From patchwork Thu Mar 29 08:00:04 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Wang X-Patchwork-Id: 10314681 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 3362C60353 for ; Thu, 29 Mar 2018 08:00:40 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2AEB02A2C9 for ; Thu, 29 Mar 2018 08:00:40 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 29B332A2B0; Thu, 29 Mar 2018 08:00:40 +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=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5DCDB2A2C9 for ; Thu, 29 Mar 2018 08:00:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751106AbeC2IAN (ORCPT ); Thu, 29 Mar 2018 04:00:13 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:47610 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750707AbeC2IAM (ORCPT ); Thu, 29 Mar 2018 04:00:12 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 705C917A0C1; Thu, 29 Mar 2018 08:00:11 +0000 (UTC) Received: from jason-ThinkPad-T450s.redhat.com (ovpn-12-196.pek2.redhat.com [10.72.12.196]) by smtp.corp.redhat.com (Postfix) with ESMTP id E212F2024CA4; Thu, 29 Mar 2018 08:00:06 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net] vhost: validate log when IOTLB is enabled Date: Thu, 29 Mar 2018 16:00:04 +0800 Message-Id: <1522310404-8486-1-git-send-email-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Thu, 29 Mar 2018 08:00:11 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Thu, 29 Mar 2018 08:00:11 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'jasowang@redhat.com' RCPT:'' Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Vq log_base is the userspace address of bitmap which has nothing to do with IOTLB. So it needs to be validated unconditionally otherwise we may try use 0 as log_base which may lead to pin pages that will lead unexpected result (e.g trigger BUG_ON() in set_bit_to_user()). Fixes: 6b1e6cc7855b0 ("vhost: new device IOTLB API") Reported-by: syzbot+6304bf97ef436580fede@syzkaller.appspotmail.com Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin --- drivers/vhost/vhost.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 5d5a9d9..5320039 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1244,14 +1244,12 @@ static int vq_log_access_ok(struct vhost_virtqueue *vq, /* Caller should have vq mutex and device mutex */ int vhost_vq_access_ok(struct vhost_virtqueue *vq) { - if (vq->iotlb) { - /* When device IOTLB was used, the access validation - * will be validated during prefetching. - */ - return 1; - } - return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used) && - vq_log_access_ok(vq, vq->log_base); + int ret = vq_log_access_ok(vq, vq->log_base); + + if (ret || vq->iotlb) + return ret; + + return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used); } EXPORT_SYMBOL_GPL(vhost_vq_access_ok);