On Mon, 15 Mar 2021 15:18:48 +0000 "Dr. David Alan Gilbert" <dgilb...@redhat.com> wrote:
> * Greg Kurz (gr...@kaod.org) wrote: > > On Sun, 14 Mar 2021 19:36:04 -0400 > > Vivek Goyal <vgo...@redhat.com> wrote: > > > > > On Fri, Mar 12, 2021 at 03:10:03PM +0100, Greg Kurz wrote: > > > > POSIX.1-2017 clearly stipulates that empty filenames aren't > > > > allowed ([1] and [2]). Since virtiofsd is supposed to mirror > > > > the host file system hierarchy and the host can be assumed to > > > > be linux, we don't really expect clients to pass requests with > > > > an empty path in it. If they do so anyway, this would eventually > > > > cause an error when trying to create/lookup the actual inode > > > > on the underlying POSIX filesystem. But this could still confuse > > > > some code that wouldn't be ready to cope with this. > > > > > > > > Filter out empty names coming from the client at the top level, > > > > so that the rest doesn't have to care about it. This is done > > > > everywhere we already call is_safe_path_component(), but > > > > in a separate helper since the usual error for empty path > > > > names is ENOENT instead of EINVAL. > > > > > > > > [1] > > > > https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap03.html#tag_03_170 > > > > [2] > > > > https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13 > > > > > > > > Signed-off-by: Greg Kurz <gr...@kaod.org> > > > > > > Hi Greg, > > > > > > Minor nit, if you happen to respin this patch, it probably should come > > > before the first patch in series. Once we make it clear that file server > > > is not expecting empty path in these top level functions, then it is > > > easy to clear AT_EMPTY_PATH in function these paths are calling as > > > appropriate. > > > > > > > The patch order is chronological : I just spotted the AT_EMPTY_PATH > > oddity before coming up with the bigger hammer of patch 3. But you're > > right, it probably makes more sense to do the other way around. > > > > > What about lo_create(). Should we put a check in there as well. > > > > > > > Good catch ! I'll post a v2 then ;) > > I'm just brewing a pull now, since soft freeze is tomorrow. > I'll take 3,1,2 - please follow up with a separate lo_create one - we > can add that later. > Sure, I'll do that. Cheers, -- Greg
