/etc/profile permission denied

I'm running an Ubuntu 12.04 LTS partition and I've recently have had issues logging in.

From the GUI login screen, when I enter my username and password, it takes me right back to the login screen. This is different from when I enter my username and password incorrectly.

So I entered alt+ctrl+F1 to access the terminal and I signed in. It then reads:

-bash: /etc/profile Permission denied

From what I've tested, the only commands that I can run from terminal are basic terminal commands like ls and pwd. I tried changing my access to /etc:

sudo chmod 755 /etc

I get the errors:

sudo: unable to open /etc/sudoers: Permission denied

sudo: no valid sudoers sources found, quitting

sudo: unable to initialize policy plugin

If I run it without sudo I get a permission denied. If someone knows how to get around this issue that would be great

Solution 1:

Setting permission to /etc:

Since the permission of your /etc directory is drw-rw----, you will not be able to drop down to root privilege to set the right permissions. So you'll have to get a Live Ubuntu media with which you can boot and correct the problems.

1. Boot to a live session, open a terminal and mount the target root partition:

   sudo -i
   mount /dev/sdXY /mnt
   

   (replace sdXY with that of target device, the device for /; assuming you don't have a separate partition for /etc.)

2. Make permission changes:

   chmod 755 /mnt/etc
   

   (assuming the permissions for the contents in /etc is okay.)

   reboot
   

P.S. I tried to replicate this by running sudo chmod 644 /etc and was able to recover with the steps stated above. However, I encountered additional issues with Unity plugins. The following AU Q&A helped to solve some:

• Unity doesn't load, no Launcher, no Dash appears!