From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932113AbcCSC5W (ORCPT ); Fri, 18 Mar 2016 22:57:22 -0400 Received: from lists.s-osg.org ([54.187.51.154]:54798 "EHLO lists.s-osg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754303AbcCSC5P (ORCPT ); Fri, 18 Mar 2016 22:57:15 -0400 Date: Fri, 18 Mar 2016 23:57:08 -0300 From: Mauro Carvalho Chehab To: Shuah Khan Cc: tiwai@suse.com, perex@perex.cz, linux-media@vger.kernel.org, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] sound/usb: fix to release stream resources from media_snd_device_delete() Message-ID: <20160318235708.1eccf0e6@recife.lan> In-Reply-To: <1458355831-9467-1-git-send-email-shuahkh@osg.samsung.com> References: <1458355831-9467-1-git-send-email-shuahkh@osg.samsung.com> Organization: Samsung X-Mailer: Claws Mail 3.13.2 (GTK+ 2.24.30; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Fri, 18 Mar 2016 20:50:31 -0600 Shuah Khan 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 > --- > > - 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? Regards, Mauro > + } > > media_snd_mixer_delete(chip); > -- Thanks, Mauro