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 8098AC5479D for ; Fri, 6 Jan 2023 15:54:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232530AbjAFPyO (ORCPT ); Fri, 6 Jan 2023 10:54:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57638 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232981AbjAFPyK (ORCPT ); Fri, 6 Jan 2023 10:54:10 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8CA208CD09; Fri, 6 Jan 2023 07:54:07 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 2BAE2616FF; Fri, 6 Jan 2023 15:54:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E0429C433D2; Fri, 6 Jan 2023 15:54:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1673020446; bh=7cB3UhToZf19WjldWyLHUYEnxMRKMO5WZVXBb1fRwRs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j6p/ExogshxrCRekX6bJ3dnNQu8ehUl5v4Oq9PpfZ4QtduzTqmG+cCqr6f1z+7UOc HIbzWhBKwV2Vv5Fqz61ALO8qm6TGYpMMFx3AdlRn6oep788mro5a5/YpgDOlp3WBqR ZlRl1pMSZN6GczeFPeG/F3cVklimuLNMX4dSEYSAW5S5zUplTySkHUTypjgDUPtezu yfBoqAyEq3EUebZSRPlsI8bo2Bgg/850woK49aNhmPzliUmF+NoRmwr/HWMaRrCo5O yKEJkaEPke71vnT4AvI9NX/0aD607X5yEkLbPJUrEo1ROPZ6N8wg4UZYlkVClYMSIQ ZhGwLTrSSDeBg== Date: Fri, 6 Jan 2023 09:54:11 -0600 From: "Gustavo A. R. Silva" To: Kees Cook Cc: Helge Deller , linux-fbdev@vger.kernel.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: Re: [PATCH] fbdev: Replace 0-length array with flexible array Message-ID: References: <20230105192034.never.249-kees@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230105192034.never.249-kees@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-fbdev@vger.kernel.org On Thu, Jan 05, 2023 at 11:20:38AM -0800, Kees Cook wrote: > Zero-length arrays are deprecated[1]. Replace struct aperture's "ranges" > 0-length array with a flexible array. (How is the size of this array > verified?) Detected with GCC 13, using -fstrict-flex-arrays=3: > > samples/vfio-mdev/mdpy-fb.c: In function 'mdpy_fb_probe': > samples/vfio-mdev/mdpy-fb.c:169:32: warning: array subscript 0 is outside array bounds of 'struct aperture[0]' [-Warray-bounds=] > 169 | info->apertures->ranges[0].base = info->fix.smem_start; > | ~~~~~~~~~~~~~~~~~~~~~~~^~~ > In file included from samples/vfio-mdev/mdpy-fb.c:21: > include/linux/fb.h:510:19: note: while referencing 'ranges' > 510 | } ranges[0]; > | ^~~~~~ > > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays > > Cc: Helge Deller > Cc: "Gustavo A. R. Silva" > Cc: linux-fbdev@vger.kernel.org > Cc: dri-devel@lists.freedesktop.org > Signed-off-by: Kees Cook Reviewed-by: Gustavo A. R. Silva Thanks! -- Gustavo > --- > include/linux/fb.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/fb.h b/include/linux/fb.h > index 96b96323e9cb..bf59d6a3590f 100644 > --- a/include/linux/fb.h > +++ b/include/linux/fb.h > @@ -507,7 +507,7 @@ struct fb_info { > struct aperture { > resource_size_t base; > resource_size_t size; > - } ranges[0]; > + } ranges[]; > } *apertures; > > bool skip_vt_switch; /* no VT switch on suspend/resume required */ > -- > 2.34.1 >