Re: root permissions
Peter Wemm (peter@haywire.DIALix.COM)
Fri, 26 Aug 1994 21:17:19 +0800 (WST)
KevinTX writes:
>
> > Well, this is not a bug but a question on
> > the design of most Unix systems. It seams to me, and
> > I tried this on Ultrix 4.3, HPUX 9.01, Linux 1.1.x,
> > when root opens a file, being the owner or not, the
> > system does not check the file permissions before
> > granting him access. The same goes for writting and
> > unlinking a file.
>
> I've long considered this to be "wrong" as well. Forcing root to have to
> obey whether something is allowed to be writable by root would close up a
> lot of the various holes out there. Of course this creates problems with
> things like the traditional "passwd" program that would then have to know
> to do a chmod to give root write perms to the password file..
What about adding an option to the open() system call? eg:
open("/etc/passwd", O_WRONLY | O_ROOTPRIVS, 0);
That would allow a privileged file open to be explicit request rather
than an "accident". Still, I wonder if it'd buy anything? Would
slack programmers use the flag on everything?
At least, it'd solve the chmod inconvenience.
-Peter