From patchwork Mon Apr 9 19:40:02 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Michael S. Tsirkin" X-Patchwork-Id: 10331955 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 5B2036037F for ; Mon, 9 Apr 2018 19:40:21 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4C87828BF0 for ; Mon, 9 Apr 2018 19:40:21 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4145028BF4; Mon, 9 Apr 2018 19:40:21 +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=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, 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 C796F28BF0 for ; Mon, 9 Apr 2018 19:40:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754299AbeDITkG (ORCPT ); Mon, 9 Apr 2018 15:40:06 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:53756 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754136AbeDITkE (ORCPT ); Mon, 9 Apr 2018 15:40:04 -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 D92AD7D843; Mon, 9 Apr 2018 19:40:03 +0000 (UTC) Received: from redhat.com (ovpn-125-238.rdu2.redhat.com [10.10.125.238]) by smtp.corp.redhat.com (Postfix) with SMTP id 1FE5C2024CA7; Mon, 9 Apr 2018 19:40:02 +0000 (UTC) Date: Mon, 9 Apr 2018 22:40:02 +0300 From: "Michael S. Tsirkin" To: David Miller , netdev@vger.kernel.org, virtualization@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, jasowang@redhat.com, kvm@vger.kernel.org, mst@redhat.com, syzkaller-bugs@googlegroups.com, Stefan Hajnoczi Subject: [PATCH RESEND net] vhost: fix vhost_vq_access_ok() log check Message-ID: <20180409174731-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20180409131021.5132-1-stefanha@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]); Mon, 09 Apr 2018 19:40:03 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Mon, 09 Apr 2018 19:40:03 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'mst@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 From: Stefan Hajnoczi Commit d65026c6c62e7d9616c8ceb5a53b68bcdc050525 ("vhost: validate log when IOTLB is enabled") introduced a regression. The logic was originally: if (vq->iotlb) return 1; return A && B; After the patch the short-circuit logic for A was inverted: if (A || vq->iotlb) return A; return B; The correct logic is: if (!A || vq->iotlb) return A; return B; Reported-by: syzbot+65a84dde0214b0387ccd@syzkaller.appspotmail.com Cc: Jason Wang Signed-off-by: Stefan Hajnoczi Acked-by: Michael S. Tsirkin --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 5320039671b7..f6af4210679a 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -1246,7 +1246,7 @@ int vhost_vq_access_ok(struct vhost_virtqueue *vq) { int ret = vq_log_access_ok(vq, vq->log_base); - if (ret || vq->iotlb) + if (!ret || vq->iotlb) return ret; return vq_access_ok(vq, vq->num, vq->desc, vq->avail, vq->used);