From patchwork Tue Nov 22 12:56:51 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 9441029 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 3D5E6600BA for ; Tue, 22 Nov 2016 12:59:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2E38028524 for ; Tue, 22 Nov 2016 12:59:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 22D8328528; Tue, 22 Nov 2016 12:59:10 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id A3FA728524 for ; Tue, 22 Nov 2016 12:59:09 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1c9AdA-0001KL-F7; Tue, 22 Nov 2016 12:57:00 +0000 Received: from mail6.bemta3.messagelabs.com ([195.245.230.39]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1c9Ad9-0001K8-Gd for xen-devel@lists.xenproject.org; Tue, 22 Nov 2016 12:56:59 +0000 Received: from [85.158.137.68] by server-12.bemta-3.messagelabs.com id CF/7D-28947-A9044385; Tue, 22 Nov 2016 12:56:58 +0000 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupmkeJIrShJLcpLzFFi42LpdPzhpTvLwST CYOJKHovvWyYzOTB6HP5whSWAMYo1My8pvyKBNeNQf3TBWoGKxbeaWRsYn3B3MXJyCAnkSczb /Zeti5GDg1fATuLrUhuQsISAocTT99fZQGwWAVWJN6susoPYbALqEm3PtrOC2CIC0hL9c9rB4 swCCRLXuz6AxYUFNCRWT33FCDFSUOLvDmGIEi2Jh79usUDY2hLLFr5mBilhBhqz/B/HBEaeWQ gNs5A0zELSMAuhYQEjyypGjeLUorLUIl1DI72kosz0jJLcxMwcXUMDY73c1OLixPTUnMSkYr3 k/NxNjMBAYgCCHYyvup0PMUpyMCmJ8h5eahQhxJeUn1KZkVicEV9UmpNafIhRhoNDSYI3y94k QkiwKDU9tSItMwcY0jBpCQ4eJRHeMyBp3uKCxNzizHSI1ClGRSlxXh+QhABIIqM0D64NFkeXG GWlhHkZgQ4R4ilILcrNLEGVf8UozsGoJMyrAjKFJzOvBG76K6DFTECLJb8ZgywuSURISTUwqs 7Q2+FzvWPT5LevJnNUBmSlSZXurT4ScfqD95ZPvZvrJ/gtapW6/3Ti2ZLnzO+ZlrIt3FE0J9E h7sla07cdUx3VfrnO8+FbqRFzIu5AQeMekZ8PDTjmbgvP2eEiskFo0iq1tlAPFY86fblTs1IS J79hPZ31ysPjhPaWVa8nM918nLHHgX22pxJLcUaioRZzUXEiAKg2fAmeAgAA X-Env-Sender: JBeulich@suse.com X-Msg-Ref: server-15.tower-31.messagelabs.com!1479819416!68266267!1 X-Originating-IP: [137.65.248.74] X-SpamReason: No, hits=0.0 required=7.0 tests= X-StarScan-Received: X-StarScan-Version: 9.0.16; banners=-,-,- X-VirusChecked: Checked Received: (qmail 9249 invoked from network); 22 Nov 2016 12:56:57 -0000 Received: from prv-mh.provo.novell.com (HELO prv-mh.provo.novell.com) (137.65.248.74) by server-15.tower-31.messagelabs.com with DHE-RSA-AES256-GCM-SHA384 encrypted SMTP; 22 Nov 2016 12:56:57 -0000 Received: from INET-PRV-MTA by prv-mh.provo.novell.com with Novell_GroupWise; Tue, 22 Nov 2016 05:56:55 -0700 Message-Id: <58344EA30200007800120C8A@prv-mh.provo.novell.com> X-Mailer: Novell GroupWise Internet Agent 14.2.1 Date: Tue, 22 Nov 2016 05:56:51 -0700 From: "Jan Beulich" To: Mime-Version: 1.0 Content-Disposition: inline Cc: xen-devel , Stefano Stabellini Subject: [Xen-devel] [PATCH] xen: fix ioreq handling X-BeenThere: xen-devel@lists.xen.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" X-Virus-Scanned: ClamAV using ClamSMTP Avoid double fetches and bounds check size to avoid overflowing internal variables. This is CVE-2016-9381 / XSA-197. Reported-by: yanghongke Signed-off-by: Jan Beulich Reviewed-by: Stefano Stabellini --- a/xen-hvm.c +++ b/xen-hvm.c @@ -810,6 +810,10 @@ static void cpu_ioreq_pio(ioreq_t *req) trace_cpu_ioreq_pio(req, req->dir, req->df, req->data_is_ptr, req->addr, req->data, req->count, req->size); + if (req->size > sizeof(uint32_t)) { + hw_error("PIO: bad size (%u)", req->size); + } + if (req->dir == IOREQ_READ) { if (!req->data_is_ptr) { req->data = do_inp(req->addr, req->size); @@ -846,6 +850,10 @@ static void cpu_ioreq_move(ioreq_t *req) trace_cpu_ioreq_move(req, req->dir, req->df, req->data_is_ptr, req->addr, req->data, req->count, req->size); + if (req->size > sizeof(req->data)) { + hw_error("MMIO: bad size (%u)", req->size); + } + if (!req->data_is_ptr) { if (req->dir == IOREQ_READ) { for (i = 0; i < req->count; i++) { @@ -1010,11 +1018,13 @@ static int handle_buffered_iopage(XenIOS req.df = 1; req.type = buf_req->type; req.data_is_ptr = 0; + xen_rmb(); qw = (req.size == 8); if (qw) { buf_req = &buf_page->buf_ioreq[(rdptr + 1) % IOREQ_BUFFER_SLOT_NUM]; req.data |= ((uint64_t)buf_req->data) << 32; + xen_rmb(); } handle_ioreq(state, &req); @@ -1045,7 +1055,11 @@ static void cpu_handle_ioreq(void *opaqu handle_buffered_iopage(state); if (req) { - handle_ioreq(state, req); + ioreq_t copy = *req; + + xen_rmb(); + handle_ioreq(state, ©); + req->data = copy.data; if (req->state != STATE_IOREQ_INPROCESS) { fprintf(stderr, "Badness in I/O request ... not in service?!: "