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[198.0.35.241]) by smtp.gmail.com with ESMTPSA id x20-20020a170902ea9400b001b9de67285dsm2190933plb.156.2023.08.10.13.18.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Aug 2023 13:18:49 -0700 (PDT) Date: Thu, 10 Aug 2023 13:18:48 -0700 From: Kees Cook To: "GONG, Ruiqi" Cc: Pablo Neira Ayuso , Jozsef Kadlecsik , Florian Westphal , Roopa Prabhu , Nikolay Aleksandrov , "Gustavo A . R . Silva" , 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 Subject: Re: [PATCH] netfilter: ebtables: replace zero-length array members Message-ID: <202308101317.7AAED4DF6A@keescook> References: <20230809075136.1323302-1-gongruiqi@huaweicloud.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230809075136.1323302-1-gongruiqi@huaweicloud.com> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 09, 2023 at 03:51:36PM +0800, GONG, Ruiqi wrote: > From: "GONG, Ruiqi" > > As suggested by Kees[1], replace the old-style 0-element array members > of multiple structs in ebtables.h with modern C99 flexible array. > > [1]: https://lore.kernel.org/all/5E8E0F9C-EE3F-4B0D-B827-DC47397E2A4A@kernel.org/ > > Link: https://github.com/KSPP/linux/issues/21 > Signed-off-by: GONG, Ruiqi In theory, this should be fine. It is possible there are userspace tools that are doing (already) buggy things that will now turn into build failures. If the userspace ebtable tools still build happily with these UAPI changes, I imagine that would be a sufficient test. Reviewed-by: Kees Cook -- Kees Cook