Re: [PATCH 3/3] revision: avoid leak when preparing bloom filter for "/"

[Taylor Blau <me@ttaylorr.com>]

On Tue, Aug 04, 2020 at 09:09:21AM -0400, Derrick Stolee wrote:
> On 8/4/2020 3:50 AM, Jeff King wrote:
> > If we're given an empty pathspec, we refuse to set up bloom filters, as
> > described in f3c2a36810 (revision: empty pathspecs should not use Bloom
> > filters, 2020-07-01).
> >
> > But before the empty string check, we drop any trailing slash by
> > allocating a new string without it. So a pathspec consisting only of "/"
> > will allocate that string, but then still cause us to bail, leaking the
> > new string. Let's make sure to free it.
> >
> > Signed-off-by: Jeff King <peff@peff.net>
> > ---
> > Just noticed while reading the function to fix the previous patch.
> >
> > I'm not even sure if it's possible to get here with a pathspec of "/",
> > since we'd probably give a "/ is outside repository" error before then.
> >
> > So maybe this case doesn't even matter. If it doesn't, then it might
> > simplify the function a bit to do the empty-pathspec check before

For what it's worth, I am almost certain that this isn't possible after
your last patch, but I also agree that it's not hurting anything in the
meantime, either. So...

> > handling trailing slashes. But handling it does help make it more clear
> > this function is doing the right thing no matter what input it is given,
> > so that's what I went with here.
>
> Works for me. Thanks for your careful attention here.

Works for me, too.

  Reviewed-by: Taylor Blau <me@ttaylorr.com>

> -Stolee
>
> >  revision.c | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/revision.c b/revision.c
> > index 5ed86e4524..b80868556b 100644
> > --- a/revision.c
> > +++ b/revision.c
> > @@ -702,6 +702,7 @@ static void prepare_to_use_bloom_filter(struct rev_info *revs)
> >  	len = strlen(path);
> >  	if (!len) {
> >  		revs->bloom_filter_settings = NULL;
> > +		free(path_alloc);
> >  		return;
> >  	}
> >
> >

Thanks,
Taylor