(Ubuntu) setuid bash doesn't work

Here is the code:

(root:)

# mkdir /test
# cp /bin/bash /test/sbash
# chmod a+s /test/sbash

(user1:)

$ cd /test
$ ./sbash
$ mkdir trycreate
mkdir: cannot create directory `trycreate': Permission denied

And bash scripts with setuid bit set not work, either.

By the way, my setuid perl script works:

test.pl: (with setuid bit set, owner=root)

#!/usr/bin/perl
mkdir('/test/tryperlcreate') or die 'failed'; 

execute test.pl by user1 will create the directory owned by root.

Try exec ./sbash with -p.

sh:~# cp /bin/bash /bin/ape
sh:~# chmod +s /bin/ape
sh:~**$** /bin/ape -p
ape-3.2#

You cannot make scripts SUID. Fortunately.

You may be interested in the SUID-wrapper program here, though: http://isptools.sourceforge.net/suid-wrap.html

I should also add, please please please make sure that you really need to do this before you do it. SUID binaries can be a great big gaping hole in your system.

I could repost what's been done to death already, but this is a great read.

Basically setuid shell scripts don't work by default

http://www.faqs.org/faqs/unix-faq/faq/part4/section-7.html