SUID not working with shell script
I have created a small shell script with the following content:
cat /usr/bin/checksuid.sh
!/bin/bash
echo "Hello" > /etc/myfile.cnf
ls -l /usr/bin/checksuid.sh
-rwsr-xr-x 1 root root 56 Sep 9 12:56 /usr/bin/checksuid.sh
I have also created a file /etc/myfile.cnf with root account and set permissions as below:
-rw-r--r-- 1 root root 6 Sep 9 12:26 /etc/myfile.cnf
When I execute /usr/bin/checksuid.sh from a non-root account, I get the following error:
/usr/bin/checksuid.sh: line 3: /etc/myfile.cnf: Permission denied
Can some one help you that why SUID is not working?
Answer
Shell scripts can't be SUID. See http://www.faqs.org/faqs/unix-faq/faq/part4/section-7.html