Em Fri, 18 Mar 2016 23:57:08 -0300 Mauro Carvalho Chehab mchehab@osg.samsung.com escreveu:
Em Fri, 18 Mar 2016 20:50:31 -0600 Shuah Khan shuahkh@osg.samsung.com escreveu:
Fix to release stream resources from media_snd_device_delete() before media device is unregistered. Without this change, stream resource free is attempted after the media device is unregistered which would result in use-after-free errors.
Signed-off-by: Shuah Khan shuahkh@osg.samsung.com
- Ran bind/unbind loop (1000 iteration) test on snd-usb-audio while running mc_nextgen_test loop (1000 iterations) in parallel.
- Ran bind/unbind and rmmod/modprobe tests on both drivers. Also generated graphs when after bind/unbind, rmmod/modprobe. Graphs look good.
- Note: Please apply the following patch to fix memory leak: sound/usb: Fix memory leak in media_snd_stream_delete() during unbind https://lkml.org/lkml/2016/3/16/1050
sound/usb/media.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/sound/usb/media.c b/sound/usb/media.c index de4a815..e35af88 100644 --- a/sound/usb/media.c +++ b/sound/usb/media.c @@ -301,6 +301,13 @@ int media_snd_device_create(struct snd_usb_audio *chip, void media_snd_device_delete(struct snd_usb_audio *chip) { struct media_device *mdev = chip->media_dev;
- struct snd_usb_stream *stream;
- /* release resources */
- list_for_each_entry(stream, &chip->pcm_list, list) {
media_snd_stream_delete(&stream->substream[0]);media_snd_stream_delete(&stream->substream[1]);I'll look on it better tomorrow, but it sounds weird to hardcode substream[0] and [1] here... are you sure that this is valid for *all* devices supported by snd-usb-audio?
After looking at pcm.c and finding this:
static void snd_usb_audio_stream_free(struct snd_usb_stream *stream) { free_substream(&stream->substream[0]); free_substream(&stream->substream[1]); list_del(&stream->list); kfree(stream); }
It seems that assuming that substream is always an array with size 2 is right.
I'll do some tests with it today with your patch.
Regards, Mauro
Regards, Mauro
}
media_snd_mixer_delete(chip);