On Wed, 25 Sep 2019 17:03:06 +0200 Markus Wichmann <nullp...@gmx.net> wrote:
Dear Markus, > You might not, but a library you use might. I remember musl testing > for open FDs 0, 1, and 2 and opening /dev/null to make up for missing > FDs. And crashing (deliberately) if that fails. But then, that only > happens for elevated security contexts, i.e. setuid or "secure" mode > (which on Linux means "file capabilities set"). > > /dev/null has the distinction of being the only device POSIX actually > requires. I don't know what you might use it for. (/dev/tty is > defined, but optional.) I didn't know that, very interesting! Thanks for explaining it. Well, it just shows again how lackluster chroot() is and that the idea of pledge()/unveil() is superior. A standard library could easily unveil() the necessary files before program execution, not interfere with program operation and POSIX would also be happy. With best regards Laslo
