Re: [PATCH] fsckObjects tests: show how v2.17.1 can exploit downstream

From: Junio C Hamano <gitster@pobox.com>
Date: May 30, 2018, 01:32 UTC
Message-ID: <xmqqk1rmexng.fsf@gitster-ct.c.googlers.com>
In-Reply-To: <20180529212458.GC7964@sigill.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 8 quoted lines

>> It's worth testing for this explicitly. So let's amend the tests added
>> in 73c3f0f704 ("index-pack: check .gitmodules files with --strict",
>> 2018-05-04) to show how this can result in a v2.17.1 client passing
>> along the evil objects.
>
> I'm not sure what testing this buys us. If it stopped passing them
> along, would we consider that a regression? This seems more like a
> documentation issue than something that needs to be tested.

I tend to agree. The recommendation of the release notes is about protecting the place downstream would pull from, by telling Git to vet the pushes into that place and that is why receive.fsckObjects is mentioned there. Nobody sane would expect receive.fsckObjects to do anything when that central place fetches from elsewhere, and I am not sure what additional value it buys us(over the tests we already have) to test that diabled transfer.fsckObjects are truly disabled.

If we want to also encourage people to vet their own "fetches", I am not against extending documentation. It just is different from "we extended the mechanism to help server side protect their clients" that was the focus of (updated, relative to what is in the tarball) the description in the release notes.

Thanks.