From nobody Sat Oct 25 08:52:39 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=redhat.com Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1520421890446542.234578080461; Wed, 7 Mar 2018 03:24:50 -0800 (PST) Received: from localhost ([::1]:60872 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1etXBg-000140-NW for importer@patchew.org; Wed, 07 Mar 2018 06:24:48 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:35941) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1etX5f-0004BR-V5 for qemu-devel@nongnu.org; Wed, 07 Mar 2018 06:18:37 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1etX5d-0005hC-Q0 for qemu-devel@nongnu.org; Wed, 07 Mar 2018 06:18:35 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:37112 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1etX5d-0005gx-Kr for qemu-devel@nongnu.org; Wed, 07 Mar 2018 06:18:33 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4D8B7D1424; Wed, 7 Mar 2018 11:18:33 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-116-216.ams2.redhat.com [10.36.116.216]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9573D215CDAA; Wed, 7 Mar 2018 11:18:32 +0000 (UTC) From: Kevin Wolf To: qemu-devel@nongnu.org Date: Wed, 7 Mar 2018 12:18:19 +0100 Message-Id: <20180307111822.29403-2-kwolf@redhat.com> In-Reply-To: <20180307111822.29403-1-kwolf@redhat.com> References: <20180307111822.29403-1-kwolf@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 07 Mar 2018 11:18:33 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Wed, 07 Mar 2018 11:18:33 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'kwolf@redhat.com' RCPT:'' X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 66.187.233.73 Subject: [Qemu-devel] [PULL 1/4] multiboot: bss_end_addr can be zero X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: kwolf@redhat.com, jack.schwartz@oracle.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Jack Schwartz The multiboot spec (https://www.gnu.org/software/grub/manual/multiboot/), section 3.1.3, allows for bss_end_addr to be zero. A zero bss_end_addr signifies there is no .bss section. Suggested-by: Daniel Kiper Signed-off-by: Jack Schwartz Reviewed-by: Daniel Kiper Reviewed-by: Prasad J Pandit Signed-off-by: Kevin Wolf --- hw/i386/multiboot.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/hw/i386/multiboot.c b/hw/i386/multiboot.c index 46d9c68bf5..bb8d8e4629 100644 --- a/hw/i386/multiboot.c +++ b/hw/i386/multiboot.c @@ -233,12 +233,6 @@ int load_multiboot(FWCfgState *fw_cfg, mh_entry_addr =3D ldl_p(header+i+28); =20 if (mh_load_end_addr) { - if (mh_bss_end_addr < mh_load_addr) { - fprintf(stderr, "invalid mh_bss_end_addr address\n"); - exit(1); - } - mb_kernel_size =3D mh_bss_end_addr - mh_load_addr; - if (mh_load_end_addr < mh_load_addr) { fprintf(stderr, "invalid mh_load_end_addr address\n"); exit(1); @@ -249,8 +243,16 @@ int load_multiboot(FWCfgState *fw_cfg, fprintf(stderr, "invalid kernel_file_size\n"); exit(1); } - mb_kernel_size =3D kernel_file_size - mb_kernel_text_offset; - mb_load_size =3D mb_kernel_size; + mb_load_size =3D kernel_file_size - mb_kernel_text_offset; + } + if (mh_bss_end_addr) { + if (mh_bss_end_addr < (mh_load_addr + mb_load_size)) { + fprintf(stderr, "invalid mh_bss_end_addr address\n"); + exit(1); + } + mb_kernel_size =3D mh_bss_end_addr - mh_load_addr; + } else { + mb_kernel_size =3D mb_load_size; } =20 /* Valid if mh_flags sets MULTIBOOT_HEADER_HAS_VBE. --=20 2.13.6