Re^3: Setuid script not working

Replies are listed 'Best First'.
Re^4: Setuid script not working by afoken (Chancellor) on Apr 30, 2010 at 07:51 UTC
Linux, like many other Unix variants, ignores the setuid-bit on scripts. So your script runs as unprivileged user. Unprivileged users aren't allowed to change the UID or GID, hence the "Operation not permitted" error. Perl once had a separate interpreter, suidperl, that was installed setuid root, and that should respect the setuid-bit on scripts. It never worked as secure as it should, so it was deprecated and finally removed. Consider using sudo, as recommended in perl587delta. Read perlsec for a different approach. A third approach may be splitting the job into a privileged daemon and an unprivileged front-end, communicating over unix domain sockets or named pipes. Alexander -- Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)	[reply]
Re^4: Setuid script not working by ikegami (Patriarch) on Apr 30, 2010 at 21:12 UTC
`strace` will give you the same message `setuid32(0) = -1 EPERM (Operation not permitted)` [download] Not that helpful, except it tells you which system call's man page you should be reading. `$ man setuid32 ... EPERM The user is not privileged (Linux: does not have the CAP_SETUID capability) and uid does not match the real UID or saved set-user-ID of the calling process. ...` [download]	[reply] [d/l] [select]
Re^4: Setuid script not working by druidmatrix (Acolyte) on Apr 30, 2010 at 07:53 UTC
Thank you for the suggestions. I believe the root cause has been exposed in the thread above; however, if it is not too much, I would be interested in a simple example of using backtrace/strace to investigate an issue like this.	[reply]
Re^5: Setuid script not working by Anonymous Monk on Apr 30, 2010 at 08:44 UTC
I would be interested in a simple example of using backtrace/strace to investigate an issue like this. Instead of `some command` as in `foo.pl` or `perl foo.pl` you prefix with strace, as in `strace perl foo.pl ...` and then you watch	[reply] [d/l] [select]
Re^4: Setuid script not working by druidmatrix (Acolyte) on Apr 30, 2010 at 08:50 UTC
Once again, thank you for your response regarding the setuid module/part that is required to run setuid programs. I believe it is still possible to configure this with the current installer, however, I am having some issues with doing so silently (please see my response in the thread above). Also, very grateful for the lil' strace tutorial above! :)	[reply]