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Subject: Re: media: staging/imx: Improve pipeline searching (bug report)
To:     Colin Ian King <colin.king@canonical.com>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Shawn Guo <shawnguo@kernel.org>,
        Rui Miguel Silva <rmfrfs@gmail.com>,
        linux-media@vger.kernel.org, devel@driverdev.osuosl.org,
        linux-arm-kernel@lists.infradead.org
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
References: <9b6d7f0e-f191-e5d5-e20b-9244800678fe@canonical.com>
From:   Steve Longerbeam <slongerbeam@gmail.com>
Message-ID: <fa12f7f7-c2c8-6777-0359-8bdd8290f517@gmail.com>
Date:   Wed, 26 Jun 2019 11:35:38 -0700
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Thanks for catching,

On 6/26/19 11:27 AM, Colin Ian King wrote:
> Hi,
>
> Static analysis with Coverity on Linux next has found a potential issue
> with the following commit:
>
> commit 3ef46bc97ca2c918b7657a08220c7340a9bb07a2
> Author: Steve Longerbeam <slongerbeam@gmail.com>
> Date:   Fri May 10 17:50:11 2019 -0400
>
>      media: staging/imx: Improve pipeline searching
>
>
> The issue is in drivers/staging/media/imx/imx-media-utils.c in function
> find_pipeline_entity:
>
>          struct media_pad *pad = NULL;
>
> pad is assigned a NULL
>
>          struct video_device *vfd;
>          struct v4l2_subdev *sd;
>
>          if (grp_id && is_media_entity_v4l2_subdev(start)) {
>                  sd = media_entity_to_v4l2_subdev(start);
>                  if (sd->grp_id & grp_id)
>                          return &sd->entity;
>          } else if (buftype && is_media_entity_v4l2_video_device(start)) {
>                  vfd = media_entity_to_video_device(pad->entity);
>
> ..and above the null pad is being dereferenced causing a kernel oops.

yes, this is a typo and should be:

vfd = media_entity_to_video_device(start);


Sending a patch...

Steve