 4096 2011-04-20 18:41 phpmyadmin
dr–r----- 5 root root 4096 2011-02-11 22:13 pm
-r–r----- 1 root root 7649 2011-02-11 22:22 pnm2ppa.conf
dr–r----- 5 root root 4096 2011-02-11 22:10 polkit-1
-r–r----- 1 root root 350 2011-04-18 03:03 popularity-contest.conf
dr–r----- 8 root dip 4096 2011-02-11 22:22 ppp
-r–r----- 1 root root 497 2011-07-20 16:45 profile
dr–r----- 2 root root 4096 2011-02-11 22:21 profile.d
-r–r----- 1 root root 2626 2009-12-04 01:11 protocols
dr–r----- 2 root root 4096 2011-02-11 22:21 pulse
dr–r----- 2 root root 4096 2011-02-11 22:08 python
dr–r----- 2 root root 4096 2011-02-11 22:06 python2.6
-r–r----- 1 root root 533 2011-08-23 21:26 rc.local
dr–r----- 2 root root 4096 2011-08-23 18:16 rc0.d
dr–r----- 2 root root 4096 2011-08-23 18:16 rc1.d
dr–r----- 2 root root 4096 2011-08-23 18:16 rc2.d
dr–r----- 2 root root 4096 2011-08-23 18:16 rc3.d
dr–r----- 2 root root 4096 2011-08-23 18:16 rc4.d
dr–r----- 2 root root 4096 2011-08-23 18:16 rc5.d
dr–r----- 2 root root 4096 2011-08-23 18:16 rc6.d
dr–r----- 2 root root 4096 2011-06-19 10:13 rcS.d
-r–r----- 1 root root 78 2011-04-19 17:39 resolv.conf
dr–r----- 3 root root 4096 2011-02-11 22:13 resolvconf
-r–r----- 1 root root 268 2009-11-10 07:50 rmt
-r–r----- 1 root root 887 2009-12-04 01:11 rpc
-r–r----- 1 root root 1217 2010-02-25 03:26 rsyslog.conf
dr–r----- 2 root root 4096 2011-02-11 22:20 rsyslog.d
dr–r----- 2 root root 4096 2011-08-07 19:02 samba
dr–r----- 3 root root 4096 2011-02-11 22:22 sane.d
-r–r----- 1 root root 3663 2010-08-18 00:55 screenrc
-r–r----- 1 root root 1107 2010-01-27 02:09 securetty
dr–r----- 4 root root 4096 2011-06-06 11:25 security
dr–r----- 2 root root 4096 2011-02-11 22:19 sensors.d
-r–r----- 1 root root 8596 2010-02-16 02:17 sensors3.conf
-r–r----- 1 root root 18832 2009-12-04 01:11 services
dr–r----- 3 root root 4096 2011-04-17 20:15 sgml
-r–r----- 1 root shadow 1220 2011-04-30 14:09 shadow
-r–r----- 1 root root 1092 2011-04-17 19:09 shadow-
-r–r----- 1 root root 181 2011-02-11 22:20 shells
dr–r----- 2 root root 4096 2011-02-11 22:21 skel
dr–r----- 3 root root 4096 2011-02-11 22:10 sound
dr–r----- 4 root root 4096 2011-02-11 22:21 speech-dispatcher
dr–r----- 2 root root 4096 2011-07-20 16:47 ssh
dr–r----- 4 root root 4096 2011-04-17 20:15 ssl
-r–r----- 1 root root 19 2010-02-05 02:35 su-to-rootrc
-r–r----- 1 root root 609 2011-04-18 03:02 sudoers
dr–r----- 2 root root 4096 2011-02-11 22:09 sudoers.d
-r–r----- 1 root root 2028 2009-12-17 04:34 sysctl.conf
dr–r----- 2 root root 4096 2011-02-11 22:06 sysctl.d
dr–r----- 2 root root 4096 2011-02-11 22:06 terminfo
-r–r----- 1 root root 11 2011-04-29 10:04 timezone
-r–r----- 1 root root 645 2010-03-07 14:58 ts.conf
-r–r----- 1 root root 1260 2008-05-30 15:22 ucf.conf
dr–r----- 3 root root 4096 2011-02-11 22:09 udev
dr–r----- 3 root root 4096 2011-02-11 22:20 ufw
dr–r----- 3 root root 4096 2011-02-11 22:22 update-manager
dr–r----- 2 root root 4096 2011-07-20 16:45 update-motd.d
dr–r----- 2 root root 4096 2010-04-14 05:52 update-notifier
-r–r----- 1 root root 300 2010-03-24 19:16 updatedb.conf
dr–r----- 2 root root 4096 2011-02-11 22:08 vim
dr–r----- 2 root root 4096 2011-08-23 18:21 vnc
-r–r----- 1 root root 10 2011-05-02 13:41 vsftpd.chroot_list
-r–r----- 1 root root 5342 2011-05-02 13:45 vsftpd.conf
dr–r----- 2 root root 4096 2011-04-17 20:14 w3m
-r–r----- 1 root root 4496 2010-09-02 01:11 wgetrc
-r–r----- 1 root root 1343 2007-01-10 03:39 wodim.conf
dr–r----- 2 root root 4096 2011-02-11 22:22 wpa_supplicant
dr–r----- 6 root root 4096 2011-02-11 22:22 xdg
-r–r----- 1 root root 289 2010-03-07 15:35 xinetd.conf
dr–r----- 2 root root 4096 2011-08-23 18:16 xinetd.d
dr–r----- 2 root root 4096 2011-02-11 22:20 xml
dr–r----- 2 root root 4096 2011-02-11 22:23 xul-ext
dr–r----- 2 root root 4096 2011-08-20 10:59 xulrunner-1.9.2
dr–r----- 3 root root 4096 2011-04-20 18:00 yum
-r–r----- 1 root root 645 2010-04-15 16:59 zsh_command_not_found

루트라서 sudo 필요없습니다. 걍 명령어 치세요.