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 478B0C43334 for ; Tue, 28 Jun 2022 17:55:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232568AbiF1RzD (ORCPT ); Tue, 28 Jun 2022 13:55:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232461AbiF1RzC (ORCPT ); Tue, 28 Jun 2022 13:55:02 -0400 Received: from mail-pj1-x1032.google.com (mail-pj1-x1032.google.com [IPv6:2607:f8b0:4864:20::1032]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03010EAD for ; Tue, 28 Jun 2022 10:55:00 -0700 (PDT) Received: by mail-pj1-x1032.google.com with SMTP id c6-20020a17090abf0600b001eee794a478so6039839pjs.1 for ; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=Lpc3rw2lUDFTgNuiFkNi7vJ3FOoQQ8sPNV+A/xT7kPgFFi5TelrrdXlIUbrL4j9GT+ 3+ei8DuymmFwmq4TMtVSFXVwj/BEoFuIu2AqPN9i6R5zOS+ndUs4OIvpg1Fj2tZP3rAs mZTqNdFC15vlNUFmjWu7inrraPu1BA3Mkzqts= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=mnvj8a7Pef+MCWM33t/B/a8Dmkm80XYIT94tqcmYm7lE0U+Uew/j90RDEvVSLfm4VB /1ox+OaGOUuSnasX39pTk8zzihP7TfozQzVEPTCn0f4+H5YtQwienLkwc+7CdX4p7Y2m R04UBT5rUx+O8Ezw2ti2OHobZK5yp+3uR8dr2iHSuPJq/pq5RrGAUzslogydrzxLpDDN BgWolP4wzTaxiO7HxlOrIpE4bkTwrfVPqDLAqd0y2TKJfcX3bgPW1YzdG8cFawp+SjUz xshphhCN5UwV8wkUArs3Eo8/ODzUyQq6klyPzQ6YkudA5v7kV1+YuCCC57a2de+OcfWa gCOg== X-Gm-Message-State: AJIora8M/96yyyTWZ5BUYFlZ4OpjICj2EbjEvVMWvDChebL9yrDh51G7 xe7z7ALx3S+s869wLdg0/2mCAQ== X-Google-Smtp-Source: AGRyM1vNNODoy68cNcew+BOwykVJS5AyiEbndqdKVVh3DpwTH+wUBJ1HcGxnO6zSsyx2Hva19xbd8w== X-Received: by 2002:a17:90b:3b52:b0:1ec:db2a:b946 with SMTP id ot18-20020a17090b3b5200b001ecdb2ab946mr838564pjb.229.1656438899502; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id f15-20020a170902ff0f00b0016a84d232a6sm5432810plj.46.2022.06.28.10.54.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Date: Tue, 28 Jun 2022 10:54:58 -0700 From: Kees Cook To: Jason Gunthorpe Cc: Daniel Borkmann , "Gustavo A. R. Silva" , linux-kernel@vger.kernel.org, x86@kernel.org, dm-devel@redhat.com, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-can@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux1394-devel@lists.sourceforge.net, io-uring@vger.kernel.org, lvs-devel@vger.kernel.org, linux-mtd@lists.infradead.org, kasan-dev@googlegroups.com, linux-mmc@vger.kernel.org, nvdimm@lists.linux.dev, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-perf-users@vger.kernel.org, linux-raid@vger.kernel.org, linux-sctp@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, v9fs-developer@lists.sourceforge.net, linux-rdma@vger.kernel.org, alsa-devel@alsa-project.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Message-ID: <202206281009.4332AA33@keescook> References: <20220627180432.GA136081@embeddedor> <6bc1e94c-ce1d-a074-7d0c-8dbe6ce22637@iogearbox.net> <20220628004052.GM23621@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220628004052.GM23621@ziepe.ca> Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Mon, Jun 27, 2022 at 09:40:52PM -0300, Jason Gunthorpe wrote: > On Mon, Jun 27, 2022 at 08:27:37PM +0200, Daniel Borkmann wrote: > > [...] > > Fyi, this breaks BPF CI: > > > > https://github.com/kernel-patches/bpf/runs/7078719372?check_suite_focus=true > > > > [...] > > progs/map_ptr_kern.c:314:26: error: field 'trie_key' with variable sized type 'struct bpf_lpm_trie_key' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > > struct bpf_lpm_trie_key trie_key; > > ^ The issue here seems to be a collision between "unknown array size" and known sizes: struct bpf_lpm_trie_key { __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ __u8 data[0]; /* Arbitrary size */ }; struct lpm_key { struct bpf_lpm_trie_key trie_key; __u32 data; }; This is treating trie_key as a header, which it's not: it's a complete structure. :) Perhaps: struct lpm_key { __u32 prefixlen; __u32 data; }; I don't see anything else trying to include bpf_lpm_trie_key. > > This will break the rdma-core userspace as well, with a similar > error: > > /usr/bin/clang-13 -DVERBS_DEBUG -Dibverbs_EXPORTS -Iinclude -I/usr/include/libnl3 -I/usr/include/drm -g -O2 -fdebug-prefix-map=/__w/1/s=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wmissing-prototypes -Wmissing-declarations -Wwrite-strings -Wformat=2 -Wcast-function-type -Wformat-nonliteral -Wdate-time -Wnested-externs -Wshadow -Wstrict-prototypes -Wold-style-definition -Werror -Wredundant-decls -g -fPIC -std=gnu11 -MD -MT libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -MF libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o.d -o libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -c ../libibverbs/cmd_flow.c > In file included from ../libibverbs/cmd_flow.c:33: > In file included from include/infiniband/cmd_write.h:36: > In file included from include/infiniband/cmd_ioctl.h:41: > In file included from include/infiniband/verbs.h:48: > In file included from include/infiniband/verbs_api.h:66: > In file included from include/infiniband/ib_user_ioctl_verbs.h:38: > include/rdma/ib_user_verbs.h:436:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_cq_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_cq_resp base; > ^ > include/rdma/ib_user_verbs.h:644:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_qp_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_qp_resp base; This looks very similar, a struct of unknown size is being treated as a header struct: struct ib_uverbs_create_cq_resp { __u32 cq_handle; __u32 cqe; __aligned_u64 driver_data[0]; }; struct ib_uverbs_ex_create_cq_resp { struct ib_uverbs_create_cq_resp base; __u32 comp_mask; __u32 response_length; }; And it only gets used here: DECLARE_UVERBS_WRITE(IB_USER_VERBS_CMD_CREATE_CQ, ib_uverbs_create_cq, UAPI_DEF_WRITE_UDATA_IO( struct ib_uverbs_create_cq, struct ib_uverbs_create_cq_resp), ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UAPI_DEF_METHOD_NEEDS_FN(create_cq)), which must also be assuming it's a header. So probably better to just drop the driver_data field? I don't see anything using it (that I can find) besides as a sanity-check that the field exists and is at the end of the struct. -- Kees Cook 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 us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BE3D9CCA47E for ; Tue, 28 Jun 2022 17:55:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1656438910; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=s0eaMDOU7P9oUaR+hhTfJiNyu6GfRMLAM1aNwIjPp6c=; b=JYl/LcfAw87W8Sl4a3Oa8Zhs1iYYmIcZq0OIQEivcdyZE2zBm2tFioucvk+3uWaw+5xBn+ W3nIX9iwQKIlCJwbYHwGXw8Ra9qAMinxk5WpxMVwxkYSx5g88NQde6yiOxUdkHjXypVdbx mWtf5I4ukYEhU00SgxcKkWThafaKYkI= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-258-HhZnnMlENgW1_xzKCi2ucw-1; Tue, 28 Jun 2022 13:55:07 -0400 X-MC-Unique: HhZnnMlENgW1_xzKCi2ucw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 857F2101AA4E; Tue, 28 Jun 2022 17:55:05 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (unknown [10.30.29.100]) by smtp.corp.redhat.com (Postfix) with ESMTP id 30DFC40C1289; Tue, 28 Jun 2022 17:55:05 +0000 (UTC) Received: from mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (localhost [IPv6:::1]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id B14AC1947056; Tue, 28 Jun 2022 17:55:04 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx10.intmail.prod.int.rdu2.redhat.com [10.11.54.10]) by mm-prod-listman-01.mail-001.prod.us-east-1.aws.redhat.com (Postfix) with ESMTP id 479F319466DF for ; Tue, 28 Jun 2022 17:55:03 +0000 (UTC) Received: by smtp.corp.redhat.com (Postfix) id 157D741616B; Tue, 28 Jun 2022 17:55:03 +0000 (UTC) Received: from mimecast-mx02.redhat.com (mimecast05.extmail.prod.ext.rdu2.redhat.com [10.11.55.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 10F2C41615A for ; Tue, 28 Jun 2022 17:55:03 +0000 (UTC) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [205.139.110.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id ED32A800971 for ; Tue, 28 Jun 2022 17:55:02 +0000 (UTC) Received: from mail-pj1-f53.google.com (mail-pj1-f53.google.com [209.85.216.53]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-220-zBKeO-vCOrCcbCD_N2zYsg-1; Tue, 28 Jun 2022 13:55:00 -0400 X-MC-Unique: zBKeO-vCOrCcbCD_N2zYsg-1 Received: by mail-pj1-f53.google.com with SMTP id g16-20020a17090a7d1000b001ea9f820449so16701163pjl.5 for ; Tue, 28 Jun 2022 10:55:00 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=ImdZO/7QQwVIMZLwbKsz0e8kitExPkSq17Qn1eK2rbt24DAt3kJcJPWpNxAWzrMNzR sRtf2aBQsPriJ4zpCuvTOWGozQWTlhG/65FzxJN1iWjyvN1huhKHycc0kiK9USMyIOiv gO3lKkw7vR+4pLIdCZmnsQ0FCMXl+TxqygNmJPdMo5hfGNOrZ4wtOknuPvGav1G2/l0n HeMnWhLAb4InW9ugSa1p9drDlrUCoCjKuXehVLTG5TodC0+bKPkJYje8ZPpjGh2O7wLU AGM44ZtbXzvOolRTDf6XWs8bL54azZL0WSj69Om/gmK+pNcRzGeiBXVsKV2If2hsrMA7 /j0g== X-Gm-Message-State: AJIora8zbR6uKuTW63JlUyZWPJTpi7N5JpFgz0v9qHM2qxpfVhwIvtl+ gh+mqsg6xVwJy5v/3p97pVNVwg== X-Google-Smtp-Source: AGRyM1vNNODoy68cNcew+BOwykVJS5AyiEbndqdKVVh3DpwTH+wUBJ1HcGxnO6zSsyx2Hva19xbd8w== X-Received: by 2002:a17:90b:3b52:b0:1ec:db2a:b946 with SMTP id ot18-20020a17090b3b5200b001ecdb2ab946mr838564pjb.229.1656438899502; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id f15-20020a170902ff0f00b0016a84d232a6sm5432810plj.46.2022.06.28.10.54.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Date: Tue, 28 Jun 2022 10:54:58 -0700 From: Kees Cook To: Jason Gunthorpe Message-ID: <202206281009.4332AA33@keescook> References: <20220627180432.GA136081@embeddedor> <6bc1e94c-ce1d-a074-7d0c-8dbe6ce22637@iogearbox.net> <20220628004052.GM23621@ziepe.ca> MIME-Version: 1.0 In-Reply-To: <20220628004052.GM23621@ziepe.ca> X-Mimecast-Impersonation-Protect: Policy=CLT - Impersonation Protection Definition; Similar Internal Domain=false; Similar Monitored External Domain=false; Custom External Domain=false; Mimecast External Domain=false; Newly Observed Domain=false; Internal User Name=false; Custom Display Name List=false; Reply-to Address Mismatch=false; Targeted Threat Dictionary=false; Mimecast Threat Dictionary=false; Custom Threat Dictionary=false X-Scanned-By: MIMEDefang 2.85 on 10.11.54.10 Subject: Re: [dm-devel] [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nvdimm@lists.linux.dev, alsa-devel@alsa-project.org, kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, "Gustavo A. R. Silva" , dm-devel@redhat.com, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-hardening@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-stm32@st-md-mailman.stormreply.com, linux-s390@vger.kernel.org, Daniel Borkmann , linux-rdma@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, lvs-devel@vger.kernel.org, coreteam@netfilter.org, v9fs-developer@lists.sourceforge.net, linux-mips@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-can@vger.kernel.org, linux-raid@vger.kernel.org, linux-m68k@lists.linux-m68k.org, virtualization@lists.linux-foundation.org, io-uring@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-sctp@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org Errors-To: dm-devel-bounces@redhat.com Sender: "dm-devel" X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Mon, Jun 27, 2022 at 09:40:52PM -0300, Jason Gunthorpe wrote: > On Mon, Jun 27, 2022 at 08:27:37PM +0200, Daniel Borkmann wrote: > > [...] > > Fyi, this breaks BPF CI: > > > > https://github.com/kernel-patches/bpf/runs/7078719372?check_suite_focus=true > > > > [...] > > progs/map_ptr_kern.c:314:26: error: field 'trie_key' with variable sized type 'struct bpf_lpm_trie_key' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > > struct bpf_lpm_trie_key trie_key; > > ^ The issue here seems to be a collision between "unknown array size" and known sizes: struct bpf_lpm_trie_key { __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ __u8 data[0]; /* Arbitrary size */ }; struct lpm_key { struct bpf_lpm_trie_key trie_key; __u32 data; }; This is treating trie_key as a header, which it's not: it's a complete structure. :) Perhaps: struct lpm_key { __u32 prefixlen; __u32 data; }; I don't see anything else trying to include bpf_lpm_trie_key. > > This will break the rdma-core userspace as well, with a similar > error: > > /usr/bin/clang-13 -DVERBS_DEBUG -Dibverbs_EXPORTS -Iinclude -I/usr/include/libnl3 -I/usr/include/drm -g -O2 -fdebug-prefix-map=/__w/1/s=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wmissing-prototypes -Wmissing-declarations -Wwrite-strings -Wformat=2 -Wcast-function-type -Wformat-nonliteral -Wdate-time -Wnested-externs -Wshadow -Wstrict-prototypes -Wold-style-definition -Werror -Wredundant-decls -g -fPIC -std=gnu11 -MD -MT libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -MF libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o.d -o libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -c ../libibverbs/cmd_flow.c > In file included from ../libibverbs/cmd_flow.c:33: > In file included from include/infiniband/cmd_write.h:36: > In file included from include/infiniband/cmd_ioctl.h:41: > In file included from include/infiniband/verbs.h:48: > In file included from