Re: Can't get the set-user-id bit to work

[Paul Jarc]

Sebastian Tennant <sebyte@smolny.plus.com> wrote:
> I have a 3-line script; foo:

The setuid bit works only for binaries, not scripts.  This is a
limitation of the kernel, necessary for security.

> A cron.daily script handles mandb.  I elected to install it with the
> set-user-id bit set, as you can see:

Is it meant to be installed that way?  If not, you probably shouldn't
do that.  It might break something, or introduce a security risk.

> it certianly shouldn't have any trouble creating it in /tmp:
>
>   drwxrwxr-x  13 root root 4096 Dec 27 16:50 /tmp

With those permissions, only the root user and root group can create
files in /tmp.  To allow all users to create files there, make it
world-writable and sticky:
# chmod 1777 /tmp
# ls -ld /tmp
drwxrwxrwt  13 root root 4096 Dec 27 16:50 /tmp


paul