Re: CVS commit: src/sys/kern

[David Holland <dholland-sourcechanges%netbsd.org@localhost>]

On Sun, Feb 27, 2011 at 07:12:16PM -0500, Christos Zoulas wrote:
 > don't depend on F_OK being 0.
 >   :
 > -       if ((SCARG(uap, flags) & ~(R_OK | W_OK | X_OK)) != 0) {
 > +       if ((SCARG(uap, flags) & ~(F_OK | R_OK | W_OK | X_OK)) != 0) {

That doesn't work; if F_OK isn't zero and the user passes 0, we end up
in the kauth assertion again.

mlelstv and I were just (more or less pointlessly) thrashing out
various ways to fix that in chat, but it ends up overcomplicated, so I
suggest reverting the above and instead adding

+       CTASSERT(F_OK == 0);
        if ((SCARG(uap, flags) & ~(R_OK | W_OK | X_OK)) != 0) {

so that if in the unlikely event that anyone ever tries to change F_OK
it will then get further attention.

-- 
David A. Holland
dholland%netbsd.org@localhost