include/infiniband/verbs_api.h:66: > In file included from include/infiniband/ib_user_ioctl_verbs.h:38: > include/rdma/ib_user_verbs.h:436:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_cq_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_cq_resp base; > ^ > include/rdma/ib_user_verbs.h:644:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_qp_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_qp_resp base; This looks very similar, a struct of unknown size is being treated as a header struct: struct ib_uverbs_create_cq_resp { __u32 cq_handle; __u32 cqe; __aligned_u64 driver_data[0]; }; struct ib_uverbs_ex_create_cq_resp { struct ib_uverbs_create_cq_resp base; __u32 comp_mask; __u32 response_length; }; And it only gets used here: DECLARE_UVERBS_WRITE(IB_USER_VERBS_CMD_CREATE_CQ, ib_uverbs_create_cq, UAPI_DEF_WRITE_UDATA_IO( struct ib_uverbs_create_cq, struct ib_uverbs_create_cq_resp), ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UAPI_DEF_METHOD_NEEDS_FN(create_cq)), which must also be assuming it's a header. So probably better to just drop the driver_data field? I don't see anything using it (that I can find) besides as a sanity-check that the field exists and is at the end of the struct. -- Kees Cook -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id B2645C433EF for ; Tue, 28 Jun 2022 17:55:01 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 1C9B2113DC2; Tue, 28 Jun 2022 17:55:01 +0000 (UTC) Received: from mail-pj1-x1036.google.com (mail-pj1-x1036.google.com [IPv6:2607:f8b0:4864:20::1036]) by gabe.freedesktop.org (Postfix) with ESMTPS id E4F9C11B499 for ; Tue, 28 Jun 2022 17:54:59 +0000 (UTC) Received: by mail-pj1-x1036.google.com with SMTP id g16-20020a17090a7d1000b001ea9f820449so16701166pjl.5 for ; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=Lpc3rw2lUDFTgNuiFkNi7vJ3FOoQQ8sPNV+A/xT7kPgFFi5TelrrdXlIUbrL4j9GT+ 3+ei8DuymmFwmq4TMtVSFXVwj/BEoFuIu2AqPN9i6R5zOS+ndUs4OIvpg1Fj2tZP3rAs mZTqNdFC15vlNUFmjWu7inrraPu1BA3Mkzqts= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=CFBVXIjy5OOBX/ImIUDSqsyN3rvI1xwBxvr6Sqcl0vGZHBH+JR7ixQbIL3oqgDH+O9 1+ZFAKKcn5bKYqCkiCluR379Pggdz/XaC72w1B9tUUNS4BRcM19C8SQTAUn4yispgb1P fGEUMfBMjpIupuTaiB1ASA0nlr2TjcCCNhK0KB1wYEPTs0tRfquI7qf3UkUHNgRPeOuE rrzkgq9HfUoEoji64QGJt5nH/dsRb7kgEY/ErqgCtfWM+tSYNrQmYpiItgdvWO01ApU3 Tq0b/5po7MdS/aF1DkKmx28XpuqXZ3Nf9TgUEg7tX3tonbk5ghU8EKynaV/vX9cOKb5l TYTA== X-Gm-Message-State: AJIora+Ib2w7OmRr/EBpjr/Y/FsURdSfCwEcZ+beqPkfikr+IX0BXH1J Qhoxkz/9J9WydW93OexjVMD4Bg== X-Google-Smtp-Source: AGRyM1vNNODoy68cNcew+BOwykVJS5AyiEbndqdKVVh3DpwTH+wUBJ1HcGxnO6zSsyx2Hva19xbd8w== X-Received: by 2002:a17:90b:3b52:b0:1ec:db2a:b946 with SMTP id ot18-20020a17090b3b5200b001ecdb2ab946mr838564pjb.229.1656438899502; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id f15-20020a170902ff0f00b0016a84d232a6sm5432810plj.46.2022.06.28.10.54.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Date: Tue, 28 Jun 2022 10:54:58 -0700 From: Kees Cook To: Jason Gunthorpe Message-ID: <202206281009.4332AA33@keescook> References: <20220627180432.GA136081@embeddedor> <6bc1e94c-ce1d-a074-7d0c-8dbe6ce22637@iogearbox.net> <20220628004052.GM23621@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220628004052.GM23621@ziepe.ca> Subject: Re: [Intel-gfx] [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nvdimm@lists.linux.dev, alsa-devel@alsa-project.org, kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, "Gustavo A. R. Silva" , dm-devel@redhat.com, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-hardening@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-stm32@st-md-mailman.stormreply.com, linux-s390@vger.kernel.org, Daniel Borkmann , linux-rdma@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, lvs-devel@vger.kernel.org, coreteam@netfilter.org, v9fs-developer@lists.sourceforge.net, linux-mips@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-can@vger.kernel.org, linux-raid@vger.kernel.org, linux-m68k@lists.linux-m68k.org, virtualization@lists.linux-foundation.org, io-uring@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-sctp@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Mon, Jun 27, 2022 at 09:40:52PM -0300, Jason Gunthorpe wrote: > On Mon, Jun 27, 2022 at 08:27:37PM +0200, Daniel Borkmann wrote: > > [...] > > Fyi, this breaks BPF CI: > > > > https://github.com/kernel-patches/bpf/runs/7078719372?check_suite_focus=true > > > > [...] > > progs/map_ptr_kern.c:314:26: error: field 'trie_key' with variable sized type 'struct bpf_lpm_trie_key' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > > struct bpf_lpm_trie_key trie_key; > > ^ The issue here seems to be a collision between "unknown array size" and known sizes: struct bpf_lpm_trie_key { __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ __u8 data[0]; /* Arbitrary size */ }; struct lpm_key { struct bpf_lpm_trie_key trie_key; __u32 data; }; This is treating trie_key as a header, which it's not: it's a complete structure. :) Perhaps: struct lpm_key { __u32 prefixlen; __u32 data; }; I don't see anything else trying to include bpf_lpm_trie_key. > > This will break the rdma-core userspace as well, with a similar > error: > > /usr/bin/clang-13 -DVERBS_DEBUG -Dibverbs_EXPORTS -Iinclude -I/usr/include/libnl3 -I/usr/include/drm -g -O2 -fdebug-prefix-map=/__w/1/s=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wmissing-prototypes -Wmissing-declarations -Wwrite-strings -Wformat=2 -Wcast-function-type -Wformat-nonliteral -Wdate-time -Wnested-externs -Wshadow -Wstrict-prototypes -Wold-style-definition -Werror -Wredundant-decls -g -fPIC -std=gnu11 -MD -MT libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -MF libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o.d -o libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -c ../libibverbs/cmd_flow.c > In file included from ../libibverbs/cmd_flow.c:33: > In file included from include/infiniband/cmd_write.h:36: > In file included from include/infiniband/cmd_ioctl.h:41: > In file included from include/infiniband/verbs.h:48: > In file included from include/infiniband/verbs_api.h:66: > In file included from include/infiniband/ib_user_ioctl_verbs.h:38: > include/rdma/ib_user_verbs.h:436:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_cq_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_cq_resp base; > ^ > include/rdma/ib_user_verbs.h:644:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_qp_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_qp_resp