From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752242AbcEMJJ2 (ORCPT ); Fri, 13 May 2016 05:09:28 -0400 Received: from lb3-smtp-cloud3.xs4all.net ([194.109.24.30]:41301 "EHLO lb3-smtp-cloud3.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751651AbcEMJJ0 (ORCPT ); Fri, 13 May 2016 05:09:26 -0400 Subject: Re: [PATCH v2 1/2] vb2: core: Skip planes array verification if pb is NULL To: Sakari Ailus , linux-media@vger.kernel.org References: <1463055292-25053-1-git-send-email-sakari.ailus@linux.intel.com> <1463055292-25053-2-git-send-email-sakari.ailus@linux.intel.com> Cc: mchehab@osg.samsung.com, david@unsolicited.net, linux-kernel@vger.kernel.org From: Hans Verkuil Message-ID: <573599BF.4050708@xs4all.nl> Date: Fri, 13 May 2016 11:09:19 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Icedove/38.7.2 MIME-Version: 1.0 In-Reply-To: <1463055292-25053-2-git-send-email-sakari.ailus@linux.intel.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/12/2016 02:14 PM, Sakari Ailus wrote: > An earlier patch fixing an input validation issue introduced another > issue: vb2_core_dqbuf() is called with pb argument value NULL in some > cases, causing a NULL pointer dereference. Fix this by skipping the > verification as there's nothing to verify. > > Signed-off-by: David R > > Use if () instead of ? :; it's nicer that way. Improve the comment in the > code as well. This comment doesn't seem applicable to this patch. Reviewed-by: Hans Verkuil Hans > > Fixes: e7e0c3e26587 ("[media] videobuf2-core: Check user space planes array in dqbuf") > > Signed-off-by: Sakari Ailus > Cc: stable@vger.kernel.org # for v4.4 and later > --- > drivers/media/v4l2-core/videobuf2-core.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c > index 9fbcb67..633fc1a 100644 > --- a/drivers/media/v4l2-core/videobuf2-core.c > +++ b/drivers/media/v4l2-core/videobuf2-core.c > @@ -1648,7 +1648,7 @@ static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, > void *pb, int nonblocking) > { > unsigned long flags; > - int ret; > + int ret = 0; > > /* > * Wait for at least one buffer to become available on the done_list. > @@ -1664,10 +1664,12 @@ static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, > spin_lock_irqsave(&q->done_lock, flags); > *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry); > /* > - * Only remove the buffer from done_list if v4l2_buffer can handle all > - * the planes. > + * Only remove the buffer from done_list if all planes can be > + * handled. Some cases such as V4L2 file I/O and DVB have pb > + * == NULL; skip the check then as there's nothing to verify. > */ > - ret = call_bufop(q, verify_planes_array, *vb, pb); > + if (pb) > + ret = call_bufop(q, verify_planes_array, *vb, pb); > if (!ret) > list_del(&(*vb)->done_entry); > spin_unlock_irqrestore(&q->done_lock, flags); >