From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 927FE1F85D for ; Wed, 11 Jul 2018 14:27:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388679AbeGKOca (ORCPT ); Wed, 11 Jul 2018 10:32:30 -0400 Received: from cloud.peff.net ([104.130.231.41]:55220 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S2387949AbeGKOca (ORCPT ); Wed, 11 Jul 2018 10:32:30 -0400 Received: (qmail 10458 invoked by uid 109); 11 Jul 2018 14:27:54 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with SMTP; Wed, 11 Jul 2018 14:27:53 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 7366 invoked by uid 111); 11 Jul 2018 14:27:55 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.94) with (ECDHE-RSA-AES256-GCM-SHA384 encrypted) SMTP; Wed, 11 Jul 2018 10:27:55 -0400 Authentication-Results: peff.net; auth=none Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Wed, 11 Jul 2018 10:27:52 -0400 Date: Wed, 11 Jul 2018 10:27:52 -0400 From: Jeff King To: Henning Schild Cc: git@vger.kernel.org, Eric Sunshine , Junio C Hamano , Martin =?utf-8?B?w4VncmVu?= , Ben Toews , Taylor Blau , "brian m . carlson" Subject: Re: [PATCH v2 6/9] gpg-interface: do not hardcode the key string len anymore Message-ID: <20180711142751.GF23835@sigill.intra.peff.net> References: <7300c85a1c6d484c781cc80b307b5e7f085ac226.1531208187.git.henning.schild@siemens.com> <20180710154931.GA23624@sigill.intra.peff.net> <20180711105459.57ed99cc@md1pvb1c.ad001.siemens.net> <20180711123425.GB23835@sigill.intra.peff.net> <20180711154619.7b574dff@md1pvb1c.ad001.siemens.net> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20180711154619.7b574dff@md1pvb1c.ad001.siemens.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Wed, Jul 11, 2018 at 03:46:19PM +0200, Henning Schild wrote: > > I think it's worth addressing in the near term, if only because this > > kind of off-by-one is quite subtle, and I don't want to forget to deal > > with it. Whether that happens as part of this patch, or as a cleanup > > before or after, I'm not picky. :) > > I get that and if anyone is willing to write that code, i will base my > patches on it. What i want to avoid is taking responsibility for > problems i did not introduce, just because i happen to work on that > code at the moment. Keeping track of that (not forgetting) is also not > for the random contributor like myself. It doesn't make sense to do a patch before your series, since it would just be: if (strlen(found) > 16) ... which would get obliterated by your patch. The patch after is shown below. But frankly, it seems a lot easier to just handle this while you are rewriting the code. -- >8 -- Subject: [PATCH] gpg-interface: handle off-by-one parsing gpg output When parsing gpg's VALIDSIG lines, we look for a space followed by the signer information. Because we use strchrnul(), though, if the space is missing we'll end up pointing to the trailing NUL. When we try to move past that space, we have to handle the NUL case separately to avoid accidentally stepping out of the string entirely. Signed-off-by: Jeff King --- gpg-interface.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/gpg-interface.c b/gpg-interface.c index bf8d567a4c..139b0f561e 100644 --- a/gpg-interface.c +++ b/gpg-interface.c @@ -97,7 +97,7 @@ static void parse_gpg_output(struct signature_check *sigc) sigc->key = xmemdupz(found, next - found); /* The ERRSIG message is not followed by signer information */ if (sigc-> result != 'E') { - found = next + 1; + found = *next ? next + 1 : next; next = strchrnul(found, '\n'); sigc->signer = xmemdupz(found, next - found); } -- 2.18.0.400.g702e398724