From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.0 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id 9240D1F61A for ; Sat, 29 Feb 2020 15:39:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727113AbgB2PjA (ORCPT ); Sat, 29 Feb 2020 10:39:00 -0500 Received: from mail-wm1-f65.google.com ([209.85.128.65]:38435 "EHLO mail-wm1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727070AbgB2PjA (ORCPT ); Sat, 29 Feb 2020 10:39:00 -0500 Received: by mail-wm1-f65.google.com with SMTP id u9so676571wml.3 for ; Sat, 29 Feb 2020 07:38:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=KCvuD5ELgtiWpskH3S/8W/odtOueVUa/r8DAnQJgjcY=; b=ZhE6/rMVrldMatABGozaEi8dc1Ly1V6UupsAEG72Y4pFTFtdPjaYRg/Y+M6wVUNDvJ GOZwKWxki4wgFlFQiwjqxrQsqNACByIZd9FzSSHB9D9bgWscGu40W6Il7mUyNDDKntHH Hzg1wyJuFDsp3cg/J2o028NLYY4mCzL0OOSKDVFjtl/D3rHG6wldxlwfIQFFjBNpaV9O FvVU/ysDv5nL10SrZ5MoDxSsX3jOqsOx9qdwfmtk3f1Fb9VITPBXiRLyNN9hMjQgu9S3 ZkdUcwr/bSQhwfdCYXIMJjkbd1DaHNGa7L+lAwybaPESxb4Uni06Z2ESvLcvEGeb8ZsO XWDQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=KCvuD5ELgtiWpskH3S/8W/odtOueVUa/r8DAnQJgjcY=; b=EjsIAeMvOtzygBWIitqvKenZbdQsK99HA1FB6h9tmJGWY1clKxoVEBmXE4KTFyLHEG BHmzm2ctTADbOaV8W/3bbDsyF/THDcShC0WuEfQn+9gtbu6L90p1nhpSCcFvXEeSHWcd fsDe0ayj7D0XdohkqbqIgSTg5XOJx/trWFYOXjD7mNcuCLK6io4CXXZnCyPHIzWim9mK NaEg4//AlRHN363M5Ack4TBMFKUOX0PVGnrvDAn8RC/1Cv1iqICMCYAiKjVpdCM2YitT qFmIPZhn7UFssZzu/xE9OVoGUCBxsiefmXJXK2b9lw7oubYxSC53TMqqBtcTVHt41jJx oGCw== X-Gm-Message-State: APjAAAU39Vbi4YPlUqPgLi+IhqOiO5Te0JF7gvucjL2mBGxVjnuLx3ZI 9ffeQPJPxefzolsv/dCWNWA= X-Google-Smtp-Source: APXvYqy6REjsYdW5sjgKend50Q6pDOA8cWneHi1w5d2ej/HY2v+wJ+ZNXZN+BqNdoS73tDxMscYoaw== X-Received: by 2002:a7b:cbcf:: with SMTP id n15mr10281121wmi.21.1582990739014; Sat, 29 Feb 2020 07:38:59 -0800 (PST) Received: from doriath (87-231-246-247.rev.numericable.fr. [87.231.246.247]) by smtp.gmail.com with ESMTPSA id j5sm18008717wrw.24.2020.02.29.07.38.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 29 Feb 2020 07:38:58 -0800 (PST) Date: Sat, 29 Feb 2020 16:38:55 +0100 From: Damien Robert To: Jeff King Cc: git@vger.kernel.org, Junio C Hamano , Derrick Stolee , William Baker Subject: Re: [PATCH 1/1] midx.c: fix an integer overflow Message-ID: <20200229153855.o2s2lv4qiltej4ej@doriath> X-PGP-Key: http://www.normalesup.org/~robert/pro/files/Damien_Olivier_Robert.asc X-Start-Date: Sat, 29 Feb 2020 15:31:57 +0100 References: <20200228162450.1720795-1-damien.olivier.robert+git@gmail.com> <20200228185525.GB1408759@coredump.intra.peff.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200228185525.GB1408759@coredump.intra.peff.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org >From Jeff King, Fri 28 Feb 2020 at 13:55:25 (-0500) : > Makes sense. Such a midx shouldn't be generated in the first place, but > we should handle it robustly if we do see one. This midx was actually written by `git multi-pack-index write`, when there is no pack files in the store. > for (i = 1; i < m->num_objects; i++) { > ... > nth_midxed_object_oid(&oid1, m, i - 1); > nth_midxed_object_oid(&oid2, m, i); > ... > } We could, but this mean that we have to shift all values of i by one in the body. My patch has a smaller diff :) > Though I almost wonder if we should be catching "m->num_objects == 0" > early and declaring the midx to be bogus This is probably the best solution. Should I also catch m->num_objects == 1? Having a midx with only one pack does not make much sense either. > (it's not _technically_ wrong, but I'd have to suspect a bug in anything > that generated a 0-object midx file). So mid.c:926 calls write_midx_header unconditionally. written = write_midx_header(f, num_chunks, packs.nr - dropped_packs); Maybe we could check that packs.nr - dropped_packds is > 0 first. So I can reroll. - I'll add a warning to verify if there is no pack in the midx. What about when there is one pack? - Should I update write_midx_internal to not write anything if there is no pack? What about if there is only one pack? - Should I add tests? -- Damien