On Sat, Oct 05, 2013 at 03:22:36PM -0600, Todd C. Miller wrote:
> On Wed, 28 Aug 2013 22:34:26 -0400, Kenneth R Westerback wrote:
>
> > > @@ -552,11 +552,16 @@ ELFNAME2(exec,makecmds)(struct proc *p,
> > >
> > > for (i = 0, pp = ph; i < eh->e_phnum; i++, pp++) {
> > > if (pp->p_type == PT_INTERP && !interp) {
> > > - if (pp->p_filesz >= MAXPATHLEN)
> > > + if (pp->p_filesz < 2 || pp->p_filesz >= MAXPATHLEN)
> >
> > Still think you're depriving yourself of one character out by using
> > ">=" instead of ">".
>
> I'm not sure about this. We want to limit the path length to
> MAXPATHLEN-1 since we include the NUL terminator in MAXPATHLEN.
> The buffer we get from namei_pool is MAXPATHLEN long and the
> read_from() function just calls vn_rdwr(). If we allow interp to
> be MAXPATHLEN, is there any guarantee that it will end in a NUL
> byte?
>
> - todd
My reading at the time convinced me that p_filesz also includes the NUL. So
using >= left room for two NULs.
But I am not trying to hold up either version, since I don't really
understand the relevant code. :-)
.... Ken
