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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9B901C001B0 for ; Wed, 9 Aug 2023 07:00:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231337AbjHIHAN (ORCPT ); Wed, 9 Aug 2023 03:00:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37414 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230028AbjHIHAK (ORCPT ); Wed, 9 Aug 2023 03:00:10 -0400 Received: from dggsgout11.his.huawei.com (dggsgout11.his.huawei.com [45.249.212.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 25FD91BCF; Wed, 9 Aug 2023 00:00:09 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout11.his.huawei.com (SkyGuard) with ESMTP id 4RLLXf3n62z4f3jYq; Wed, 9 Aug 2023 15:00:02 +0800 (CST) Received: from [10.67.110.48] (unknown [10.67.110.48]) by APP4 (Coremail) with SMTP id gCh0CgBHI6ZxOdNkG+kkAQ--.22186S2; Wed, 09 Aug 2023 15:00:02 +0800 (CST) Message-ID: Date: Wed, 9 Aug 2023 15:00:01 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:102.0) Gecko/20100101 Thunderbird/102.11.0 Subject: Re: [PATCH v2] netfilter: ebtables: fix fortify warnings Content-Language: en-US To: Kees Cook , "Gustavo A. R. Silva" Cc: Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal , Roopa Prabhu , Nikolay Aleksandrov , Kees Cook , netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org, Wang Weiyang , Xiu Jianfeng , gongruiqi1@huawei.com References: <20230808133038.771316-1-gongruiqi@huaweicloud.com> <5E8E0F9C-EE3F-4B0D-B827-DC47397E2A4A@kernel.org> From: "GONG, Ruiqi" In-Reply-To: <5E8E0F9C-EE3F-4B0D-B827-DC47397E2A4A@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CM-TRANSID: gCh0CgBHI6ZxOdNkG+kkAQ--.22186S2 X-Coremail-Antispam: 1UD129KBjvJXoW7uF4xCw18tw1fArW5ury7Awb_yoW8KrWUpF 1vya4akr4UJ3WYqw1xXwnYyr4F93sFgF13JrW3G34rGryvqF17Ga9YkryY9a4kJwn5uF4x AF4YgrWSgFWDJFJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvIb4IE77IF4wAFF20E14v26r4j6ryUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Ar0_tr1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x 0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcVAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7Mxk0xIA0c2IE e2xFo4CEbIxvr21l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxV Aqx4xG67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a 6rW5MIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6x kF7I0E14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWrZr1j6s0DMIIF0xvEx4A2jsIE 14v26r1j6r4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr0_Gr1UYxBIdaVFxhVjvjDU0xZFpf 9x07UWE__UUUUU= X-CM-SenderInfo: pjrqw2pxltxq5kxd4v5lfo033gof0z/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/08/09 6:53, Kees Cook wrote: > > [...] >>> >>> diff --git a/include/uapi/linux/netfilter_bridge/ebtables.h b/include/uapi/linux/netfilter_bridge/ebtables.h >>> index a494cf43a755..b0caad82b693 100644 >>> --- a/include/uapi/linux/netfilter_bridge/ebtables.h >>> +++ b/include/uapi/linux/netfilter_bridge/ebtables.h >>> @@ -182,12 +182,14 @@ struct ebt_entry { >>> unsigned char sourcemsk[ETH_ALEN]; >>> unsigned char destmac[ETH_ALEN]; >>> unsigned char destmsk[ETH_ALEN]; >>> - /* sizeof ebt_entry + matches */ >>> - unsigned int watchers_offset; >>> - /* sizeof ebt_entry + matches + watchers */ >>> - unsigned int target_offset; >>> - /* sizeof ebt_entry + matches + watchers + target */ >>> - unsigned int next_offset; >>> + __struct_group(/* no tag */, offsets, /* no attrs */, >>> + /* sizeof ebt_entry + matches */ >>> + unsigned int watchers_offset; >>> + /* sizeof ebt_entry + matches + watchers */ >>> + unsigned int target_offset; >>> + /* sizeof ebt_entry + matches + watchers + target */ >>> + unsigned int next_offset; >>> + ); >>> unsigned char elems[0] __attribute__ ((aligned (__alignof__(struct ebt_replace)))); > > While we're here, can we drop this [0] in favor of []? > > -Kees > Look like it could be done. Will do in v3. Thanks! >>> }; >>> >>> diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c >>> index 757ec46fc45a..5ec66b1ebb64 100644 >>> --- a/net/bridge/netfilter/ebtables.c >>> +++ b/net/bridge/netfilter/ebtables.c >>> @@ -2115,8 +2115,7 @@ static int size_entry_mwt(const struct ebt_entry *entry, const unsigned char *ba >>> return ret; >>> >>> offsets[0] = sizeof(struct ebt_entry); /* matches come first */ >>> - memcpy(&offsets[1], &entry->watchers_offset, >>> - sizeof(offsets) - sizeof(offsets[0])); >>> + memcpy(&offsets[1], &entry->offsets, sizeof(offsets) - sizeof(offsets[0])); >> ^^^^^^^^^^^^ >> You now can replace this ____________________________________| >> with just `sizeof(entry->offsets)` >> >> With that change you can add my >> Reviewed-by: Gustavo A. R. Silva >> >> Thank you >> -- >> Gustavo >> >>> >>> if (state->buf_kern_start) { >>> buf_start = state->buf_kern_start + state->buf_kern_offset; >>> -- >>> 2.41.0 >>> > >