base; This looks very similar, a struct of unknown size is being treated as a header struct: struct ib_uverbs_create_cq_resp { __u32 cq_handle; __u32 cqe; __aligned_u64 driver_data[0]; }; struct ib_uverbs_ex_create_cq_resp { struct ib_uverbs_create_cq_resp base; __u32 comp_mask; __u32 response_length; }; And it only gets used here: DECLARE_UVERBS_WRITE(IB_USER_VERBS_CMD_CREATE_CQ, ib_uverbs_create_cq, UAPI_DEF_WRITE_UDATA_IO( struct ib_uverbs_create_cq, struct ib_uverbs_create_cq_resp), ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UAPI_DEF_METHOD_NEEDS_FN(create_cq)), which must also be assuming it's a header. So probably better to just drop the driver_data field? I don't see anything using it (that I can find) besides as a sanity-check that the field exists and is at the end of the struct. -- Kees Cook 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D7BC4C43334 for ; Tue, 28 Jun 2022 17:55:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=Fc1ftk0V08by/sPHZLuX3xQazA9BaBzx7D9wFDrlcuE=; b=sp1ddtFYAchQUx UXdaAFZ/Y8nVZmwWZQDMlY9MpSkc2FXDMffCkmORFnicze8FXBDdtKh3pYlPBrP3HV4EwFT9yVNrz 2qmd/fVh4EMvsc0TC8Kw0XPfXy7xrZH60j9cywv8T10pfygEjM0eXOwopth5DawnnQHNdBD4BzhBT lAdBxTSZNVS61upov11XVr8zDewDABBpEU75wAmID3iPz0AJLxKy2N5XOp2j7XphjoJwFLzHfp2Sc 4MYvLq1RALpdUKqP2qTvCuOWp0VgV4DvzTzj+W+IS0vveRKXPAk0utuhaqEVvRRAMAGOseHSUq18Y ZIHeLJLJKFDNMtOY3TrQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o6FQZ-007Txr-E0; Tue, 28 Jun 2022 17:55:07 +0000 Received: from mail-pl1-x635.google.com ([2607:f8b0:4864:20::635]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o6FQV-007Ttt-QW for linux-mtd@lists.infradead.org; Tue, 28 Jun 2022 17:55:05 +0000 Received: by mail-pl1-x635.google.com with SMTP id c4so11735275plc.8 for ; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=Lpc3rw2lUDFTgNuiFkNi7vJ3FOoQQ8sPNV+A/xT7kPgFFi5TelrrdXlIUbrL4j9GT+ 3+ei8DuymmFwmq4TMtVSFXVwj/BEoFuIu2AqPN9i6R5zOS+ndUs4OIvpg1Fj2tZP3rAs mZTqNdFC15vlNUFmjWu7inrraPu1BA3Mkzqts= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=H4Br37hzk/phnF9laMIIXq0koWYbG6wzJssWT/LuLLUwEn/6Z8kJFgaeNR6g6ngMW2 MYYLMHZ0HYx+QavYiLXK+zXOqIYtURIh4xlb6EZXRhYdHqE8AJrDt6Xf7jifDuRpNqXI tNDhwadhv0tCAa5xNnv0jjweidt+gRBuTP4y5MvS9dYXMePLKlwe1SxiwW4XhTEWmSrg agNbtWCoWwmx0qp2q/sqQYh+rndvlf39fYWe/3HC0q6VJopyEohACLjrLFMfcT2Qw4Un GrIQG49mUUSTSJRqlNyKRhGZz74Y/Ab15XiJGdUhh/+R64fCO/esoDoENPZx0mszx2Dn LaJQ== X-Gm-Message-State: AJIora8jji0T0YywDVZvlf9oBA+nra1etQo0RgOuVsRbQB2gwbjGHX/1 RRJaC27zFTdsejtapEdXtaqeIA== X-Google-Smtp-Source: AGRyM1vNNODoy68cNcew+BOwykVJS5AyiEbndqdKVVh3DpwTH+wUBJ1HcGxnO6zSsyx2Hva19xbd8w== X-Received: by 2002:a17:90b:3b52:b0:1ec:db2a:b946 with SMTP id ot18-20020a17090b3b5200b001ecdb2ab946mr838564pjb.229.1656438899502; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id f15-20020a170902ff0f00b0016a84d232a6sm5432810plj.46.2022.06.28.10.54.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Date: Tue, 28 Jun 2022 10:54:58 -0700 From: Kees Cook To: Jason Gunthorpe Cc: Daniel Borkmann , "Gustavo A. R. Silva" , linux-kernel@vger.kernel.org, x86@kernel.org, dm-devel@redhat.com, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-can@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux1394-devel@lists.sourceforge.net, io-uring@vger.kernel.org, lvs-devel@vger.kernel.org, linux-mtd@lists.infradead.org, kasan-dev@googlegroups.com, linux-mmc@vger.kernel.org, nvdimm@lists.linux.dev, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-perf-users@vger.kernel.org, linux-raid@vger.kernel.org, linux-sctp@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, v9fs-developer@lists.sourceforge.net, linux-rdma@vger.kernel.org, alsa-devel@alsa-project.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Message-ID: <202206281009.4332AA33@keescook> References: <20220627180432.GA136081@embeddedor> <6bc1e94c-ce1d-a074-7d0c-8dbe6ce22637@iogearbox.net> <20220628004052.GM23621@ziepe.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220628004052.GM23621@ziepe.ca> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220628_105503_892154_E84FD58C X-CRM114-Status: GOOD ( 16.71 ) X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-mtd" Errors-To: linux-mtd-bounces+linux-mtd=archiver.kernel.org@lists.infradead.org On Mon, Jun 27, 2022 at 09:40:52PM -0300, Jason Gunthorpe wrote: > On Mon, Jun 27, 2022 at 08:27:37PM +0200, Daniel Borkmann wrote: > > [...] > > Fyi, this breaks BPF CI: > > > > https://github.com/kernel-patches/bpf/runs/7078719372?check_suite_focus=true > > > > [...] > > progs/map_ptr_kern.c:314:26: error: field 'trie_key' with variable sized type 'struct bpf_lpm_trie_key' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > > struct bpf_lpm_trie_key trie_key; > > ^ The issue here seems to be a collision between "unknown array size" and known sizes: struct bpf_lpm_trie_key { __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ __u8 data[0]; /* Arbitrary size */ }; struct lpm_key { struct bpf_lpm_trie_key trie_key; __u32 data; }; This is treating trie_key as a header, which it's not: it's a complete structure. :) Perhaps: struct lpm_key { __u32 prefixlen; __u32 data; }; I don't see anything else trying to include bpf_lpm_trie_key. > > This will break the rdma-core userspace as well, with a similar > error: > > /usr/bin/clang-13 -DVERBS_DEBUG -Dibverbs_EXPORTS -Iinclude -I/usr/include/libnl3 -I/usr/include/drm -g -O2 -fdebug-prefix-map=/__w/1/s=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wmissing-prototypes -Wmissing-declarations -Wwrite-strings -Wformat=2 -Wcast-function-type -Wformat-nonliteral -Wdate-time -Wnested-externs -Wshadow -Wstrict-prototypes -Wold-style-definition -Werror -Wredundant-decls -g -fPIC -std=gnu11 -MD -MT libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -MF libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o.d -o libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -c ../libibverbs/cmd_flow.c > In file included from ../libibverbs/cmd_flow.c:33: > In file included from include/infiniband/cmd_write.h:36: > In file included from include/infiniband/cmd_ioctl.h:41: > In file included from include/infiniband/verbs.h:48: > In file included from include/infiniband/verbs_api.h:66: > In file included from include/infiniband/ib_user_ioctl_verbs.h:38: > include/rdma/ib_user_verbs.h:436:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_cq_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_cq_resp base; > ^ > include/rdma/ib_user_verbs.h:644:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_qp_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_qp_resp base; This looks very similar, a struct of unknown size is being treated as a header struct: struct ib_uverbs_create_cq_resp { __u32 cq_handle; __u32 cqe; __aligned_u64 driver_data[0]; }; struct ib_uverbs_ex_create_cq_resp { struct ib_uverbs_create_cq_resp base; __u32 comp_mask; __u32 response_length; }; And it only gets used here: DECLARE_UVERBS_WRITE(IB_USER_VERBS_CMD_CREATE_CQ, ib_uverbs_create_cq, UAPI_DEF_WRITE_UDATA_IO( struct ib_uverbs_create_cq, struct ib_uverbs_create_cq_resp), ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UAPI_DEF_METHOD_NEEDS_FN(create_cq)), which must also be assuming it's a header. So probably better to just drop the driver_data field? I don't see anything using it (that I can find) besides as a sanity-check that the field exists and is at the end of the struct. -- Kees Cook ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kees Cook Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Date: Tue, 28 Jun 2022 10:54:58 -0700 Message-ID: <202206281009.4332AA33@keescook> References: <20220627180432.GA136081@embeddedor> <6bc1e94c-ce1d-a074-7d0c-8dbe6ce22637@iogearbox.net> <20220628004052.GM23621@ziepe.ca> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=Lpc3rw2lUDFTgNuiFkNi7vJ3FOoQQ8sPNV+A/xT7kPgFFi5TelrrdXlIUbrL4j9GT+ 3+ei8DuymmFwmq4TMtVSFXVwj/BEoFuIu2AqPN9i6R5zOS+ndUs4OIvpg1Fj2tZP3rAs mZTqNdFC15vlNUFmjWu7inrraPu1BA3Mkzqts= Content-Disposition: inline In-Reply-To: <20220628004052.GM23621@ziepe.ca> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Jason Gunthorpe Cc: nvdimm@lists.linux.dev, alsa-devel@alsa-project.org, kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, "Gustavo A. R. Silva" , dm-devel@redhat.com, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-hardening@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-stm32@st-md-mailman.stormreply.com, linux-s390@vger.kernel.org, Daniel Borkmann , linux-rdma@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, lvs-devel@vger.kernel.org, coreteam@netfilter.org, v9fs-developer@lists.sourceforge.net, linux-mips@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-can@vger.kernel.org, linux-raid@vger.kernel.org, linux-m68k@lists.linux-m68k.org, virtualization@lists.linux-foundation.org, io-uring@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.o On Mon, Jun 27, 2022 at 09:40:52PM -0300, Jason Gunthorpe wrote: > On Mon, Jun 27, 2022 at 08:27:37PM +0200, Daniel Borkmann wrote: > > [...] > > Fyi, this breaks BPF CI: > > > > https://github.com/kernel-patches/bpf/runs/7078719372?check_suite_focus=true > > > > [...] > > progs/map_ptr_kern.c:314:26: error: field 'trie_key' with variable sized type 'struct bpf_lpm_trie_key' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > > struct bpf_lpm_trie_key trie_key; > > ^ The issue here seems to be a collision between "unknown array size" and known sizes: struct bpf_lpm_trie_key { __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ __u8 data[0]; /* Arbitrary size */ }; struct lpm_key { struct bpf_lpm_trie_key trie_key; __u32 data; }; This is treating trie_key as a header, which it's not: it's a complete structure. :) Perhaps: struct lpm_key { __u32 prefixlen; __u32 data; }; I don't see anything else trying to include bpf_lpm_trie_key. > > This will break the rdma-core userspace as well, with a similar > error: > > /usr/bin/clang-13 -DVERBS_DEBUG -Dibverbs_EXPORTS -Iinclude -I/usr/include/libnl3 -I/usr/include/drm -g -O2 -fdebug-prefix-map=/__w/1/s=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wmissing-prototypes -Wmissing-declarations -Wwrite-strings -Wformat=2 -Wcast-function-type -Wformat-nonliteral -Wdate-time -Wnested-externs -Wshadow -Wstrict-prototypes -Wold-style-definition -Werror -Wredundant-decls -g -fPIC -std=gnu11 -MD -MT libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -MF libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o.d -o libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -c ../libibverbs/cmd_flow.c > In file included from ../libibverbs/cmd_flow.c:33: > In file included from include/infiniband/cmd_write.h:36: > In file included from include/infiniband/cmd_ioctl.h:41: > In file included from include/infiniband/verbs.h:48: > In file included from include/infiniband/verbs_api.h:66: > In file included from include/infiniband/ib_user_ioctl_verbs.h:38: > include/rdma/ib_user_verbs.h:436:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_cq_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_cq_resp base; > ^ > include/rdma/ib_user_verbs.h:644:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_qp_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_qp_resp base; This looks very similar, a struct of unknown size is being treated as a header struct: struct ib_uverbs_create_cq_resp { __u32 cq_handle; __u32 cqe; __aligned_u64 driver_data[0]; }; struct ib_uverbs_ex_create_cq_resp { struct ib_uverbs_create_cq_resp base; __u32 comp_mask; __u32 response_length; }; And it only gets used here: DECLARE_UVERBS_WRITE(IB_USER_VERBS_CMD_CREATE_CQ, ib_uverbs_create_cq, UAPI_DEF_WRITE_UDATA_IO( struct ib_uverbs_create_cq, struct ib_uverbs_create_cq_resp), ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UAPI_DEF_METHOD_NEEDS_FN(create_cq)), which must also be assuming it's a header. So probably better to just drop the driver_data field? I don't see anything using it (that I can find) besides as a sanity-check that the field exists and is at the end of the struct. -- Kees Cook 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 smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E8A15CCA481 for ; Tue, 28 Jun 2022 17:55:05 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id 6EA944197F; Tue, 28 Jun 2022 17:55:05 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 6EA944197F Authentication-Results: smtp4.osuosl.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=Lpc3rw2l X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id Rxmzg9aJG_1n; Tue, 28 Jun 2022 17:55:04 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp4.osuosl.org (Postfix) with ESMTPS id 79FA1410AD; Tue, 28 Jun 2022 17:55:03 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 79FA1410AD Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 4A590C0032; Tue, 28 Jun 2022 17:55:03 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 44614C002D for ; Tue, 28 Jun 2022 17:55:01 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id 1EDDB83DEF for ; Tue, 28 Jun 2022 17:55:01 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 1EDDB83DEF Authentication-Results: smtp1.osuosl.