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: AS53758 23.128.96.0/24 X-Spam-Status: No, score=-11.6 required=3.0 tests=AWL,BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,SPF_PASS, USER_IN_DEF_DKIM_WL shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by dcvr.yhbt.net (Postfix) with ESMTP id 142821F953 for ; Thu, 23 Dec 2021 15:58:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244611AbhLWP6S (ORCPT ); Thu, 23 Dec 2021 10:58:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231974AbhLWP6R (ORCPT ); Thu, 23 Dec 2021 10:58:17 -0500 Received: from mail-ua1-x935.google.com (mail-ua1-x935.google.com [IPv6:2607:f8b0:4864:20::935]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF6A5C061401 for ; Thu, 23 Dec 2021 07:58:17 -0800 (PST) Received: by mail-ua1-x935.google.com with SMTP id i6so10683953uae.6 for ; Thu, 23 Dec 2021 07:58:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=XAaR2TphAUjaXoalz8vShysblYyTXN9p/ztuuuL4G7A=; b=I4WB3hRRVWFE9Ew6LVfU6S9ODKeEW50veXpPIUP2/SQrKI53ZiEnwDL5lNpiWOUute pvZgJ9ewxp/aNRzQSZEWnaCLhBIk4SK9ArhL7KD9Uvx4k/TuD8n3Jy/MrkZpn8f8E1bS rxuTdAG/h5IHv8PK3O4sxdaRI6AUNJ9Ae7ZqhTT57vcpNedlK/72OwUj5MrXXfXwUMtI iLu59gBQ9QeDshs8Y3z9RUALmJ3i8rE+IfifA+AoLqifICexDjVv0pA+gk9CbmxI+DOq Rl8wd3leCu/mFQtQG4yBQpCeM/heWVMnGbIbti7aNOOVoBWdpa+a3qnC8RHthYI9wsCi 5PQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=XAaR2TphAUjaXoalz8vShysblYyTXN9p/ztuuuL4G7A=; b=BB/ed4JbjzAaEf5W7kex0tscdwlIWqCQpDNDZk7C3yniNoRhZRS5UM1CGcY4CqZjec D+WCd7vJ1LVRsFJOpciyNi9N3JzQ2yGJIU+lEsd8V0hkV3ap96+gPFeU58W8nvQ3V5gt L4o+fMwmFzR6uwKbaLxfXy6J56JpQhpBDLQXpBydyntZbnRFGR2arQuvpM4iDBv8z/nU T92biq0UcXzIQnRtn01FtNTHLZdWbVggFB1kX/RaW9M6yBgYMx29xw05nL0T6dVtxF4V 3nkGYLZRkP+VSoa5PGItQnqjs4TT++xgyYERxiz8GYv/x2bszZFtK6VPjezzjKhtpCBc JMlQ== X-Gm-Message-State: AOAM532zpyJcSFr/AQ+tsuH0gsJDUPHmeZUlFt26pzxuJTURucL+sIUf ReVdR7feJaroEE8kuLq4fbG1Fx9ZM8hPI3F1lmUOAA== X-Google-Smtp-Source: ABdhPJzRCDdxyF1o2JpQ1U0BA8YOLosNgo/LCD6DgXmi2wlywrOP/35bHUcFv/HWP1TbDvbW5/0Exa4IvDX/19Vnm/I= X-Received: by 2002:a67:e15a:: with SMTP id o26mr959706vsl.83.1640275096729; Thu, 23 Dec 2021 07:58:16 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Han-Wen Nienhuys Date: Thu, 23 Dec 2021 16:58:04 +0100 Message-ID: Subject: Re: [PATCH v5 16/16] reftable: be more paranoid about 0-length memcpy calls To: Junio C Hamano Cc: Han-Wen Nienhuys via GitGitGadget , git@vger.kernel.org, Jeff King , =?UTF-8?B?w4Z2YXIgQXJuZmrDtnLDsCBCamFybWFzb24=?= , Han-Wen Nienhuys Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Wed, Dec 22, 2021 at 11:50 PM Junio C Hamano wrote: > > - memcpy(r->hash_prefix, key.buf, key.len); > > + if (key.len) > > + memcpy(r->hash_prefix, key.buf, key.len); > > r->hash_prefix_len =3D key.len; > > > > if (val_type =3D=3D 0) { > > I am not sure why any of these are needed. I'm not sure they are needed, but IMO it's not worth spending brain cycles on deciding either way. Checking the length is always a safe alternative. I would support having a safe_memcpy() that does this check centrally (note how our array_copy() array function also does this check, even if it's not always needed.) --=20 Han-Wen Nienhuys - Google Munich I work 80%. Don't expect answers from me on Fridays. -- Google Germany GmbH, Erika-Mann-Strasse 33, 80636 Munich Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg Gesch=C3=A4ftsf=C3=BChrer: Paul Manicle, Halimah DeLaine Prado