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 47FE5CDB482 for ; Sun, 15 Oct 2023 02:30:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233397AbjJOCaD (ORCPT ); Sat, 14 Oct 2023 22:30:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233328AbjJOCaB (ORCPT ); Sat, 14 Oct 2023 22:30:01 -0400 Received: from mail-pf1-x435.google.com (mail-pf1-x435.google.com [IPv6:2607:f8b0:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36DC8D8 for ; Sat, 14 Oct 2023 19:29:59 -0700 (PDT) Received: by mail-pf1-x435.google.com with SMTP id d2e1a72fcca58-6bd73395bceso168490b3a.0 for ; Sat, 14 Oct 2023 19:29:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1697336998; x=1697941798; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=dhN/OgC882rYGvnQvvtSIJopNEt0MUImMTuzjqZB2Xk=; b=Odi8MenDvKuf/AZcwNneuZFISXmSP4H8U2QnTOs9+tLcXMyrQNLcEq5oM1t0ELa5XI DPAWGPpjkHyon7/JTTZAgPY/HteOJpRDWphxmeF4BOphMAHqnt7RZBDW6IVJZGIoGDLr NPKv1l4UeDBU8qczVFi6AZfXG/jzFv++t1ilc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1697336998; x=1697941798; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=dhN/OgC882rYGvnQvvtSIJopNEt0MUImMTuzjqZB2Xk=; b=p7U+SGEt1KaK2+XZ5PhmnhAp6zXOQVH2JakNdmvIPgnRZU6VuZFJwieh3qk/vm2kwK hrqa8l/cTltLzl018faoA78/UgAm5OedYrMaP1nRXtH/yvv5XAwhg9LOm2muKt/tk87y fwzwR8NcsOEEQkN2D16Wan6OQ/dLVHZEMcBsiZmiKj4SBy2enWFYj/EaIC+Y8NI5xq/r BX42pIvXweyDcs1F7MOcCY2fbPVaOIkBqadF+0YYmNP0g26Fpx+rl/0l5sKqZVjrSeEH xsltG8WBIhNFxFw5kQRqb/G8+6T0nySta3UwbjyLF8Y5lNb3zPCQ5KIIiJdp79BGpkcR TkMw== X-Gm-Message-State: AOJu0YyV0wt2K3H0xCAUBzJpiHUIxNjGNf0DQbVMB9M/ck4wDQ1kPIAL SybDiH4OFUwHZvhMUkzfcXqtig== X-Google-Smtp-Source: AGHT+IHFveeRvUhPLEvQmB6YP6tVaXJOJXks9U+vR3El7JIrG5IcRyQop3DrOWjlCqDIVoZMvrQUcA== X-Received: by 2002:a05:6a00:318c:b0:68f:cdb8:ae33 with SMTP id bj12-20020a056a00318c00b0068fcdb8ae33mr5233919pfb.10.1697336998549; Sat, 14 Oct 2023 19:29:58 -0700 (PDT) Received: from www.outflux.net (198-0-35-241-static.hfc.comcastbusiness.net. [198.0.35.241]) by smtp.gmail.com with ESMTPSA id t1-20020a63b701000000b005776446f7cbsm4589302pgf.66.2023.10.14.19.29.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 14 Oct 2023 19:29:57 -0700 (PDT) Date: Sat, 14 Oct 2023 19:29:57 -0700 From: Kees Cook To: Christophe JAILLET Cc: Pravin B Shelar , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Gustavo A. R. Silva" , Nathan Chancellor , Nick Desaulniers , Tom Rix , linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, netdev@vger.kernel.org, dev@openvswitch.org, linux-hardening@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH v2 2/2] net: openvswitch: Annotate struct mask_array with __counted_by Message-ID: <202310141928.23985F1CA@keescook> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 14, 2023 at 08:34:53AM +0200, Christophe JAILLET wrote: > Prepare for the coming implementation by GCC and Clang of the __counted_by > attribute. Flexible array members annotated with __counted_by can have > their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS > (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family > functions). > > Signed-off-by: Christophe JAILLET > --- > v2: Fix the subject [Ilya Maximets] > fix the field name used with __counted_by [Ilya Maximets] > > v1: https://lore.kernel.org/all/f66ddcf1ef9328f10292ea75a17b584359b6cde3.1696156198.git.christophe.jaillet@wanadoo.fr/ > > > This patch is part of a work done in parallel of what is currently worked > on by Kees Cook. > > My patches are only related to corner cases that do NOT match the > semantic of his Coccinelle script[1]. > > In this case, in tbl_mask_array_alloc(), several things are allocated with > a single allocation. Then, some pointer arithmetic computes the address of > the memory after the flex-array. > > [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci > --- > net/openvswitch/flow_table.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/openvswitch/flow_table.h b/net/openvswitch/flow_table.h > index 9e659db78c05..f524dc3e4862 100644 > --- a/net/openvswitch/flow_table.h > +++ b/net/openvswitch/flow_table.h > @@ -48,7 +48,7 @@ struct mask_array { > int count, max; > struct mask_array_stats __percpu *masks_usage_stats; > u64 *masks_usage_zero_cntr; > - struct sw_flow_mask __rcu *masks[]; > + struct sw_flow_mask __rcu *masks[] __counted_by(max); > }; Yup, this looks correct to me. Thanks! Reviewed-by: Kees Cook -- Kees Cook