From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BC0DAC43381 for ; Mon, 25 Mar 2019 11:49:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8135D20850 for ; Mon, 25 Mar 2019 11:49:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730970AbfCYLto (ORCPT ); Mon, 25 Mar 2019 07:49:44 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38504 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730730AbfCYLto (ORCPT ); Mon, 25 Mar 2019 07:49:44 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DF4BB31408F1; Mon, 25 Mar 2019 11:49:43 +0000 (UTC) Received: from maximlenovopc.usersys.redhat.com (unknown [10.35.206.72]) by smtp.corp.redhat.com (Postfix) with ESMTP id B18B46766F; Mon, 25 Mar 2019 11:49:37 +0000 (UTC) Message-ID: <01d3cd705b9ec9d5d6b286381951e6168269bda6.camel@redhat.com> Subject: Re: [PATCH 2/8] vfio/mdev: Avoid release parent reference during error path From: Maxim Levitsky To: Parav Pandit , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, kwankhede@nvidia.com, alex.williamson@redhat.com Date: Mon, 25 Mar 2019 13:49:36 +0200 In-Reply-To: <1553296835-37522-3-git-send-email-parav@mellanox.com> References: <1553296835-37522-1-git-send-email-parav@mellanox.com> <1553296835-37522-3-git-send-email-parav@mellanox.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Mon, 25 Mar 2019 11:49:43 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2019-03-22 at 18:20 -0500, Parav Pandit wrote: > During mdev parent registration in mdev_register_device(), > if parent device is duplicate, it releases the reference of existing > parent device. > This is incorrect. Existing parent device should not be touched. > > Fixes: 7b96953bc640 ("vfio: Mediated device Core driver") > Signed-off-by: Parav Pandit > --- > drivers/vfio/mdev/mdev_core.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c > index 3e5880a..4f213e4d 100644 > --- a/drivers/vfio/mdev/mdev_core.c > +++ b/drivers/vfio/mdev/mdev_core.c > @@ -182,6 +182,7 @@ int mdev_register_device(struct device *dev, const struct > mdev_parent_ops *ops) > /* Check for duplicate */ > parent = __find_parent_device(dev); > if (parent) { > + parent = NULL; > ret = -EEXIST; > goto add_dev_err; > } This is also clearly an issue. Reviewed-by: Maxim Levitsky Best regards, Maxim Levitsky