Re: [PATCH 24/31] media: au0828 fix null pointer reference in au0828_create_media_graph()

[Mauro Carvalho Chehab]

Em Wed,  6 Jan 2016 13:27:13 -0700
Shuah Khan <shuahkh@xxxxxxxxxxxxxxx> escreveu:

> Add a new wrapper function to au0828_create_media_graph()
> to be called as an entity_notify function to fix null
> pointer dereference. A rebasing mistake resulted in
> registering au0828_create_media_graph() without the
> correct parameters which lead to the following
> null pointer dereference:
> 
> [   69.006164] Call Trace:
> [   69.006169]  [<ffffffff81a9a1b0>] dump_stack+0x44/0x64
> [   69.006175]  [<ffffffff81503af9>] print_trailer+0xf9/0x150
> [   69.006180]  [<ffffffff81509284>] object_err+0x34/0x40
> [   69.006185]  [<ffffffff815063c4>] ? ___slab_alloc+0x4c4/0x4e0
> [   69.006190]  [<ffffffff8150b732>] kasan_report_error+0x212/0x520
> [   69.006196]  [<ffffffff815063c4>] ? ___slab_alloc+0x4c4/0x4e0
> [   69.006201]  [<ffffffff8150ba83>] __asan_report_load1_noabort+0x43/0x50
> [   69.006208]  [<ffffffffa0d30991>] ? au0828_create_media_graph+0x641/0x730 [au0828]
> [   69.006215]  [<ffffffffa0d30991>] au0828_create_media_graph+0x641/0x730 [au0828]
> [   69.006221]  [<ffffffff82245c3d>] media_device_register_entity+0x33d/0x4f0
> [   69.006234]  [<ffffffffa0ebeb1c>] media_stream_init+0x2ac/0x610 [snd_usb_audio]
> [   69.006247]  [<ffffffffa0ea9a70>] snd_usb_pcm_open+0xcd0/0x1280 [snd_usb_audio]

Please merge the fix with the patch that caused the regression.

> 
> Signed-off-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx>
> ---
>  drivers/media/usb/au0828/au0828-core.c | 16 +++++++++++++++-
>  1 file changed, 15 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/usb/au0828/au0828-core.c b/drivers/media/usb/au0828/au0828-core.c
> index f8d2db3..9497ad1 100644
> --- a/drivers/media/usb/au0828/au0828-core.c
> +++ b/drivers/media/usb/au0828/au0828-core.c
> @@ -370,6 +370,20 @@ static int au0828_create_media_graph(struct au0828_dev *dev)
>  	return 0;
>  }
>  
> +void au0828_create_media_graph_notify(struct media_entity *new,
> +				      void *notify_data)
> +{
> +#ifdef CONFIG_MEDIA_CONTROLLER
> +	struct au0828_dev *dev = (struct au0828_dev *) notify_data;
> +	int ret;
> +
> +	ret = au0828_create_media_graph(dev);
> +	if (ret)
> +		pr_err("%s() media graph create failed for new entity %s\n",
> +		       __func__, new->name);
> +#endif
> +}
> +
>  static int au0828_enable_source(struct media_entity *entity,
>  				struct media_pipeline *pipe)
>  {
> @@ -535,7 +549,7 @@ static int au0828_media_device_register(struct au0828_dev *dev,
>  	}
>  	/* register entity_notify callback */
>  	dev->entity_notify.notify_data = (void *) dev;
> -	dev->entity_notify.notify = (void *) au0828_create_media_graph;
> +	dev->entity_notify.notify = au0828_create_media_graph_notify;
>  	ret = media_device_register_entity_notify(dev->media_dev,
>  						  &dev->entity_notify);
>  	if (ret) {