From patchwork Wed Sep 23 10:41:01 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= X-Patchwork-Id: 11794795 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 18B83618 for ; Wed, 23 Sep 2020 10:44:26 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id BEF5721D7D for ; Wed, 23 Sep 2020 10:44:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cyxrZjgD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BEF5721D7D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:49572 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kL2G8-0002Z0-Nt for patchwork-qemu-devel@patchwork.kernel.org; Wed, 23 Sep 2020 06:44:24 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50830) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kL2DN-00085H-0r for qemu-devel@nongnu.org; Wed, 23 Sep 2020 06:41:33 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:34894) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kL2DI-0006xX-GU for qemu-devel@nongnu.org; Wed, 23 Sep 2020 06:41:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600857686; 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=Phgc4cmO3ruvrymUHH88m7f0AQy1BCw/bV6mMezeXhc=; b=cyxrZjgD0dH0HkM87q7eabdnAfHl84J4wpefdWoy8KCKzjgKbVq5CHkWcmADKGuVfvdn6b SLBOhwjRf8vh+O91J74hyG5KzAxO1JJlQCYgC23tF2oSqlQDPxaYq5ph/hDcbueV0o8Uvf Fqtrd1gxdHl9mqrqMLbr4EckIbelO/g= 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-324-4wht2beYNFGWIDv3DRZiRA-1; Wed, 23 Sep 2020 06:41:22 -0400 X-MC-Unique: 4wht2beYNFGWIDv3DRZiRA-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 7CAF9393B6; Wed, 23 Sep 2020 10:41:21 +0000 (UTC) Received: from localhost.localdomain.com (ovpn-114-73.ams2.redhat.com [10.36.114.73]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6D4021002C03; Wed, 23 Sep 2020 10:41:18 +0000 (UTC) From: =?utf-8?q?Daniel_P=2E_Berrang=C3=A9?= To: qemu-devel@nongnu.org Subject: [PATCH v2 2/3] hw/smbios: report error if table size is too large Date: Wed, 23 Sep 2020 11:41:01 +0100 Message-Id: <20200923104102.2068416-3-berrange@redhat.com> In-Reply-To: <20200923104102.2068416-1-berrange@redhat.com> References: <20200923104102.2068416-1-berrange@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=63.128.21.124; envelope-from=berrange@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/09/23 00:53:58 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -35 X-Spam_score: -3.6 X-Spam_bar: --- X-Spam_report: (-3.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1.455, 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_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable 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: Peter Maydell , =?utf-8?q?Daniel_P=2E_Berrang?= =?utf-8?q?=C3=A9?= , Eduardo Habkost , "Michael S. Tsirkin" , Markus Armbruster , =?utf-8?q?Philippe_Mathieu-Daud?= =?utf-8?q?=C3=A9?= , qemu-arm@nongnu.org, Paolo Bonzini , Igor Mammedov , Laszlo Ersek , Richard Henderson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" The SMBIOS 2.1 entry point uses a uint16 data type for reporting the total length of the tables. If the user passes -smbios configuration to QEMU that causes the table size to exceed this limit then various bad behaviours result, including - firmware hangs in an infinite loop - firmware triggers a KVM crash on bad memory access - firmware silently discards user's SMBIOS data replacing it with a generic data set. Limiting the size to 0xffff in QEMU avoids triggering most of these problems. There is a remaining bug in SeaBIOS which tries to prepend its own data for table 0, and does not check whether there is sufficient space before attempting this. Reviewed-by: Igor Mammedov Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Daniel P. Berrangé --- hw/smbios/smbios.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/hw/smbios/smbios.c b/hw/smbios/smbios.c index 8450fad285..3c87be6c91 100644 --- a/hw/smbios/smbios.c +++ b/hw/smbios/smbios.c @@ -365,6 +365,13 @@ static void smbios_register_config(void) opts_init(smbios_register_config); +/* + * The SMBIOS 2.1 "structure table length" field in the + * entry point uses a 16-bit integer, so we're limited + * in total table size + */ +#define SMBIOS_21_MAX_TABLES_LEN 0xffff + static void smbios_validate_table(MachineState *ms) { uint32_t expect_t4_count = smbios_legacy ? @@ -375,6 +382,13 @@ static void smbios_validate_table(MachineState *ms) expect_t4_count, smbios_type4_count); exit(1); } + + if (smbios_ep_type == SMBIOS_ENTRY_POINT_21 && + smbios_tables_len > SMBIOS_21_MAX_TABLES_LEN) { + error_report("SMBIOS 2.1 table length %zu exceeds %d", + smbios_tables_len, SMBIOS_21_MAX_TABLES_LEN); + exit(1); + } }