Bug#637740: [PATCH] uvcvideo: Fix crash when linking entities
On Wed, Sep 07, 2011 at 12:29:08AM +0200, Laurent Pinchart wrote:
> The uvc_mc_register_entity() function wrongfully selects the
> media_entity associated with a UVC entity when creating links. This
> results in access to uninitialized media_entity structures and can hit a
> BUG_ON statement in media_entity_create_link(). Fix it.
>
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> ---
> drivers/media/video/uvc/uvc_entity.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> This patch should fix a v3.0 regression that results in a kernel crash as
> reported in http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=637740 and
> https://bugzilla.redhat.com/show_bug.cgi?id=735437.
>
> Test results will be welcome.
I built a test kernel for Fedora with the patch and the submitter of the
above bug has reported that the issue seems to be fixed.
josh
> diff --git a/drivers/media/video/uvc/uvc_entity.c b/drivers/media/video/uvc/uvc_entity.c
> index 48fea37..29e2399 100644
> --- a/drivers/media/video/uvc/uvc_entity.c
> +++ b/drivers/media/video/uvc/uvc_entity.c
> @@ -49,7 +49,7 @@ static int uvc_mc_register_entity(struct uvc_video_chain *chain,
> if (remote == NULL)
> return -EINVAL;
>
> - source = (UVC_ENTITY_TYPE(remote) != UVC_TT_STREAMING)
> + source = (UVC_ENTITY_TYPE(remote) == UVC_TT_STREAMING)
> ? (remote->vdev ? &remote->vdev->entity : NULL)
> : &remote->subdev.entity;
> if (source == NULL)
> --
> Regards,
>
> Laurent Pinchart
>
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