diff --git a/services/audioflinger/AudioFlinger.cpp b/services/audioflinger/AudioFlinger.cpp
index 39f04fb..3b90073 100644
--- a/services/audioflinger/AudioFlinger.cpp
+++ b/services/audioflinger/AudioFlinger.cpp
@@ -2887,6 +2887,8 @@
     }
 
     {
+        Mutex::Autolock _l(mLock);
+
         if (!EffectsFactoryHalInterface::isNullUuid(&pDesc->uuid)) {
             // if uuid is specified, request effect descriptor
             lStatus = mEffectsFactoryHal->getDescriptor(&pDesc->uuid, &desc);
@@ -2942,6 +2944,8 @@
                 desc = d;
             }
         }
+    }
+    {
 
         // Do not allow auxiliary effects on a session different from 0 (output mix)
         if (sessionId != AUDIO_SESSION_OUTPUT_MIX &&