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

[Shuah Khan]

On 01/28/2016 09:44 AM, Mauro Carvalho Chehab wrote:
> Em Wed,  6 Jan 2016 13:27:13 -0700
> Shuah Khan <shuahkh at osg.samsung.com> 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.

ok will merge it.

thanks,
-- Shuah
> 
>>
>> Signed-off-by: Shuah Khan <shuahkh at osg.samsung.com>
>> ---
>>  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) {


-- 
Shuah Khan
Sr. Linux Kernel Developer
Open Source Innovation Group
Samsung Research America (Silicon Valley)
shuahkh at osg.samsung.com | (970) 217-8978