From patchwork Tue Aug 30 20:13:51 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 9305969 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 E4256607F0 for ; Tue, 30 Aug 2016 20:14:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D54AE28D1E for ; Tue, 30 Aug 2016 20:14:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C9DD528D20; Tue, 30 Aug 2016 20:14:38 +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 40E9D28D1E for ; Tue, 30 Aug 2016 20:14:37 +0000 (UTC) Received: from localhost ([::1]:51056 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bepQa-0004Dx-4l for patchwork-qemu-devel@patchwork.kernel.org; Tue, 30 Aug 2016 16:14:36 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38088) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bepQ5-00044U-BC for qemu-devel@nongnu.org; Tue, 30 Aug 2016 16:14:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bepPz-0003RZ-CZ for qemu-devel@nongnu.org; Tue, 30 Aug 2016 16:14:04 -0400 Received: from mx1.redhat.com ([209.132.183.28]:37282) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bepPz-0003RE-7l for qemu-devel@nongnu.org; Tue, 30 Aug 2016 16:13:59 -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 206D381F07; Tue, 30 Aug 2016 20:13:58 +0000 (UTC) Received: from javelin.localdomain (vpn1-5-154.ams2.redhat.com [10.36.5.154]) by int-mx14.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u7UKDrUJ016463 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 30 Aug 2016 16:13:55 -0400 From: P J P To: Qemu Developers Date: Wed, 31 Aug 2016 01:43:51 +0530 Message-Id: <1472588031-6179-1-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 [10.5.110.27]); Tue, 30 Aug 2016 20:13:58 +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: check page count while initialising descriptor rings 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 , Tom Victor , 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 emulation uses command descriptors to process SCSI commands. These descriptors come with their ring buffers. A guest could set the page count for these rings to be zero, leading to an infinite loop. Add check to avoid it. Reported-by: Tom Victor Signed-off-by: Prasad J Pandit --- hw/scsi/vmw_pvscsi.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c index 5116f4a..68c1a00 100644 --- a/hw/scsi/vmw_pvscsi.c +++ b/hw/scsi/vmw_pvscsi.c @@ -160,8 +160,10 @@ pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri) uint32_t req_ring_size, cmp_ring_size; m->rs_pa = ri->ringsStatePPN << VMW_PAGE_SHIFT; - if ((ri->reqRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES) - || (ri->cmpRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)) { + if (!ri->reqRingNumPages + || ri->reqRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES + || !ri->cmpRingNumPages + || ri->cmpRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES) { return -1; } req_ring_size = ri->reqRingNumPages * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;