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 X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,URIBL_SBL,URIBL_SBL_A autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6677FC0650F for ; Thu, 8 Aug 2019 06:36:29 +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 3A7CD217F4 for ; Thu, 8 Aug 2019 06:36:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3A7CD217F4 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+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:47184 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvc2G-0005AD-G7 for qemu-devel@archiver.kernel.org; Thu, 08 Aug 2019 02:36:28 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:45626) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hvc1b-0004P4-TZ for qemu-devel@nongnu.org; Thu, 08 Aug 2019 02:35:48 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hvc1a-0003tU-Qx for qemu-devel@nongnu.org; Thu, 08 Aug 2019 02:35:47 -0400 Received: from mx1.redhat.com ([209.132.183.28]:45516) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1hvc1a-0003pj-LK for qemu-devel@nongnu.org; Thu, 08 Aug 2019 02:35:46 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 554AB30FB8C8; Thu, 8 Aug 2019 06:35:45 +0000 (UTC) Received: from localhost.localdomain (unknown [10.65.150.157]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 189155D9DC; Thu, 8 Aug 2019 06:35:42 +0000 (UTC) From: P J P To: QEMU Developers Date: Thu, 8 Aug 2019 12:03:40 +0530 Message-Id: <20190808063340.23833-1-ppandit@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Thu, 08 Aug 2019 06:35:45 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH] scsi: lsi: exit infinite loop while executing script (CVE-2019-12068) 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: Fam Zheng , Paolo Bonzini , Bugs SysSec , Prasad J Pandit Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Prasad J Pandit When executing script in lsi_execute_script(), the LSI scsi adapter emulator advances 's->dsp' index to read next opcode. This can lead to an infinite loop if the next opcode is empty. Exit such loop after reading 10k empty opcodes. Reported-by: Bugs SysSec Signed-off-by: Prasad J Pandit --- hw/scsi/lsi53c895a.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c index 10468c1ec1..c23a40525e 100644 --- a/hw/scsi/lsi53c895a.c +++ b/hw/scsi/lsi53c895a.c @@ -1132,7 +1132,10 @@ static void lsi_execute_script(LSIState *s) =20 s->istat1 |=3D LSI_ISTAT1_SRUN; again: - insn_processed++; + if (++insn_processed > 10000) { + s->waiting =3D LSI_NOWAIT; + goto exitloop; + } insn =3D read_dword(s, s->dsp); if (!insn) { /* If we receive an empty opcode increment the DSP by 4 bytes @@ -1569,6 +1572,7 @@ again: } } } +exitloop: if (insn_processed > 10000 && s->waiting =3D=3D LSI_NOWAIT) { /* Some windows drivers make the device spin waiting for a memor= y location to change. If we have been executed a lot of code t= hen --=20 2.21.0