From patchwork Thu Oct 15 07:59:57 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Matteo Cascella X-Patchwork-Id: 1382489 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=PxJPln7I; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4CBhb938kDz9sT6 for ; Thu, 15 Oct 2020 19:02:29 +1100 (AEDT) Received: from localhost ([::1]:55516 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kSyDT-0005aD-Eg for incoming@patchwork.ozlabs.org; Thu, 15 Oct 2020 04:02:27 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:43864) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kSyBn-0005VW-Jd for qemu-devel@nongnu.org; Thu, 15 Oct 2020 04:00:43 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:24417) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kSyBk-0003G1-F9 for qemu-devel@nongnu.org; Thu, 15 Oct 2020 04:00:43 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602748839; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=nzZoV21xGCaBHRJLgLm4C8B75TwqLeTYx5aO+rkq//s=; b=PxJPln7IiyYoC/Bptw3hKS/Phlqyj4RwVptjkNg+upR1nk1h77O5A/f8xWkaZFl7rUPfpy VsiCTqAs0FjP1TUWBwnFxjZBV0XlfxGrrhV+agWf5vEok2FET1iE12MVcWJAvXsd7v6SPp 4d8lGwRHyX+KTKyQ/IBVkkdm3oa5pG8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-500-d-7153-jPKunAR-daNglXw-1; Thu, 15 Oct 2020 04:00:36 -0400 X-MC-Unique: d-7153-jPKunAR-daNglXw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EBE3918C89D0; Thu, 15 Oct 2020 08:00:34 +0000 (UTC) Received: from f32-work.redhat.com (unknown [10.40.194.72]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 8A4BA10013D7; Thu, 15 Oct 2020 08:00:27 +0000 (UTC) From: Mauro Matteo Cascella To: qemu-devel@nongnu.org Subject: [PATCH v2] hw/usb/hcd-dwc2: fix divide-by-zero in dwc2_handle_packet() Date: Thu, 15 Oct 2020 09:59:57 +0200 Message-Id: <20201015075957.268823-1-mcascell@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mcascell@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=63.128.21.124; envelope-from=mcascell@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/10/15 02:10:02 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H5=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: gaoning.pgn@antgroup.com, mcascell@redhat.com, linyi.lxw@antfin.com, kraxel@redhat.com, pauldzim@gmail.com Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" Check the value of mps to avoid potential divide-by-zero later in the function. Since HCCHAR_MPS is guest controllable, this prevents a malicious/buggy guest from crashing the QEMU process on the host. Signed-off-by: Mauro Matteo Cascella Reviewed-by: Paul Zimmerman Reported-by: Gaoning Pan Reported-by: Xingwei Lin Tested-by: Paul Zimmerman --- Moved check earlier in the function and added "Reviewed-by" line. hw/usb/hcd-dwc2.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/usb/hcd-dwc2.c b/hw/usb/hcd-dwc2.c index 97688d21bf..9856c4540c 100644 --- a/hw/usb/hcd-dwc2.c +++ b/hw/usb/hcd-dwc2.c @@ -245,6 +245,12 @@ static void dwc2_handle_packet(DWC2State *s, uint32_t devadr, USBDevice *dev, trace_usb_dwc2_handle_packet(chan, dev, &p->packet, epnum, types[eptype], dirs[epdir], mps, len, pcnt); + if (mps == 0) { + qemu_log_mask(LOG_GUEST_ERROR, + "%s: Bad HCCHAR_MPS set to zero\n", __func__); + return; + } + if (eptype == USB_ENDPOINT_XFER_CONTROL && pid == TSIZ_SC_MC_PID_SETUP) { pid = USB_TOKEN_SETUP; } else {