ALSA: pcm: use lock to protect substream runtime resource
Use a spinlock to protect runtime resource in substream
against race conditions which may lead to use-after-free.
CRs-fixed: 2112713
Change-Id: I37dee68cad5eae05b21cfade3dabc0c2b79be6b8
Signed-off-by: Karthikeyan Mani <kmani@codeaurora.org>
diff --git a/sound/core/pcm_timer.c b/sound/core/pcm_timer.c
index 20ecd8f..5258ecc 100644
--- a/sound/core/pcm_timer.c
+++ b/sound/core/pcm_timer.c
@@ -65,9 +65,16 @@
static unsigned long snd_pcm_timer_resolution(struct snd_timer * timer)
{
struct snd_pcm_substream *substream;
+ unsigned long ret = 0, flags = 0;
substream = timer->private_data;
- return substream->runtime ? substream->runtime->timer_resolution : 0;
+ spin_lock_irqsave(&substream->runtime_lock, flags);
+ if (substream->runtime)
+ ret = substream->runtime->timer_resolution;
+ else
+ ret = 0;
+ spin_unlock_irqrestore(&substream->runtime_lock, flags);
+ return ret;
}
static int snd_pcm_timer_start(struct snd_timer * timer)