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| author | Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> | 2021-09-24 14:24:14 -0500 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2021-09-28 10:20:25 +0200 |
| commit | 1465d06a6d8580e73ae65f8590392df58c5ed2fd (patch) | |
| tree | 042c8e47d7288fa496cd4158997243d54636d0ad /sound/hda/hdac_stream.c | |
| parent | 882e013a32ecdad7877bfb1669cd51ee052f3369 (diff) | |
| download | lwn-1465d06a6d8580e73ae65f8590392df58c5ed2fd.tar.gz lwn-1465d06a6d8580e73ae65f8590392df58c5ed2fd.zip | |
ALSA: hda: hdac_stream: fix potential locking issue in snd_hdac_stream_assign()
The fields 'opened', 'running', 'assigned_key' are all protected by a
spinlock, but the spinlock is not taken when looking for a
stream. This can result in a possible race between assign() and
release().
Fix by taking the spinlock before walking through the bus stream list.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210924192417.169243-2-pierre-louis.bossart@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/hda/hdac_stream.c')
| -rw-r--r-- | sound/hda/hdac_stream.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/sound/hda/hdac_stream.c b/sound/hda/hdac_stream.c index 1eb8563db2df..9867555883c3 100644 --- a/sound/hda/hdac_stream.c +++ b/sound/hda/hdac_stream.c @@ -296,6 +296,7 @@ struct hdac_stream *snd_hdac_stream_assign(struct hdac_bus *bus, int key = (substream->pcm->device << 16) | (substream->number << 2) | (substream->stream + 1); + spin_lock_irq(&bus->reg_lock); list_for_each_entry(azx_dev, &bus->stream_list, list) { if (azx_dev->direction != substream->stream) continue; @@ -309,13 +310,12 @@ struct hdac_stream *snd_hdac_stream_assign(struct hdac_bus *bus, res = azx_dev; } if (res) { - spin_lock_irq(&bus->reg_lock); res->opened = 1; res->running = 0; res->assigned_key = key; res->substream = substream; - spin_unlock_irq(&bus->reg_lock); } + spin_unlock_irq(&bus->reg_lock); return res; } EXPORT_SYMBOL_GPL(snd_hdac_stream_assign); |