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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 0943CC77B7F for ; Fri, 18 Aug 2023 14:56:19 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qX0sh-0000ay-D7; Fri, 18 Aug 2023 10:55:19 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qX0sc-0000aJ-TM for qemu-devel@nongnu.org; Fri, 18 Aug 2023 10:55:14 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qX0sZ-0002lW-81 for qemu-devel@nongnu.org; Fri, 18 Aug 2023 10:55:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1692370509; h=from:from: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; bh=vEX9B0mVFIQUqp4+cCLBy4b68JxnxKcuqxCXBtpJ5tY=; b=QY66udU3mxIzW/61/iiONYP2y+3/NAshEoRW2k/RrBtX0UC8itW35KZYO+dr2Fq4jyUKGV WiPPFo726AiMAIAiy8ZAsi1xg1dUcI52du+kn2/GJL/yzBySQP+qHBDvnjzIAqpmXMxkQ5 khl6Wdeo132ewS5Y2g422G4T2SvYdJQ= 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-394-Gtaout8KPvqJcjJ3Gk5xdg-1; Fri, 18 Aug 2023 10:55:07 -0400 X-MC-Unique: Gtaout8KPvqJcjJ3Gk5xdg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 2BCBE85CBE0; Fri, 18 Aug 2023 14:55:07 +0000 (UTC) Received: from redhat.com (unknown [10.39.192.160]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 58F85621B7; Fri, 18 Aug 2023 14:55:06 +0000 (UTC) Date: Fri, 18 Aug 2023 16:55:05 +0200 From: Kevin Wolf To: Peter Maydell Cc: qemu-devel@nongnu.org, Philippe =?iso-8859-1?Q?Mathieu-Daud=E9?= , Hanna Reitz , qemu-block@nongnu.org Subject: Re: [PATCH] block/vpc: Avoid dynamic stack allocation Message-ID: References: <20230811175229.808139-1-peter.maydell@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230811175229.808139-1-peter.maydell@linaro.org> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.5 Received-SPF: pass client-ip=170.10.133.124; envelope-from=kwolf@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Am 11.08.2023 um 19:52 hat Peter Maydell geschrieben: > From: Philippe Mathieu-Daudé > > Use autofree heap allocation instead of variable-length array on the > stack. Here we don't expect the bitmap size to be enormous, and > since we're about to read/write it to disk the overhead of the > allocation should be fine. > > The codebase has very few VLAs, and if we can get rid of them all we > can make the compiler error on new additions. This is a defensive > measure against security bugs where an on-stack dynamic allocation > isn't correctly size-checked (e.g. CVE-2021-3527). > > Signed-off-by: Philippe Mathieu-Daudé > [PMM: expanded commit message] > Signed-off-by: Peter Maydell Thanks, applied to the block branch. Kevin