[musl] Re: Tweaking the program name for <err.h> functions

[Skyler Ferrante (RIT Student)]

Hi Florian,

> it's not running SUID (in AT_SECURE mode)

I see. I didn't realize that it had different behavior for setuid/not
setuid. That makes sense though, sorry for the confusion.

Skyler


On Mon, Mar 11, 2024 at 2:23 PM Florian Weimer <fweimer at redhat.com> wrote:
>
> * Skyler Ferrante:
>
> > Hmm, maybe I'm missing something, but it seems you can close(fd) for
> > the standard fds and then call execve, and the new process image will
> > have no fd 0,1,2. I've tried this on a default Ubuntu 22.04 system.
> > This seems to affect shadow-utils and other setuid/setgid binaries.
> >
> > Here is a repo I built for testing,
> > https://github.com/skyler-ferrante/fd_omission/. What is the correct
> > glibc behavior? Am I misunderstanding something?
>
> If you run it under strace, it's not running SUID (in AT_SECURE mode).
> I'm not saying we don't have bugs (although we do have some end-to-end
> AT_SECURE tests in the testsuite, but probably not for this legacy
> behavior), just that this approach to testing is questionable.
>
> Thanks,
> Florian
>