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

On Wednesday, July 25, 2018 9:02:50 AM EDT Ondrej Mosnacek wrote: > On Wed, Jul 25, 2018 at 2:48 PM Steve Grubb <sgrubb(a)redhat.com&gt; wrote: > > On Wednesday, July 25, 2018 3:44:07 AM EDT Ondrej Mosnacek wrote: > > > On Wed, Jul 25, 2018 at 3:11 AM Steve Grubb <sgrubb(a)redhat.com&gt; 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(a)redhat.com&gt; > > > > > > > > > > > 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... > > > > What is asked for is the full path that dirfd was opened with. I can take > > care of everything else. > > But where/how should that path be logged? In case of renameat(), for > example, we have 6 (!) path components: > <src_dir>/<src_parent>/<src_child> and <dst_dir>/<dst_parent>/<dst_child> > > (I am assuming the child paths always represent just the last path > component based on the observed inodes of the parent/child records.) > > Current record format can distinguish between PARENT and child > (DELETE/CREATE), but there is no nametype for the dirfd path. That's > why I am leaning towards just logging the full "<*_dir>/<*_parent>" > path in the PARENT record. Or do you prefer that we add a new nametype > for the dirfd path? You could make a new nametype so that we can make sense of it. But do you have all of the required information for a PATH record? I thought that you were making a new record type since you have abbreviated information.