From: Takashi Iwai <tiwai@suse.de>
To: paulhsia <paulhsia@chromium.org>
Cc: alsa-devel@alsa-project.org, Mark Brown <broonie@kernel.org>,
linux-kernel@vger.kernel.org, Takashi Iwai <tiwai@suse.com>
Subject: Re: [alsa-devel] [PATCH 0/2] ALSA: pcm: Fix race condition in runtime access
Date: Tue, 12 Nov 2019 19:16:50 +0100 [thread overview]
Message-ID: <s5h1rud7yel.wl-tiwai@suse.de> (raw)
In-Reply-To: <20191112171715.128727-1-paulhsia@chromium.org>
On Tue, 12 Nov 2019 18:17:13 +0100,
paulhsia wrote:
>
> Since
> - snd_pcm_detach_substream sets runtime to null without stream lock and
> - snd_pcm_period_elapsed checks the nullity of the runtime outside of
> stream lock.
>
> This will trigger null memory access in snd_pcm_running() call in
> snd_pcm_period_elapsed.
Well, if a stream is detached, it means that the stream must have been
already closed; i.e. it's already a clear bug in the driver that
snd_pcm_period_elapsed() is called against such a stream.
Or am I missing other possible case?
thanks,
Takashi
>
> paulhsia (2):
> ALSA: pcm: Fix stream lock usage in snd_pcm_period_elapsed()
> ALSA: pcm: Use stream lock in snd_pcm_detach_substream()
>
> sound/core/pcm.c | 8 +++++++-
> sound/core/pcm_lib.c | 8 ++++++--
> 2 files changed, 13 insertions(+), 3 deletions(-)
>
> --
> 2.24.0.rc1.363.gb1bccd3e3d-goog
>
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next prev parent reply other threads:[~2019-11-12 18:17 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-12 17:17 [alsa-devel] [PATCH 0/2] ALSA: pcm: Fix race condition in runtime access paulhsia
2019-11-12 17:17 ` [alsa-devel] [PATCH 1/2] ALSA: pcm: Fix stream lock usage in snd_pcm_period_elapsed() paulhsia
2019-11-12 17:17 ` [alsa-devel] [PATCH 2/2] ALSA: pcm: Use stream lock in snd_pcm_detach_substream() paulhsia
2019-11-12 18:16 ` Takashi Iwai [this message]
2019-11-13 7:24 ` [alsa-devel] [PATCH 0/2] ALSA: pcm: Fix race condition in runtime access Chih-Yang Hsia
2019-11-13 9:47 ` Takashi Iwai
2019-11-13 11:36 ` Takashi Iwai
2019-11-14 14:16 ` Chih-Yang Hsia
2019-11-14 14:20 ` Takashi Iwai
2019-11-14 16:37 ` Chih-Yang Hsia
2019-11-14 17:00 ` Takashi Iwai
2019-11-15 15:36 ` Chih-Yang Hsia
[not found] ` <CAJaf1Ta1tqYMCTaWxeL82gfY8Fg6hidLjHO3FFiqU7yyn5oVPg@mail.gmail.com>
[not found] ` <s5hy2whi1gw.wl-tiwai@suse.de>
2019-11-15 17:04 ` Chih-Yang Hsia
2019-11-15 17:07 ` Takashi Iwai
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