diff --git a/media/libmedia/IMediaSource.cpp b/media/libmedia/IMediaSource.cpp
index b18571f..36cd73b 100644
--- a/media/libmedia/IMediaSource.cpp
+++ b/media/libmedia/IMediaSource.cpp
@@ -107,7 +107,7 @@
         data.writeInterfaceToken(BpMediaSource::getInterfaceDescriptor());
         status_t ret = remote()->transact(GETFORMAT, data, &reply);
         if (ret == NO_ERROR) {
-            AutoMutex _l(mLock);
+            AutoMutex _l(mBpLock);
             mMetaData = MetaData::createFromParcel(reply);
             return mMetaData;
         }
@@ -224,7 +224,7 @@
     // XXX: could we use this for caching, or does metadata change on the fly?
     sp<MetaData> mMetaData;
     // ensure synchronize access to mMetaData
-    Mutex mLock;
+    Mutex mBpLock;
 
     // Cache all IMemory objects received from MediaExtractor.
     // We gc IMemory objects that are no longer active (referenced by a MediaBuffer).
@@ -301,6 +301,7 @@
             CHECK_INTERFACE(IMediaSource, data, reply);
             mGroup->signalBufferReturned(nullptr);
             status_t status = stop();
+            AutoMutex _l(mBnLock);
             mIndexCache.reset();
             mBuffersSinceStop = 0;
             return status;
@@ -340,6 +341,7 @@
                     && len == sizeof(opts)
                     && data.read((void *)&opts, len) == NO_ERROR;
 
+            AutoMutex _l(mBnLock);
             mGroup->signalBufferReturned(nullptr);
             mIndexCache.gc();
             size_t inlineTransferSize = 0;