From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41752) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bWrk6-0003x9-1D for qemu-devel@nongnu.org; Mon, 08 Aug 2016 17:05:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bWrk2-0005uP-Pu for qemu-devel@nongnu.org; Mon, 08 Aug 2016 17:05:49 -0400 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:42205 helo=mx0a-001b2d01.pphosted.com) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bWrk2-0005uG-Kh for qemu-devel@nongnu.org; Mon, 08 Aug 2016 17:05:46 -0400 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.11/8.16.0.11) with SMTP id u78Kxlbm071807 for ; Mon, 8 Aug 2016 17:05:46 -0400 Received: from e37.co.us.ibm.com (e37.co.us.ibm.com [32.97.110.158]) by mx0b-001b2d01.pphosted.com with ESMTP id 24nc1q7v11-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Mon, 08 Aug 2016 17:05:46 -0400 Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 8 Aug 2016 15:05:45 -0600 From: Michael Roth Date: Mon, 8 Aug 2016 16:03:54 -0500 In-Reply-To: <1470690267-31454-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1470690267-31454-1-git-send-email-mdroth@linux.vnet.ibm.com> Message-Id: <1470690267-31454-24-git-send-email-mdroth@linux.vnet.ibm.com> Subject: [Qemu-devel] [PATCH 23/56] scsi: pvscsi: check command descriptor ring buffer size (CVE-2016-4952) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: qemu-stable@nongnu.org, Prasad J Pandit , Paolo Bonzini 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 Cc: qemu-stable@nongnu.org Message-Id: <1464000485-27041-1-git-send-email-ppandit@redhat.com> Reviewed-by: Shmulik Ladkani Reviewed-by: Dmitry Fleytman Signed-off-by: Paolo Bonzini (cherry picked from commit 3e831b40e015ba34dfb55ff11f767001839425ff) Signed-off-by: Michael Roth --- 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); -- 1.9.1