Re: [RFC PATCH ghak9 0/3] audit: Record the path of FDs passed to *at(2) syscalls

Ondrej Mosnacek
2018-07-25T07:44:19Z

On Wed, Jul 25, 2018 at 3:11 AM Steve Grubb <sgrubb@redhat.com> wrote:
> On Tuesday, July 24, 2018 6:15:54 PM EDT Paul Moore wrote:
> > On Tue, Jul 24, 2018 at 10:12 AM Ondrej Mosnacek <omosnace@redhat.com>
> > > Beyond that, there is really no information in the records that would
> > > allow reconstructing which PARENT path belongs to which CREATE/DELETE
> > > path... (Intuitively you can guess that src will come before dst, but
> > > that is not very reliable.) I think a "parent inode" field in the PATH
> > > records could fix this, but maybe there is a better solution...
> >
> > I have my suspicions, but I would be curious to hear from Steve how
> > the reconstruction is typically handled.
>
> For any *at function when the dirfd is not AT_FDCWD, it goes badly. If its a
> old style syscall without the dirfd, then if the first character is '/' use
> that. Otherwise concatonate cwd and path and pass it to realpath to sort out.

In that case it seems the best fix for openat() et al. would be to
somehow always force outputting the full path when dirfd != AT_FDCWD.
Hopefully that won't require too much hacking around...

--
Ondrej Mosnacek <omosnace at redhat dot com>
Associate Software Engineer, Security Technologies
Red Hat, Inc.