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=Lpc3rw2l X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id hv6N8SB5O2dR for ; Tue, 28 Jun 2022 17:55:00 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org 1C2D08348C Received: from mail-pl1-x631.google.com (mail-pl1-x631.google.com [IPv6:2607:f8b0:4864:20::631]) by smtp1.osuosl.org (Postfix) with ESMTPS id 1C2D08348C for ; Tue, 28 Jun 2022 17:55:00 +0000 (UTC) Received: by mail-pl1-x631.google.com with SMTP id l6so11724324plg.11 for ; Tue, 28 Jun 2022 10:55:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=Lpc3rw2lUDFTgNuiFkNi7vJ3FOoQQ8sPNV+A/xT7kPgFFi5TelrrdXlIUbrL4j9GT+ 3+ei8DuymmFwmq4TMtVSFXVwj/BEoFuIu2AqPN9i6R5zOS+ndUs4OIvpg1Fj2tZP3rAs mZTqNdFC15vlNUFmjWu7inrraPu1BA3Mkzqts= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=OzEH7EsWkUXdno5R8Zh5PMI6jXMYQ7PrbYjqNz5T/0XyTm7tV8wisgStBsYOx23VBe fmxxVknq/7HSgY9WYHcqLzLyH5PqwSstCziRi/5AffXzWhgot643oHhzQ+ISohRdYhtX dyIB+Ht3an6rfVb3hrja0QoRmwRlvpTf8fJK7DqUDsy+r8Z0gZxRmLtKfH++QUNqXIg1 FfZenQt2ZoiIEZPq5CedTCJnL/o2tPrlv6hFCw5xNWUGgqIAFWITJ0DJBn7JHSjV6Te9 /BdgmGj4d2qVRUylaAUthaUwjg1dB0XprRBeDXvlWUnKO9NwOZh0JvZHvIRxPonGg3zn 8COQ== X-Gm-Message-State: AJIora+0W2HLHJ0ShhG78cAyqvgWMb6hka4LOoaNIS1hRcYY76bDuh1P w+jMYFhpFyMiusEfy+z1wzdyug== X-Google-Smtp-Source: AGRyM1vNNODoy68cNcew+BOwykVJS5AyiEbndqdKVVh3DpwTH+wUBJ1HcGxnO6zSsyx2Hva19xbd8w== X-Received: by 2002:a17:90b:3b52:b0:1ec:db2a:b946 with SMTP id ot18-20020a17090b3b5200b001ecdb2ab946mr838564pjb.229.1656438899502; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id f15-20020a170902ff0f00b0016a84d232a6sm5432810plj.46.2022.06.28.10.54.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Date: Tue, 28 Jun 2022 10:54:58 -0700 From: Kees Cook To: Jason Gunthorpe Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Message-ID: <202206281009.4332AA33@keescook> References: <20220627180432.GA136081@embeddedor> <6bc1e94c-ce1d-a074-7d0c-8dbe6ce22637@iogearbox.net> <20220628004052.GM23621@ziepe.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220628004052.GM23621@ziepe.ca> Cc: nvdimm@lists.linux.dev, alsa-devel@alsa-project.org, kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, "Gustavo A. R. Silva" , dm-devel@redhat.com, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-hardening@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-stm32@st-md-mailman.stormreply.com, linux-s390@vger.kernel.org, Daniel Borkmann , linux-rdma@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, lvs-devel@vger.kernel.org, coreteam@netfilter.org, v9fs-developer@lists.sourceforge.net, linux-mips@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-can@vger.kernel.org, linux-raid@vger.kernel.org, linux-m68k@lists.linux-m68k.org, virtualization@lists.linux-foundation.org, io-uring@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-sctp@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" On Mon, Jun 27, 2022 at 09:40:52PM -0300, Jason Gunthorpe wrote: > On Mon, Jun 27, 2022 at 08:27:37PM +0200, Daniel Borkmann wrote: > > [...] > > Fyi, this breaks BPF CI: > > > > https://github.com/kernel-patches/bpf/runs/7078719372?check_suite_focus=true > > > > [...] > > progs/map_ptr_kern.c:314:26: error: field 'trie_key' with variable sized type 'struct bpf_lpm_trie_key' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > > struct bpf_lpm_trie_key trie_key; > > ^ The issue here seems to be a collision between "unknown array size" and known sizes: struct bpf_lpm_trie_key { __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ __u8 data[0]; /* Arbitrary size */ }; struct lpm_key { struct bpf_lpm_trie_key trie_key; __u32 data; }; This is treating trie_key as a header, which it's not: it's a complete structure. :) Perhaps: struct lpm_key { __u32 prefixlen; __u32 data; }; I don't see anything else trying to include bpf_lpm_trie_key. > > This will break the rdma-core userspace as well, with a similar > error: > > /usr/bin/clang-13 -DVERBS_DEBUG -Dibverbs_EXPORTS -Iinclude -I/usr/include/libnl3 -I/usr/include/drm -g -O2 -fdebug-prefix-map=/__w/1/s=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wmissing-prototypes -Wmissing-declarations -Wwrite-strings -Wformat=2 -Wcast-function-type -Wformat-nonliteral -Wdate-time -Wnested-externs -Wshadow -Wstrict-prototypes -Wold-style-definition -Werror -Wredundant-decls -g -fPIC -std=gnu11 -MD -MT libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -MF libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o.d -o libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -c ../libibverbs/cmd_flow.c > In file included from ../libibverbs/cmd_flow.c:33: > In file included from include/infiniband/cmd_write.h:36: > In file included from include/infiniband/cmd_ioctl.h:41: > In file included from include/infiniband/verbs.h:48: > In file included from include/infiniband/verbs_api.h:66: > In file included from include/infiniband/ib_user_ioctl_verbs.h:38: > include/rdma/ib_user_verbs.h:436:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_cq_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_cq_resp base; > ^ > include/rdma/ib_user_verbs.h:644:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_qp_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_qp_resp base; This looks very similar, a struct of unknown size is being treated as a header struct: struct ib_uverbs_create_cq_resp { __u32 cq_handle; __u32 cqe; __aligned_u64 driver_data[0]; }; struct ib_uverbs_ex_create_cq_resp { struct ib_uverbs_create_cq_resp base; __u32 comp_mask; __u32 response_length; }; And it only gets used here: DECLARE_UVERBS_WRITE(IB_USER_VERBS_CMD_CREATE_CQ, ib_uverbs_create_cq, UAPI_DEF_WRITE_UDATA_IO( struct ib_uverbs_create_cq, struct ib_uverbs_create_cq_resp), ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UAPI_DEF_METHOD_NEEDS_FN(create_cq)), which must also be assuming it's a header. So probably better to just drop the driver_data field? I don't see anything using it (that I can find) besides as a sanity-check that the field exists and is at the end of the struct. -- Kees Cook _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2F2EBC433EF for ; Tue, 28 Jun 2022 17:56:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=pZOvne3g3E4NUpzbGo5UnQaaWqV4pHpWjnPO750gcrk=; b=HQOCdBeGtqYIsM 