From patchwork Wed Sep 14 09:39:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 9331009 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 29D1260231 for ; Wed, 14 Sep 2016 09:45:57 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1A87029BFB for ; Wed, 14 Sep 2016 09:45:57 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0D23029C0E; Wed, 14 Sep 2016 09:45:57 +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 1D84129BFB for ; Wed, 14 Sep 2016 09:45:54 +0000 (UTC) Received: from localhost ([::1]:54706 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bk6lN-0001Vc-Uv for patchwork-qemu-devel@patchwork.kernel.org; Wed, 14 Sep 2016 05:45:53 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55131) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bk6f6-0005HL-6G for qemu-devel@nongnu.org; Wed, 14 Sep 2016 05:39:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bk6f1-0003oN-6S for qemu-devel@nongnu.org; Wed, 14 Sep 2016 05:39:23 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40608) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bk6f1-0003o9-17 for qemu-devel@nongnu.org; Wed, 14 Sep 2016 05:39:19 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (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 50F84B9AD9; Wed, 14 Sep 2016 09:39:18 +0000 (UTC) Received: from javelin.localdomain (vpn1-6-59.sin2.redhat.com [10.67.6.59]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u8E9dE1t014816 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 14 Sep 2016 05:39:16 -0400 From: P J P To: Dmitry Fleytman Date: Wed, 14 Sep 2016 15:09:12 +0530 Message-Id: <1473845952-30785-1-git-send-email-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.26 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Wed, 14 Sep 2016 09:39:18 +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 v2] scsi: pvscsi: limit process IO loop to ring size 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: Li Qiang , Qemu Developers , 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 ring size. Reported-by: Li Qiang Signed-off-by: Prasad J Pandit --- hw/scsi/vmw_pvscsi.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) Update per: -> https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg02711.html diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c index 4245c15..4d94b36 100644 --- a/hw/scsi/vmw_pvscsi.c +++ b/hw/scsi/vmw_pvscsi.c @@ -245,8 +245,11 @@ static hwaddr pvscsi_ring_pop_req_descr(PVSCSIRingInfo *mgr) { uint32_t ready_ptr = RS_GET_FIELD(mgr, reqProdIdx); + uint32_t ring_size = PVSCSI_MAX_NUM_PAGES_REQ_RING + * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE; - if (ready_ptr != mgr->consumed_ptr) { + if (ready_ptr != mgr->consumed_ptr + && ready_ptr - mgr->consumed_ptr < ring_size) { uint32_t next_ready_ptr = mgr->consumed_ptr++ & mgr->txr_len_mask; uint32_t next_ready_page =