From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f179.google.com (mail-pf1-f179.google.com [209.85.210.179]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 66FAE111F for ; Sun, 15 Oct 2023 02:29:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="lAiHymfE" Received: by mail-pf1-f179.google.com with SMTP id d2e1a72fcca58-6bd73395bceso168493b3a.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=lists.linux.dev; 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=lAiHymfE3A8+eE7uNFMCyMxwceDW7dDfyLIBMY4lpqisp58J3tsNwoxWZlO4u3h/4G S1dwjSMQ4hvPOpDC7vAPNA8Cl04JTzn7aWm2TVH/jL3SJ3Ck7yg2frgsU4LJyrL1QtBJ 7LRH2OOBZY2oXbfzurppMPGoY3sOy4giD1ZEg= 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=NOF+EAKdM48eCSv+wnFLwg5Vso+DSqw3mjEhsleolCBRk3aQbogS180eqZGjBPJIMJ Gnk7xqcjGnyLyYMDs5DT+AZaXqed1mtOGA5AiKNYMT1hStDw6GgI3GesJ8WG5FWb1WHl MakRMPb+7I6glrS/Slpor5MblYZqZuZ4N/dpP4Qe+ZGh7vO7YzqhT1WVKYhKQ6e2Bj65 /Mh2jGNopCIbNZBTuj4qIrRfikyzvH/ob6Ltt/PFbD07UBIrQTnuIaxhvXcJVuSEnT// HJwX7F4dE8CVNObOU02zl5ibqiZxr/+pNR0ZbeXiZU1yoWSbwZOe9pvhxnNBWtUSuK7n CwOA== X-Gm-Message-State: AOJu0YwBRKxa4uSN596Z2l+QeSAdsXSlWIuOocTPk5Nxwg8sN+c5F2vP V1iiP8ur1kcSdHYNRLSy3Hga9A== 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: Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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