diff --git a/media/libaudioclient/AudioRecord.cpp b/media/libaudioclient/AudioRecord.cpp
index a1b04ca..271e186 100644
--- a/media/libaudioclient/AudioRecord.cpp
+++ b/media/libaudioclient/AudioRecord.cpp
@@ -884,7 +884,6 @@
 {
     // previous and new IAudioRecord sequence numbers are used to detect track re-creation
     uint32_t oldSequence = 0;
-    uint32_t newSequence;
 
     Proxy::Buffer buffer;
     status_t status = NO_ERROR;
@@ -902,7 +901,7 @@
             // start of lock scope
             AutoMutex lock(mLock);
 
-            newSequence = mSequence;
+            uint32_t newSequence = mSequence;
             // did previous obtainBuffer() fail due to media server death or voluntary invalidation?
             if (status == DEAD_OBJECT) {
                 // re-create track, unless someone else has already done so
@@ -939,6 +938,7 @@
     audioBuffer->frameCount = buffer.mFrameCount;
     audioBuffer->size = buffer.mFrameCount * mFrameSize;
     audioBuffer->raw = buffer.mRaw;
+    audioBuffer->sequence = oldSequence;
     if (nonContig != NULL) {
         *nonContig = buffer.mNonContig;
     }
@@ -959,6 +959,12 @@
     buffer.mRaw = audioBuffer->raw;
 
     AutoMutex lock(mLock);
+    if (audioBuffer->sequence != mSequence) {
+        // This Buffer came from a different IAudioRecord instance, so ignore the releaseBuffer
+        ALOGD("%s is no-op due to IAudioRecord sequence mismatch %u != %u",
+                __func__, audioBuffer->sequence, mSequence);
+        return;
+    }
     mInOverrun = false;
     mProxy->releaseBuffer(&buffer);
 
diff --git a/media/libaudioclient/AudioTrack.cpp b/media/libaudioclient/AudioTrack.cpp
index 4a80cd3..9a66d48 100644
--- a/media/libaudioclient/AudioTrack.cpp
+++ b/media/libaudioclient/AudioTrack.cpp
@@ -1665,7 +1665,6 @@
 {
     // previous and new IAudioTrack sequence numbers are used to detect track re-creation
     uint32_t oldSequence = 0;
-    uint32_t newSequence;
 
     Proxy::Buffer buffer;
     status_t status = NO_ERROR;
@@ -1682,7 +1681,7 @@
         {   // start of lock scope
             AutoMutex lock(mLock);
 
-            newSequence = mSequence;
+            uint32_t newSequence = mSequence;
             // did previous obtainBuffer() fail due to media server death or voluntary invalidation?
             if (status == DEAD_OBJECT) {
                 // re-create track, unless someone else has already done so
@@ -1729,6 +1728,7 @@
     audioBuffer->frameCount = buffer.mFrameCount;
     audioBuffer->size = buffer.mFrameCount * mFrameSize;
     audioBuffer->raw = buffer.mRaw;
+    audioBuffer->sequence = oldSequence;
     if (nonContig != NULL) {
         *nonContig = buffer.mNonContig;
     }
@@ -1752,6 +1752,12 @@
     buffer.mRaw = audioBuffer->raw;
 
     AutoMutex lock(mLock);
+    if (audioBuffer->sequence != mSequence) {
+        // This Buffer came from a different IAudioTrack instance, so ignore the releaseBuffer
+        ALOGD("%s is no-op due to IAudioTrack sequence mismatch %u != %u",
+                __func__, audioBuffer->sequence, mSequence);
+        return;
+    }
     mReleased += stepCount;
     mInUnderrun = false;
     mProxy->releaseBuffer(&buffer);
diff --git a/media/libaudioclient/include/media/AudioRecord.h b/media/libaudioclient/include/media/AudioRecord.h
index a3c0fe4..574302b 100644
--- a/media/libaudioclient/include/media/AudioRecord.h
+++ b/media/libaudioclient/include/media/AudioRecord.h
@@ -92,6 +92,11 @@
             int8_t*     i8;         // unsigned 8-bit, offset by 0x80
                                     // input to obtainBuffer(): unused, output: pointer to buffer
         };
+
+        uint32_t    sequence;       // IAudioRecord instance sequence number, as of obtainBuffer().
+                                    // It is set by obtainBuffer() and confirmed by releaseBuffer().
+                                    // Not "user-serviceable".
+                                    // TODO Consider sp<IMemory> instead, or in addition to this.
     };
 
     /* As a convenience, if a callback is supplied, a handler thread
@@ -420,14 +425,17 @@
      *  frameCount  number of frames requested
      *  size        ignored
      *  raw         ignored
+     *  sequence    ignored
      * After error return:
      *  frameCount  0
      *  size        0
      *  raw         undefined
+     *  sequence    undefined
      * After successful return:
      *  frameCount  actual number of frames available, <= number requested
      *  size        actual number of bytes available
      *  raw         pointer to the buffer
+     *  sequence    IAudioRecord instance sequence number, as of obtainBuffer()
      */
 
             status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount,
diff --git a/media/libaudioclient/include/media/AudioTrack.h b/media/libaudioclient/include/media/AudioTrack.h
index df5eabc..c607918 100644
--- a/media/libaudioclient/include/media/AudioTrack.h
+++ b/media/libaudioclient/include/media/AudioTrack.h
@@ -107,6 +107,11 @@
             int16_t*    i16;      // signed 16-bit
             int8_t*     i8;       // unsigned 8-bit, offset by 0x80
         };                        // input to obtainBuffer(): unused, output: pointer to buffer
+
+        uint32_t    sequence;       // IAudioTrack instance sequence number, as of obtainBuffer().
+                                    // It is set by obtainBuffer() and confirmed by releaseBuffer().
+                                    // Not "user-serviceable".
+                                    // TODO Consider sp<IMemory> instead, or in addition to this.
     };
 
     /* As a convenience, if a callback is supplied, a handler thread
@@ -692,14 +697,17 @@
      *  frameCount  number of [empty slots for] frames requested
      *  size        ignored
      *  raw         ignored
+     *  sequence    ignored
      * After error return:
      *  frameCount  0
      *  size        0
      *  raw         undefined
+     *  sequence    undefined
      * After successful return:
      *  frameCount  actual number of [empty slots for] frames available, <= number requested
      *  size        actual number of bytes available
      *  raw         pointer to the buffer
+     *  sequence    IAudioTrack instance sequence number, as of obtainBuffer()
      */
             status_t    obtainBuffer(Buffer* audioBuffer, int32_t waitCount,
                                 size_t *nonContig = NULL);