From: Pierre-Louis Bossart pierre-louis.bossart@linux.intel.com
stable inclusion form stable-v5.10.82 commit 6718f79c40fd9f2788b0d12deb64562fcbece984 bugzilla: 185877 https://gitee.com/openeuler/kernel/issues/I4QU6V
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
--------------------------------
commit 1465d06a6d8580e73ae65f8590392df58c5ed2fd upstream.
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... Signed-off-by: Takashi Iwai tiwai@suse.de Cc: Scott Bruce smbruce@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- sound/hda/hdac_stream.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/sound/hda/hdac_stream.c b/sound/hda/hdac_stream.c index abe7a1b16fe1..ce77a5320163 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);