audio: fix crash when starting capture

When starting capture, we check if a playback stream is active with an
incompatible sampling rate and if yes force this stream in standby.
The output stream lock is acquired while requesting standby. The problem
is that this stream is referenced by adev->active_out which is cleared by
do_output_standby() and a crash occurs when releasing the lock.

The same problem is present when starting a playback stream and a capture
stream is active.

Change-Id: I72ce058308371199655e3b2e1cfc0529328555ec

1 files changed, 12 insertions, 10 deletions

diff --git a/audio/audio_hw.c b/audio/audio_hw.c
index 3182c00..5159cb5 100644
--- a/audio/audio_hw.c
+++ b/audio/audio_hw.c
@@ -281,13 +281,14 @@ static int start_output_stream(struct stream_out *out)
      * the most common rate, but group 2 is required for SCO.
      */
     if (adev->active_in) {
-        pthread_mutex_lock(&adev->active_in->lock);
+        struct stream_in *in = adev->active_in;
+        pthread_mutex_lock(&in->lock);
         if (((out->pcm_config->rate % 8000 == 0) &&
-                 (adev->active_in->pcm_config->rate % 8000) != 0) ||
+                 (in->pcm_config->rate % 8000) != 0) ||
                  ((out->pcm_config->rate % 11025 == 0) &&
-                 (adev->active_in->pcm_config->rate % 11025) != 0))
-            do_in_standby(adev->active_in);
-        pthread_mutex_unlock(&adev->active_in->lock);
+                 (in->pcm_config->rate % 11025) != 0))
+            do_in_standby(in);
+        pthread_mutex_unlock(&in->lock);
     }
 
     out->pcm = pcm_open(PCM_CARD, device, PCM_OUT | PCM_NORESTART, out->pcm_config);
@@ -348,13 +349,14 @@ static int start_input_stream(struct stream_in *in)
      * the most common rate, but group 2 is required for SCO.
      */
     if (adev->active_out) {
-        pthread_mutex_lock(&adev->active_out->lock);
+        struct stream_out *out = adev->active_out;
+        pthread_mutex_lock(&out->lock);
         if (((in->pcm_config->rate % 8000 == 0) &&
-                 (adev->active_out->pcm_config->rate % 8000) != 0) ||
+                 (out->pcm_config->rate % 8000) != 0) ||
                  ((in->pcm_config->rate % 11025 == 0) &&
-                 (adev->active_out->pcm_config->rate % 11025) != 0))
-            do_out_standby(adev->active_out);
-        pthread_mutex_unlock(&adev->active_out->lock);
+                 (out->pcm_config->rate % 11025) != 0))
+            do_out_standby(out);
+        pthread_mutex_unlock(&out->lock);
     }
 
     in->pcm = pcm_open(PCM_CARD, device, PCM_IN, in->pcm_config);