From patchwork Mon May 23 10:48:05 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Prasad Pandit X-Patchwork-Id: 9131445 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 26D9F60761 for ; Mon, 23 May 2016 10:48:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 16E552822F for ; Mon, 23 May 2016 10:48:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0BD3028233; Mon, 23 May 2016 10:48:45 +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 5E00428231 for ; Mon, 23 May 2016 10:48:44 +0000 (UTC) Received: from localhost ([::1]:46738 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b4nPe-0000ZN-EL for patchwork-qemu-devel@patchwork.kernel.org; Mon, 23 May 2016 06:48:42 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54797) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b4nPO-0000Z5-EI for qemu-devel@nongnu.org; Mon, 23 May 2016 06:48:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b4nPK-0007Xd-FM for qemu-devel@nongnu.org; Mon, 23 May 2016 06:48:26 -0400 Received: from mx1.redhat.com ([209.132.183.28]:35584) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b4nPK-0007XS-77 for qemu-devel@nongnu.org; Mon, 23 May 2016 06:48:22 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (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 D282E6265C; Mon, 23 May 2016 10:48:19 +0000 (UTC) Received: from javelin.localdomain (vpn1-48-118.bne.redhat.com [10.64.48.118]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u4NAm891018163 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 23 May 2016 06:48:12 -0400 From: P J P To: Qemu Developers Date: Mon, 23 May 2016 16:18:05 +0530 Message-Id: <1464000485-27041-1-git-send-email-ppandit@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Mon, 23 May 2016 10:48:20 +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: check command descriptor ring buffer 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 , Prasad J Pandit , Idan Brown , Dmitry Fleytman , Paolo Bonzini , Shmulik Ladkani 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 ring buffer size to an arbitrary value leading to OOB access issue. Add check to avoid it. Reported-by: Li Qiang Signed-off-by: Prasad J Pandit Reviewed-by: Shmulik Ladkani Reviewed-by: Dmitry Fleytman --- hw/scsi/vmw_pvscsi.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c index e690b4e..e1d6d06 100644 --- a/hw/scsi/vmw_pvscsi.c +++ b/hw/scsi/vmw_pvscsi.c @@ -153,7 +153,7 @@ pvscsi_log2(uint32_t input) return log; } -static void +static int pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri) { int i; @@ -161,6 +161,10 @@ 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)) { + return -1; + } req_ring_size = ri->reqRingNumPages * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE; cmp_ring_size = ri->cmpRingNumPages * PVSCSI_MAX_NUM_CMP_ENTRIES_PER_PAGE; txr_len_log2 = pvscsi_log2(req_ring_size - 1); @@ -192,15 +196,20 @@ pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri) /* Flush ring state page changes */ smp_wmb(); + + return 0; } -static void +static int pvscsi_ring_init_msg(PVSCSIRingInfo *m, PVSCSICmdDescSetupMsgRing *ri) { int i; uint32_t len_log2; uint32_t ring_size; + if (ri->numPages > PVSCSI_SETUP_MSG_RING_MAX_NUM_PAGES) { + return -1; + } ring_size = ri->numPages * PVSCSI_MAX_NUM_MSG_ENTRIES_PER_PAGE; len_log2 = pvscsi_log2(ring_size - 1); @@ -220,6 +229,8 @@ pvscsi_ring_init_msg(PVSCSIRingInfo *m, PVSCSICmdDescSetupMsgRing *ri) /* Flush ring state page changes */ smp_wmb(); + + return 0; } static void @@ -770,7 +781,10 @@ pvscsi_on_cmd_setup_rings(PVSCSIState *s) trace_pvscsi_on_cmd_arrived("PVSCSI_CMD_SETUP_RINGS"); pvscsi_dbg_dump_tx_rings_config(rc); - pvscsi_ring_init_data(&s->rings, rc); + if (pvscsi_ring_init_data(&s->rings, rc) < 0) { + return PVSCSI_COMMAND_PROCESSING_FAILED; + } + s->rings_info_valid = TRUE; return PVSCSI_COMMAND_PROCESSING_SUCCEEDED; } @@ -850,7 +864,9 @@ pvscsi_on_cmd_setup_msg_ring(PVSCSIState *s) } if (s->rings_info_valid) { - pvscsi_ring_init_msg(&s->rings, rc); + if (pvscsi_ring_init_msg(&s->rings, rc) < 0) { + return PVSCSI_COMMAND_PROCESSING_FAILED; + } s->msg_ring_info_valid = TRUE; } return sizeof(PVSCSICmdDescSetupMsgRing) / sizeof(uint32_t);