From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 974C53D99D; Tue, 17 Oct 2023 09:10:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HYFrKPux" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0C7A1C433C8; Tue, 17 Oct 2023 09:10:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697533809; bh=XzWNIY/hrbTa3IpvjUeTL3enp5iOsmUIH+SzZ2/j/S4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=HYFrKPuxxNnAO4bIJuWAo3vtIdUGAyUiM0Ji3FbzfmtycscCLf6EbhI0QBq1XyWZp v9HCOlY08mIS+7BDSJEyqQ9hbVrLXQ+qUeYPciXTcPP2mswDuUoDVITdjw8G3MYpm3 0yy0JpWRsLtBixnefQMKg8SBdh6hldh8rt4ltCZsuipjz11rIaPwSpRLR1s8KCcH7k 1oC4SuX7bcQk5aS6RpG41SLA0wEqXTzSFX2TndKUdUGP97V82uFSw+wpNHJV31PDeq vvMssJPuN3bgBsQsFyDvrPPlHo6QmDFEOuLMGFSH1jCL9zh28CM9ChnDRQIK8ffU4Q vioQ+2/eFWkcw== Date: Tue, 17 Oct 2023 11:10:02 +0200 From: Simon Horman To: Kees Cook Cc: Christophe JAILLET , dev@openvswitch.org, kernel-janitors@vger.kernel.org, Tom Rix , llvm@lists.linux.dev, Nick Desaulniers , "Gustavo A. R. Silva" , Nathan Chancellor , Eric Dumazet , linux-hardening@vger.kernel.org, netdev@vger.kernel.org, Jakub Kicinski , Paolo Abeni , "David S. Miller" , linux-kernel@vger.kernel.org Subject: Re: [ovs-dev] [PATCH v2 2/2] net: openvswitch: Annotate struct mask_array with __counted_by Message-ID: <20231017091002.GR1751252@kernel.org> References: <202310141928.23985F1CA@keescook> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <202310141928.23985F1CA@keescook> On Sat, Oct 14, 2023 at 07:29:57PM -0700, Kees Cook wrote: > 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 > Likewise, I agree this is correct. Reviewed-by: Simon Horman