From patchwork Thu Dec 17 16:19:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Markus Armbruster X-Patchwork-Id: 1417766 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=WCdgNMWT; dkim-atps=neutral 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 ozlabs.org (Postfix) with ESMTPS id 4CxcgH0H4kz9sWH for ; Fri, 18 Dec 2020 03:20:59 +1100 (AEDT) Received: from localhost ([::1]:46228 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kpw1Q-0002Dm-Uf for incoming@patchwork.ozlabs.org; Thu, 17 Dec 2020 11:20:56 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52806) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kpw0g-0002D2-6r for qemu-devel@nongnu.org; Thu, 17 Dec 2020 11:20:10 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:38626) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kpw0e-0005Nw-6O for qemu-devel@nongnu.org; Thu, 17 Dec 2020 11:20:09 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608222007; 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=z1gF9HfQAcfFrilbjpPxEtnwx7XSf+MCSBT33RJVHaU=; b=WCdgNMWTAdz3iMdEGeHxYDIZVVMJtWZRUt7TYVyMbfYh4xxZcA9w9oiKcPSI7y1k8YKtvQ ywPw4Z5BlErMrjdKiY5dyKdb4vjytcw2YwU/K/K+jCsBjdA9amp/sLshf0kNyPLqpWca3I KrB04EBCEQIx3UudTzgdjm8eeDFYpzE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-409-XP4cOm-zPVuIv5YE6zArYw-1; Thu, 17 Dec 2020 11:20:06 -0500 X-MC-Unique: XP4cOm-zPVuIv5YE6zArYw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0B9BAB8100; Thu, 17 Dec 2020 16:20:05 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-112-103.ams2.redhat.com [10.36.112.103]) by smtp.corp.redhat.com (Postfix) with ESMTPS id CF6D460CE7; Thu, 17 Dec 2020 16:20:04 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 638AD1141D30; Thu, 17 Dec 2020 17:20:03 +0100 (CET) From: Markus Armbruster To: qemu-devel@nongnu.org Subject: [PATCH 1/9] block/vpc: Make vpc_open() read the full dynamic header Date: Thu, 17 Dec 2020 17:19:55 +0100 Message-Id: <20201217162003.1102738-2-armbru@redhat.com> In-Reply-To: <20201217162003.1102738-1-armbru@redhat.com> References: <20201217162003.1102738-1-armbru@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=216.205.24.124; envelope-from=armbru@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_H3=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: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, mrezanin@redhat.com, qemu-block@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" The dynamic header's size is 1024 bytes. vpc_open() reads only the 512 bytes of the dynamic header into buf[]. Works, because it doesn't actually access the second half. However, a colleague told me that GCC 11 warns: ../block/vpc.c:358:51: error: array subscript 'struct VHDDynDiskHeader[0]' is partly outside array bounds of 'uint8_t[512]' [-Werror=array-bounds] Clean up to read the full header. Rename buf[] to dyndisk_header_buf[] while there. Signed-off-by: Markus Armbruster Reviewed-by: Max Reitz --- block/vpc.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/block/vpc.c b/block/vpc.c index 1ab55f9287..2fcf3f6283 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -220,7 +220,7 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, QemuOpts *opts = NULL; Error *local_err = NULL; bool use_chs; - uint8_t buf[HEADER_SIZE]; + uint8_t dyndisk_header_buf[1024]; uint32_t checksum; uint64_t computed_size; uint64_t pagetable_size; @@ -340,14 +340,14 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, } if (disk_type == VHD_DYNAMIC) { - ret = bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf, - HEADER_SIZE); + ret = bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), + dyndisk_header_buf, 1024); if (ret < 0) { error_setg(errp, "Error reading dynamic VHD header"); goto fail; } - dyndisk_header = (VHDDynDiskHeader *) buf; + dyndisk_header = (VHDDynDiskHeader *)dyndisk_header_buf; if (strncmp(dyndisk_header->magic, "cxsparse", 8)) { error_setg(errp, "Invalid header magic");