From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932238AbdDGHlA (ORCPT ); Fri, 7 Apr 2017 03:41:00 -0400 Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:38404 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753972AbdDGHku (ORCPT ); Fri, 7 Apr 2017 03:40:50 -0400 Date: Fri, 7 Apr 2017 10:40:15 +0300 From: Sakari Ailus To: Helen Koike Cc: linux-media@vger.kernel.org, mchehab@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] [media] media-entity: only call dev_dbg_obj if mdev is not NULL Message-ID: <20170407074015.GB4192@valkosipuli.retiisi.org.uk> References: <1491507120-28112-1-git-send-email-helen.koike@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1491507120-28112-1-git-send-email-helen.koike@collabora.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Helen, On Thu, Apr 06, 2017 at 04:32:00PM -0300, Helen Koike wrote: > Fix kernel Oops NULL pointer deference > Call dev_dbg_obj only after checking if gobj->mdev is not NULL > > Signed-off-by: Helen Koike > --- > drivers/media/media-entity.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/media-entity.c b/drivers/media/media-entity.c > index 5640ca2..bc44193 100644 > --- a/drivers/media/media-entity.c > +++ b/drivers/media/media-entity.c > @@ -199,12 +199,12 @@ void media_gobj_create(struct media_device *mdev, > > void media_gobj_destroy(struct media_gobj *gobj) > { > - dev_dbg_obj(__func__, gobj); > - > /* Do nothing if the object is not linked. */ > if (gobj->mdev == NULL) > return; > > + dev_dbg_obj(__func__, gobj); > + > gobj->mdev->topology_version++; > > /* Remove the object from mdev list */ Where is media_gobj_destroy() called with an object with NULL mdev? I do not object to the change, but would like to know because I don't think it's supposed to happen. There are issues though, until the patches fixing object referencing are finished and merged. Unfortunately I haven't been able to work on those recently, will pick them up again soon... -- Kind regards, Sakari Ailus e-mail: sakari.ailus@iki.fi XMPP: sailus@retiisi.org.uk