From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-14.6 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94FB0C433DF for ; Fri, 14 Aug 2020 15:08:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6DBDC20774 for ; Fri, 14 Aug 2020 15:08:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="LEWYvBdN" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728212AbgHNPI0 (ORCPT ); Fri, 14 Aug 2020 11:08:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726662AbgHNPIZ (ORCPT ); Fri, 14 Aug 2020 11:08:25 -0400 Received: from mail-io1-xd43.google.com (mail-io1-xd43.google.com [IPv6:2607:f8b0:4864:20::d43]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5122CC061385 for ; Fri, 14 Aug 2020 08:08:25 -0700 (PDT) Received: by mail-io1-xd43.google.com with SMTP id u126so10970010iod.12 for ; Fri, 14 Aug 2020 08:08:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=6/s2FrX3sOZH7no5QOEmHRzOhQVsVJV+GlCWiadD/1Y=; b=LEWYvBdNwTdiV0b8gagS099psX2ZTBY08MCdDLkfhQmHSUVkjzakpT0EfxfiCAYaE8 /OkkJXoSbJ6veoGQVa3lmvWYmhsJF9jcEWcztXamvh77ReCnPiG0d1cetjiChrUMi4vf TvWqrjfc1wIT3ogVPxlvE7jo7QJHGBLIcpZF9Zoc/LQby6CVF9FdDkVFf5S99X97VslS qPlRhUMonmBDJLxsx5hj8Hu3cAaDPX5T8Gh2CsbatiS3i39mWQ3efAOzsbdT7ZWO3T/q jx1fhEqDviWXcPyOI2PZ5vjEBUV9/BV04FBlc7tKTj2Q9cBwg/KTZozPjg3a04C+IqT0 rhww== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=6/s2FrX3sOZH7no5QOEmHRzOhQVsVJV+GlCWiadD/1Y=; b=mUhXKwt/xfm5WWdbf0RUE67RR8B6jayFygFIw5oAi+Hat/hYlD0V7pqWmXr8NniYpJ TPKoJkQHlkYeCoG6Becso2XxeYakrjFtEoNp/bA8mFkzEQGO8q7RbPyg/Zv00BU23kVh joV9N0m5VFJSyUR1gy28Vg03nyKkCjcFYritqz2hGvLCEtPFZr2jUyv9kU6zEZvleX1i hHq9n1IvPYwEZ3CahRWafNu/gB32fFtiha4AbfxHOHkiZCqJ5GUNxI70zI8KBmcUp3dE eziCqlbH1PX50rW0euUJjyyFLa7WoGfpuz6YSi6uoHhS/AN34TVkecUJ0k3q5wQ90Vay MBrA== X-Gm-Message-State: AOAM530vl3CJ20rMOb/V0023YyDMwaKg/WqZNFabOH71QgvQ6vrYBRH1 k91yE6xhJspRVnQNqjQS9txZPhoTjRSEk9DEy+KWoQ== X-Google-Smtp-Source: ABdhPJzdGGuDLFD574yj/KgkS3PLqUK92XBd83rc5Qk4H3COqG6GLDYdIApTwhzmJJy7esoAuG0qE1EejRn5qkW3fKM= X-Received: by 2002:a02:3f0d:: with SMTP id d13mr3023467jaa.99.1597417702800; Fri, 14 Aug 2020 08:08:22 -0700 (PDT) MIME-Version: 1.0 References: <20200814110428.405051-1-mkl@pengutronix.de> <20200814110428.405051-2-mkl@pengutronix.de> In-Reply-To: From: Eric Dumazet Date: Fri, 14 Aug 2020 08:08:11 -0700 Message-ID: Subject: Re: [PATCH 1/6] can: j1939: fix kernel-infoleak in j1939_sk_sock2sockaddr_can() To: Alexander Potapenko Cc: Marc Kleine-Budde , Networking , David Miller , linux-can@vger.kernel.org, kernel@pengutronix.de, syzbot , Robin van der Gracht , Oleksij Rempel Content-Type: text/plain; charset="UTF-8" Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Aug 14, 2020 at 6:20 AM Alexander Potapenko wrote: > > > > On Fri, Aug 14, 2020, 13:04 Marc Kleine-Budde wrote: >> >> From: Eric Dumazet >> net/can/j1939/socket.c | 5 +++++ >> 1 file changed, 5 insertions(+) >> >> diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c >> index 78ff9b3f1d40..b634b680177f 100644 >> --- a/net/can/j1939/socket.c >> +++ b/net/can/j1939/socket.c >> @@ -553,6 +553,11 @@ static int j1939_sk_connect(struct socket *sock, struct sockaddr *uaddr, >> static void j1939_sk_sock2sockaddr_can(struct sockaddr_can *addr, >> const struct j1939_sock *jsk, int peer) >> { >> + /* There are two holes (2 bytes and 3 bytes) to clear to avoid >> + * leaking kernel information to user space. >> + */ > > > Do we want to keep these "2 bytes and 3 bytes' in sync with the struct layout in the future? Maybe it's not worth it to mention the exact sizes? struct is uapi, you will have a hard time trying to use these holes, since old kernels were sending crap/garbage/passwords ;)