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=-11.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 87218C4338F for ; Thu, 29 Jul 2021 18:58:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 675CD600D4 for ; Thu, 29 Jul 2021 18:58:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229721AbhG2S67 (ORCPT ); Thu, 29 Jul 2021 14:58:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:54186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229713AbhG2S66 (ORCPT ); Thu, 29 Jul 2021 14:58:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7D1F9600D4; Thu, 29 Jul 2021 18:58:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1627585135; bh=NY+6KsF6TgwvjW8V2qdlD2zqaxdlHCFW8WbLHI1uw44=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=QwbKTXNKGQlFHhv+nWwVAGS0y7dhrRo4QVZVXmOtNRN5nEqtsizCnwgYVL71jdemC NN4LRUz2GWMm7y5nxjYEDLhzAkGKRRgwxxSk0RtIMXokH62NJ6mpGF6A4PMG9LR/dk TFkkqH24xr7RZti78Lg43eSuDbQW/o4UTfuxqASt48qIZ7hGRVSrrGAHfGoGqApQr4 fe/qqMg9s0eu93lcxSA+fP7WwiK2Zm7316Nw0lTenmESdj7Qq2k4auX+VlqVjOzIyH tJgu8hsfbG/DoN1PkOib/PnMN36fOPMKqtasZoBoWlwaNtiGVNPNof0RnW7kK1gS1x /NEEryLj0coQw== Date: Thu, 29 Jul 2021 11:58:50 -0700 From: Jakub Kicinski To: Kees Cook Cc: linux-hardening@vger.kernel.org, "Gustavo A. R. Silva" , Keith Packard , Greg Kroah-Hartman , Andrew Morton , linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-staging@lists.linux.dev, linux-block@vger.kernel.org, linux-kbuild@vger.kernel.org, clang-built-linux@googlegroups.com Subject: Re: [PATCH 54/64] ipv6: Use struct_group() to zero rt6_info Message-ID: <20210729115850.7f913c73@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com> In-Reply-To: <20210727205855.411487-55-keescook@chromium.org> References: <20210727205855.411487-1-keescook@chromium.org> <20210727205855.411487-55-keescook@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 27 Jul 2021 13:58:45 -0700 Kees Cook wrote: > In preparation for FORTIFY_SOURCE performing compile-time and run-time > field bounds checking for memset(), avoid intentionally writing across > neighboring fields. > > Add struct_group() to mark region of struct rt6_info that should be > initialized to zero. memset_after() ? > diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h > index 15b7fbe6b15c..9816e7444918 100644 > --- a/include/net/ip6_fib.h > +++ b/include/net/ip6_fib.h > @@ -205,20 +205,22 @@ struct fib6_info { > > struct rt6_info { > struct dst_entry dst; > - struct fib6_info __rcu *from; > - int sernum; > - > - struct rt6key rt6i_dst; > - struct rt6key rt6i_src; > - struct in6_addr rt6i_gateway; > - struct inet6_dev *rt6i_idev; > - u32 rt6i_flags; > - > - struct list_head rt6i_uncached; > - struct uncached_list *rt6i_uncached_list; > - > - /* more non-fragment space at head required */ > - unsigned short rt6i_nfheader_len; > + struct_group(init, > + struct fib6_info __rcu *from; > + int sernum; > + > + struct rt6key rt6i_dst; > + struct rt6key rt6i_src; > + struct in6_addr rt6i_gateway; > + struct inet6_dev *rt6i_idev; > + u32 rt6i_flags; > + > + struct list_head rt6i_uncached; > + struct uncached_list *rt6i_uncached_list; > + > + /* more non-fragment space at head required */ > + unsigned short rt6i_nfheader_len; > + ); > }; > > struct fib6_result { > diff --git a/net/ipv6/route.c b/net/ipv6/route.c > index 6b8051106aba..bbcc605bab57 100644 > --- a/net/ipv6/route.c > +++ b/net/ipv6/route.c > @@ -327,9 +327,7 @@ static const struct rt6_info ip6_blk_hole_entry_template = { > > static void rt6_info_init(struct rt6_info *rt) > { > - struct dst_entry *dst = &rt->dst; > - > - memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst)); > + memset(&rt->init, 0, sizeof(rt->init)); > INIT_LIST_HEAD(&rt->rt6i_uncached); > } >