Fix issue 2107584: media server crash when AudioFlinger fails to allocate memory for track control block.

AudioFlinger: verify that mCblk is not null before using it in Track and RecordTrack contructors.
IAudioFlinger: check result of remote transaction before reading IAudioTrack and IAudioRecord.
IAudioTrack and IAudioRecord: check result of remote transaction before reading IMemory.

1 files changed, 6 insertions, 2 deletions

diff --git a/media/libmedia/IAudioTrack.cpp b/media/libmedia/IAudioTrack.cpp
index 75b861b..7f43347 100644
--- a/media/libmedia/IAudioTrack.cpp
+++ b/media/libmedia/IAudioTrack.cpp
@@ -81,9 +81,13 @@ public:
     virtual sp<IMemory> getCblk() const
     {
         Parcel data, reply;
+        sp<IMemory> cblk;
         data.writeInterfaceToken(IAudioTrack::getInterfaceDescriptor());
-        remote()->transact(GET_CBLK, data, &reply);
-        return interface_cast<IMemory>(reply.readStrongBinder());
+        status_t status = remote()->transact(GET_CBLK, data, &reply);
+        if (status == NO_ERROR) {
+            cblk = interface_cast<IMemory>(reply.readStrongBinder());
+        }
+        return cblk;
     }    
 };