From patchwork Wed Sep 7 04:43:28 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 9318181 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6FFC56077F for ; Wed, 7 Sep 2016 04:44:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5A3842900C for ; Wed, 7 Sep 2016 04:44:36 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4F1BB2900E; Wed, 7 Sep 2016 04:44:36 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id CC7FF2900C for ; Wed, 7 Sep 2016 04:44:34 +0000 (UTC) Received: from localhost ([::1]:37866 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bhUiw-0000DY-3V for patchwork-qemu-devel@patchwork.kernel.org; Wed, 07 Sep 2016 00:44:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:32844) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bhUi9-0008MX-0U for qemu-devel@nongnu.org; Wed, 07 Sep 2016 00:43:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bhUi3-0002Ge-MA for qemu-devel@nongnu.org; Wed, 07 Sep 2016 00:43:43 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49242) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bhUi3-0002GD-GJ for qemu-devel@nongnu.org; Wed, 07 Sep 2016 00:43:39 -0400 Received: from int-mx14.intmail.prod.int.phx2.redhat.com (int-mx14.intmail.prod.int.phx2.redhat.com [10.5.11.27]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id D22778C55A; Wed, 7 Sep 2016 04:43:35 +0000 (UTC) Received: from javelin.localdomain (vpn1-7-86.ams2.redhat.com [10.36.7.86]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u874hTr4012079 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 7 Sep 2016 00:43:31 -0400 From: P J P To: Qemu Developers Date: Wed, 7 Sep 2016 10:13:28 +0530 Message-Id: <1473223408-24079-1-git-send-email-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.27 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Wed, 07 Sep 2016 04:43:38 +0000 (UTC) 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: pvscsi: limit process IO loop to maximum page count 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: Dmitry Fleytman , Paolo Bonzini , Li Qiang , Prasad J Pandit Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: Prasad J Pandit Vmware Paravirtual SCSI emulator while processing IO requests could run into an infinite loop if 'pvscsi_ring_pop_req_descr' always returned positive value. Limit IO loop to the maximum page count. Reported-by: Li Qiang Signed-off-by: Prasad J Pandit --- hw/scsi/vmw_pvscsi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c index babac5a..3e77a08 100644 --- a/hw/scsi/vmw_pvscsi.c +++ b/hw/scsi/vmw_pvscsi.c @@ -711,11 +711,13 @@ pvscsi_process_request_descriptor(PVSCSIState *s, static void pvscsi_process_io(PVSCSIState *s) { + int descr_pa_cnt = 0; PVSCSIRingReqDesc descr; hwaddr next_descr_pa; assert(s->rings_info_valid); - while ((next_descr_pa = pvscsi_ring_pop_req_descr(&s->rings)) != 0) { + while (((next_descr_pa = pvscsi_ring_pop_req_descr(&s->rings)) != 0) + && descr_pa_cnt++ < PVSCSI_SETUP_RINGS_MAX_NUM_PAGES) { /* Only read after production index verification */ smp_rmb();