Log in + permission problem

[Goran]

Hi ! On a computer in school I can login only as root. When I added a new user and set a password and tried to login with that username i got the message "/bin/sh permission denied" and I get returned to the login prompt. I can't understand what the problem is because when I ran ls -al as root I got:

drwxr-xr-x 20 root root 4096 Jul 6 20:18 ./
drwxr-xr-x 20 root root 4096 Jul 6 20:18 ../

for /
-----------------------------------------------------------------------------------------------------------;
drwxrwxrwx 2 root bin 4096 Jun 16 11:31 bin/

for /bin and:
-----------------------------------------------------------------------------------------------------------;
lrwxrwxrwx 1 root root 4 Feb 2 18:41 sh -> bash*
-rwxrwxrwx 1 root bin 628640 May 22 20:01 bash*

for /bin/bash and /bin/sh
-----------------------------------------------------------------------------------------------------------;
for sh and bash. On the other files it is obvious that someone changed file permissions but I still don't get it why I can't login as another user...

[monkey8]

All users have *write* access to /bin/bash ? That can't be right...

[Goran]

As I said it is a school computer for learnig purposes A lot of people typed and tested a lot of commands there .....

[Goran]

userx:1000:100::/home/userx:/bin/bash -- this is from /etc/passwd, any thoughts ?