On Mon, 13 Jan 2020 13:59:51 +0800, Chuhong Yuan wrote:
> allegro_open() misses checks for v4l2_m2m_ctx_init() and results of
> v4l2_ctrl_new* calls.
> Add checks and error handlers to fix the problems.
>
> Signed-off-by: Chuhong Yuan <hslester96@xxxxxxxxx>
> ---
> Changes in v3:
> - Make code cleaner.
> - Add a check for handler->error.
>
> .../staging/media/allegro-dvt/allegro-core.c | 24 +++++++++++++++----
> 1 file changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/staging/media/allegro-dvt/allegro-core.c b/drivers/staging/media/allegro-dvt/allegro-core.c
> index 6f0cd0784786..e86001e42963 100644
> --- a/drivers/staging/media/allegro-dvt/allegro-core.c
> +++ b/drivers/staging/media/allegro-dvt/allegro-core.c
> @@ -2270,15 +2270,12 @@ static int allegro_open(struct file *file)
> struct allegro_channel *channel = NULL;
> struct v4l2_ctrl_handler *handler;
> u64 mask;
> + int ret;
>
> channel = kzalloc(sizeof(*channel), GFP_KERNEL);
> if (!channel)
> return -ENOMEM;
>
> - v4l2_fh_init(&channel->fh, vdev);
> - file->private_data = &channel->fh;
> - v4l2_fh_add(&channel->fh);
> -
> init_completion(&channel->completion);
>
> channel->dev = dev;
> @@ -2328,6 +2325,11 @@ static int allegro_open(struct file *file)
> V4L2_CID_MIN_BUFFERS_FOR_OUTPUT,
> 1, 32,
> 1, 1);
> + if (handler->error != 0) {
> + ret = handler->error;
> + goto error;
> + }
> +
> channel->fh.ctrl_handler = handler;
>
> channel->mcu_channel_id = -1;
> @@ -2341,7 +2343,21 @@ static int allegro_open(struct file *file)
> channel->fh.m2m_ctx = v4l2_m2m_ctx_init(dev->m2m_dev, channel,
> allegro_queue_init);
>
> + if (IS_ERR(channel->fh.m2m_ctx)) {
> + ret = PTR_ERR(channel->fh.m2m_ctx);
> + goto error;
> + }
> +
> + v4l2_fh_init(&channel->fh, vdev);
This call sets channel->fh.ctrl_handler to vdev->ctrl_handler, which
has previously been overriden by the driver to handler. Therefore, this
patch breaks all controls. I think we should initialize channel->fh
before setting any fields of this struct.
Michael
> + file->private_data = &channel->fh;
> + v4l2_fh_add(&channel->fh);
> +
> return 0;
> +
> +error:
> + v4l2_ctrl_handler_free(handler);
> + kfree(channel);
> + return ret;
> }
>
> static int allegro_release(struct file *file)
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