From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <netfilter-devel-owner@vger.kernel.org>
X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on
	aws-us-west-2-korg-lkml-1.web.codeaurora.org
Received: from vger.kernel.org (vger.kernel.org [23.128.96.18])
	by smtp.lore.kernel.org (Postfix) with ESMTP id 67E22C41513
	for <netfilter-devel@archiver.kernel.org>; Wed,  9 Aug 2023 20:21:02 +0000 (UTC)
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
        id S231177AbjHIUVB (ORCPT
        <rfc822;netfilter-devel@archiver.kernel.org>);
        Wed, 9 Aug 2023 16:21:01 -0400
Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41258 "EHLO
        lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
        with ESMTP id S229543AbjHIUVA (ORCPT
        <rfc822;netfilter-devel@vger.kernel.org>);
        Wed, 9 Aug 2023 16:21:00 -0400
Received: from Chamillionaire.breakpoint.cc (Chamillionaire.breakpoint.cc [IPv6:2a0a:51c0:0:237:300::1])
        by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9714110E9;
        Wed,  9 Aug 2023 13:21:00 -0700 (PDT)
Received: from fw by Chamillionaire.breakpoint.cc with local (Exim 4.92)
        (envelope-from <fw@strlen.de>)
        id 1qTpfq-0001c2-Gy; Wed, 09 Aug 2023 22:20:54 +0200
Date:   Wed, 9 Aug 2023 22:20:54 +0200
From:   Florian Westphal <fw@strlen.de>
To:     Justin Stitt <justinstitt@google.com>
Cc:     Pablo Neira Ayuso <pablo@netfilter.org>,
        Jozsef Kadlecsik <kadlec@netfilter.org>,
        Florian Westphal <fw@strlen.de>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        linux-hardening@vger.kernel.org, Kees Cook <keescook@chromium.org>,
        netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 7/7] netfilter: xtables: refactor deprecated strncpy
Message-ID: <20230809202054.GC3325@breakpoint.cc>
References: <20230809-net-netfilter-v2-0-5847d707ec0a@google.com>
 <20230809-net-netfilter-v2-7-5847d707ec0a@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230809-net-netfilter-v2-7-5847d707ec0a@google.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk
List-ID: <netfilter-devel.vger.kernel.org>
X-Mailing-List: netfilter-devel@vger.kernel.org

Justin Stitt <justinstitt@google.com> wrote:
> Prefer `strscpy_pad` as it's a more robust interface whilst maintaing
> zero-padding behavior.
> 
> There may have existed a bug here due to both `tbl->repl.name` and
> `info->name` having a size of 32 as defined below:
> |  #define XT_TABLE_MAXNAMELEN 32
> 
> This may lead to buffer overreads in some situations -- `strscpy` solves
> this by guaranteeing NUL-termination of the dest buffer.

I don't think we need to use _pad here.