7ugMYj4UAM4S5v7lB5ZVY5M8gIWQ3yT+Sh+TyjGAd3/OHs/6D6vKUM/HGlwopnFCgvUtQFF56+ZaY w9pl+MWdO9Cv4jniEYhcZ3u3Mk2RLhvdfFmZf6Hqdk6S385LeZV08pt7+HE8ihbmrmKoj6TWhupmW uZPfICxVJAIvvb+UnmTx0WtFT6gKV+lj5Zi7S8SIgvPe/pWf5H4tCcLUedCV2G2Iu8j4rdfeb6/7B yNyN3MbnRP5S3F7DUmER45SNYZnSpK8flaKni1Ne8OBl6xODX1vACgFbn23Yi43CHAMKEsIyOARlS 9rISfVDct6K+/5EQHcrw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o6FQb-007TyV-Hs; Tue, 28 Jun 2022 17:55:09 +0000 Received: from mail-pj1-x1030.google.com ([2607:f8b0:4864:20::1030]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1o6FQV-007Ttu-RG for linux-arm-kernel@lists.infradead.org; Tue, 28 Jun 2022 17:55:05 +0000 Received: by mail-pj1-x1030.google.com with SMTP id w19-20020a17090a8a1300b001ec79064d8dso16720257pjn.2 for ; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=Lpc3rw2lUDFTgNuiFkNi7vJ3FOoQQ8sPNV+A/xT7kPgFFi5TelrrdXlIUbrL4j9GT+ 3+ei8DuymmFwmq4TMtVSFXVwj/BEoFuIu2AqPN9i6R5zOS+ndUs4OIvpg1Fj2tZP3rAs mZTqNdFC15vlNUFmjWu7inrraPu1BA3Mkzqts= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=RwnxwF5wBAFHXFF9rB3eGQTH6bhAE0he6Ba6eoU/vWu2Wn5JkZift8aTIRR0hsAiuw yCLsuOmPl26luvS1gEjmVuN7ZG3pNh9yK4D07u3Sdu2xBZGOf3LZSF1T/wkuRemp/Jwn wiYjirVeVass0wpFRNISriqD8QWHbjvNaBXSkRIl/znVk8S0v6eBzp4sEAEtTgoPD4kd 4qRg0dg7OIZKzDzFjlnWMC6kTvtkeKhXBCOgAHLQInxwCY9FNwwyA+uMChUxH5Q3iBnP V15FZMgH/NUvHYbp12QDsFneEKunTgvPZ6ASdp6wyNs8TkceUPz/trWJjGG1jUMuJQEq OVIQ== X-Gm-Message-State: AJIora8URjubAsJIHB6gOfcky6TBOsV/+Bg+TpwRzmOG77rPIbXWVWW1 HgUqvM9PwFdLCuqlB5BXhs7G3g== X-Google-Smtp-Source: AGRyM1vNNODoy68cNcew+BOwykVJS5AyiEbndqdKVVh3DpwTH+wUBJ1HcGxnO6zSsyx2Hva19xbd8w== X-Received: by 2002:a17:90b:3b52:b0:1ec:db2a:b946 with SMTP id ot18-20020a17090b3b5200b001ecdb2ab946mr838564pjb.229.1656438899502; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id f15-20020a170902ff0f00b0016a84d232a6sm5432810plj.46.2022.06.28.10.54.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Date: Tue, 28 Jun 2022 10:54:58 -0700 From: Kees Cook To: Jason Gunthorpe Cc: Daniel Borkmann , "Gustavo A. R. Silva" , linux-kernel@vger.kernel.org, x86@kernel.org, dm-devel@redhat.com, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-can@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux1394-devel@lists.sourceforge.net, io-uring@vger.kernel.org, lvs-devel@vger.kernel.org, linux-mtd@lists.infradead.org, kasan-dev@googlegroups.com, linux-mmc@vger.kernel.org, nvdimm@lists.linux.dev, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, linux-perf-users@vger.kernel.org, linux-raid@vger.kernel.org, linux-sctp@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, target-devel@vger.kernel.org, linux-usb@vger.kernel.org, virtualization@lists.linux-foundation.org, v9fs-developer@lists.sourceforge.net, linux-rdma@vger.kernel.org, alsa-devel@alsa-project.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Message-ID: <202206281009.4332AA33@keescook> References: <20220627180432.GA136081@embeddedor> <6bc1e94c-ce1d-a074-7d0c-8dbe6ce22637@iogearbox.net> <20220628004052.GM23621@ziepe.ca> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220628004052.GM23621@ziepe.ca> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220628_105503_889679_9303AF8C X-CRM114-Status: GOOD ( 17.50 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Jun 27, 2022 at 09:40:52PM -0300, Jason Gunthorpe wrote: > On Mon, Jun 27, 2022 at 08:27:37PM +0200, Daniel Borkmann wrote: > > [...] > > Fyi, this breaks BPF CI: > > > > https://github.com/kernel-patches/bpf/runs/7078719372?check_suite_focus=true > > > > [...] > > progs/map_ptr_kern.c:314:26: error: field 'trie_key' with variable sized type 'struct bpf_lpm_trie_key' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > > struct bpf_lpm_trie_key trie_key; > > ^ The issue here seems to be a collision between "unknown array size" and known sizes: struct bpf_lpm_trie_key { __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ __u8 data[0]; /* Arbitrary size */ }; struct lpm_key { struct bpf_lpm_trie_key trie_key; __u32 data; }; This is treating trie_key as a header, which it's not: it's a complete structure. :) Perhaps: struct lpm_key { __u32 prefixlen; __u32 data; }; I don't see anything else trying to include bpf_lpm_trie_key. > > This will break the rdma-core userspace as well, with a similar > error: > > /usr/bin/clang-13 -DVERBS_DEBUG -Dibverbs_EXPORTS -Iinclude -I/usr/include/libnl3 -I/usr/include/drm -g -O2 -fdebug-prefix-map=/__w/1/s=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wmissing-prototypes -Wmissing-declarations -Wwrite-strings -Wformat=2 -Wcast-function-type -Wformat-nonliteral -Wdate-time -Wnested-externs -Wshadow -Wstrict-prototypes -Wold-style-definition -Werror -Wredundant-decls -g -fPIC -std=gnu11 -MD -MT libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -MF libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o.d -o libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -c ../libibverbs/cmd_flow.c > In file included from ../libibverbs/cmd_flow.c:33: > In file included from include/infiniband/cmd_write.h:36: > In file included from include/infiniband/cmd_ioctl.h:41: > In file included from include/infiniband/verbs.h:48: > In file included from include/infiniband/verbs_api.h:66: > In file included from include/infiniband/ib_user_ioctl_verbs.h:38: > include/rdma/ib_user_verbs.h:436:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_cq_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_cq_resp base; > ^ > include/rdma/ib_user_verbs.h:644:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_qp_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_qp_resp base; This looks very similar, a struct of unknown size is being treated as a header struct: struct ib_uverbs_create_cq_resp { __u32 cq_handle; __u32 cqe; __aligned_u64 driver_data[0]; }; struct ib_uverbs_ex_create_cq_resp { struct ib_uverbs_create_cq_resp base; __u32 comp_mask; __u32 response_length; }; And it only gets used here: DECLARE_UVERBS_WRITE(IB_USER_VERBS_CMD_CREATE_CQ, ib_uverbs_create_cq, UAPI_DEF_WRITE_UDATA_IO( struct ib_uverbs_create_cq, struct ib_uverbs_create_cq_resp), ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UAPI_DEF_METHOD_NEEDS_FN(create_cq)), which must also be assuming it's a header. So probably better to just drop the driver_data field? I don't see anything using it (that I can find) besides as a sanity-check that the field exists and is at the end of the struct. -- Kees Cook _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 37E23C43334 for ; Tue, 28 Jun 2022 17:55:02 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 05FE8113667; Tue, 28 Jun 2022 17:55:01 +0000 (UTC) Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by gabe.freedesktop.org (Postfix) with ESMTPS id E43AB11B495 for ; Tue, 28 Jun 2022 17:54:59 +0000 (UTC) Received: by mail-pj1-x1029.google.com with SMTP id c6-20020a17090abf0600b001eee794a478so6039840pjs.1 for ; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=Lpc3rw2lUDFTgNuiFkNi7vJ3FOoQQ8sPNV+A/xT7kPgFFi5TelrrdXlIUbrL4j9GT+ 3+ei8DuymmFwmq4TMtVSFXVwj/BEoFuIu2AqPN9i6R5zOS+ndUs4OIvpg1Fj2tZP3rAs mZTqNdFC15vlNUFmjWu7inrraPu1BA3Mkzqts= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=Ifakbg1KSXljeCc2KlqlOz+XfzIBohlTVCEx+b5hm2Y=; b=Bz6q2aOs55VSA4rR9ftGKwcSjaklXM0rQ8KR3nbfNnU/S+czI2viugtVrRTpfRyh4R XTtuFQv+QJqfK48RX+y5lPeg8cYjGLXJbkNLfVFtUggyUdbkDUls5nbkqPJd3FSsxoxr VNahQImPlps40KhCcqt/2WOIN2p0P1BNy17cEhaoJ7DS6N80xT4xyV7RO/QYhrp6DlIc cGJil3Az1M16I2L2Cv/YCm7UKZ9ekZm++yrNtoyQ8F4nppnRM+7mdLx1qRNC6P0aONSh Y6yeZ/s6m1I2sFYlSC3h1MU0T0cDMFWgG3BrGAeIYayrbIr9js1UTPBOMeGBzzCEPIQm eU2g== X-Gm-Message-State: AJIora9duzeIynlOXu5AKl0Sx43ZFq6H+gwNy3JBB8uCPR23wCRALgug rJ2rwecOLiOWwgshP0va71jxzw== X-Google-Smtp-Source: AGRyM1vNNODoy68cNcew+BOwykVJS5AyiEbndqdKVVh3DpwTH+wUBJ1HcGxnO6zSsyx2Hva19xbd8w== X-Received: by 2002:a17:90b:3b52:b0:1ec:db2a:b946 with SMTP id ot18-20020a17090b3b5200b001ecdb2ab946mr838564pjb.229.1656438899502; Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id f15-20020a170902ff0f00b0016a84d232a6sm5432810plj.46.2022.06.28.10.54.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Jun 2022 10:54:59 -0700 (PDT) Date: Tue, 28 Jun 2022 10:54:58 -0700 From: Kees Cook To: Jason Gunthorpe Subject: Re: [PATCH][next] treewide: uapi: Replace zero-length arrays with flexible-array members Message-ID: <202206281009.4332AA33@keescook> References: <20220627180432.GA136081@embeddedor> <6bc1e94c-ce1d-a074-7d0c-8dbe6ce22637@iogearbox.net> <20220628004052.GM23621@ziepe.ca> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220628004052.GM23621@ziepe.ca> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: nvdimm@lists.linux.dev, alsa-devel@alsa-project.org, kvm@vger.kernel.org, dri-devel@lists.freedesktop.org, "Gustavo A. R. Silva" , dm-devel@redhat.com, target-devel@vger.kernel.org, linux-mtd@lists.infradead.org, linux-hardening@vger.kernel.org, linux1394-devel@lists.sourceforge.net, linux-stm32@st-md-mailman.stormreply.com, linux-s390@vger.kernel.org, Daniel Borkmann , linux-rdma@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, lvs-devel@vger.kernel.org, coreteam@netfilter.org, v9fs-developer@lists.sourceforge.net, linux-mips@vger.kernel.org, intel-gfx@lists.freedesktop.org, linux-can@vger.kernel.org, linux-raid@vger.kernel.org, linux-m68k@lists.linux-m68k.org, virtualization@lists.linux-foundation.org, io-uring@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-scsi@vger.kernel.org, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-sctp@vger.kernel.org, netfilter-devel@vger.kernel.org, linux-fsdevel@vger.kernel.org, bpf@vger.kernel.org, linux-btrfs@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, Jun 27, 2022 at 09:40:52PM -0300, Jason Gunthorpe wrote: > On Mon, Jun 27, 2022 at 08:27:37PM +0200, Daniel Borkmann wrote: > > [...] > > Fyi, this breaks BPF CI: > > > > https://github.com/kernel-patches/bpf/runs/7078719372?check_suite_focus=true > > > > [...] > > progs/map_ptr_kern.c:314:26: error: field 'trie_key' with variable sized type 'struct bpf_lpm_trie_key' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > > struct bpf_lpm_trie_key trie_key; > > ^ The issue here seems to be a collision between "unknown array size" and known sizes: struct bpf_lpm_trie_key { __u32 prefixlen; /* up to 32 for AF_INET, 128 for AF_INET6 */ __u8 data[0]; /* Arbitrary size */ }; struct lpm_key { struct bpf_lpm_trie_key trie_key; __u32 data; }; This is treating trie_key as a header, which it's not: it's a complete structure. :) Perhaps: struct lpm_key { __u32 prefixlen; __u32 data; }; I don't see anything else trying to include bpf_lpm_trie_key. > > This will break the rdma-core userspace as well, with a similar > error: > > /usr/bin/clang-13 -DVERBS_DEBUG -Dibverbs_EXPORTS -Iinclude -I/usr/include/libnl3 -I/usr/include/drm -g -O2 -fdebug-prefix-map=/__w/1/s=. -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -Wmissing-prototypes -Wmissing-declarations -Wwrite-strings -Wformat=2 -Wcast-function-type -Wformat-nonliteral -Wdate-time -Wnested-externs -Wshadow -Wstrict-prototypes -Wold-style-definition -Werror -Wredundant-decls -g -fPIC -std=gnu11 -MD -MT libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -MF libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o.d -o libibverbs/CMakeFiles/ibverbs.dir/cmd_flow.c.o -c ../libibverbs/cmd_flow.c > In file included from ../libibverbs/cmd_flow.c:33: > In file included from include/infiniband/cmd_write.h:36: > In file included from include/infiniband/cmd_ioctl.h:41: > In file included from include/infiniband/verbs.h:48: > In file included from include/infiniband/verbs_api.h:66: > In file included from include/infiniband/ib_user_ioctl_verbs.h:38: > include/rdma/ib_user_verbs.h:436:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_cq_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_cq_resp base; > ^ > include/rdma/ib_user_verbs.h:644:34: error: field 'base' with variable sized type 'struct ib_uverbs_create_qp_resp' not at the end of a struct or class is a GNU extension [-Werror,-Wgnu-variable-sized-type-not-at-end] > struct ib_uverbs_create_qp_resp base; This looks very similar, a struct of unknown size is being treated as a header struct: struct ib_uverbs_create_cq_resp { __u32 cq_handle; __u32 cqe; __aligned_u64 driver_data[0]; }; struct ib_uverbs_ex_create_cq_resp { struct ib_uverbs_create_cq_resp base; __u32 comp_mask; __u32 response_length; }; And it only gets used here: DECLARE_UVERBS_WRITE(IB_USER_VERBS_CMD_CREATE_CQ, ib_uverbs_create_cq, UAPI_DEF_WRITE_UDATA_IO( struct ib_uverbs_create_cq, struct ib_uverbs_create_cq_resp), ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ UAPI_DEF_METHOD_NEEDS_FN(create_cq)), which must also be assuming it's a header. So probably better to just drop the driver_data field? I don't see anything using it (that I can find) besides as a sanity-check that the field exists and is at the end of the struct. -- Kees Cook