diff --git a/media/libstagefright/include/OMXNodeInstance.h b/media/libstagefright/include/OMXNodeInstance.h
index e5fb45b..babf5b7 100644
--- a/media/libstagefright/include/OMXNodeInstance.h
+++ b/media/libstagefright/include/OMXNodeInstance.h
@@ -187,7 +187,7 @@
 
     // For buffer id management
     OMX::buffer_id makeBufferID(OMX_BUFFERHEADERTYPE *bufferHeader);
-    OMX_BUFFERHEADERTYPE *findBufferHeader(OMX::buffer_id buffer);
+    OMX_BUFFERHEADERTYPE *findBufferHeader(OMX::buffer_id buffer, OMX_U32 portIndex);
     OMX::buffer_id findBufferID(OMX_BUFFERHEADERTYPE *bufferHeader);
     void invalidateBufferID(OMX::buffer_id buffer);
 
diff --git a/media/libstagefright/omx/OMXNodeInstance.cpp b/media/libstagefright/omx/OMXNodeInstance.cpp
index 8735eff..7f534b5e 100644
--- a/media/libstagefright/omx/OMXNodeInstance.cpp
+++ b/media/libstagefright/omx/OMXNodeInstance.cpp
@@ -101,19 +101,22 @@
 namespace android {
 
 struct BufferMeta {
-    BufferMeta(const sp<IMemory> &mem, bool is_backup = false)
+    BufferMeta(const sp<IMemory> &mem, OMX_U32 portIndex, bool is_backup = false)
         : mMem(mem),
-          mIsBackup(is_backup) {
+          mIsBackup(is_backup),
+          mPortIndex(portIndex) {
     }
 
-    BufferMeta(size_t size)
+    BufferMeta(size_t size, OMX_U32 portIndex)
         : mSize(size),
-          mIsBackup(false) {
+          mIsBackup(false),
+          mPortIndex(portIndex) {
     }
 
-    BufferMeta(const sp<GraphicBuffer> &graphicBuffer)
+    BufferMeta(const sp<GraphicBuffer> &graphicBuffer, OMX_U32 portIndex)
         : mGraphicBuffer(graphicBuffer),
-          mIsBackup(false) {
+          mIsBackup(false),
+          mPortIndex(portIndex) {
     }
 
     void CopyFromOMX(const OMX_BUFFERHEADERTYPE *header) {
@@ -160,11 +163,16 @@
         mGraphicBuffer = graphicBuffer;
     }
 
+    OMX_U32 getPortIndex() {
+        return mPortIndex;
+    }
+
 private:
     sp<GraphicBuffer> mGraphicBuffer;
     sp<IMemory> mMem;
     size_t mSize;
     bool mIsBackup;
+    OMX_U32 mPortIndex;
 
     BufferMeta(const BufferMeta &);
     BufferMeta &operator=(const BufferMeta &);
@@ -661,7 +669,7 @@
         return BAD_VALUE;
     }
 
-    BufferMeta *buffer_meta = new BufferMeta(params);
+    BufferMeta *buffer_meta = new BufferMeta(params, portIndex);
 
     OMX_BUFFERHEADERTYPE *header;
 
@@ -713,7 +721,7 @@
         return UNKNOWN_ERROR;
     }
 
-    BufferMeta *bufferMeta = new BufferMeta(graphicBuffer);
+    BufferMeta *bufferMeta = new BufferMeta(graphicBuffer, portIndex);
 
     OMX_BUFFERHEADERTYPE *header = NULL;
     OMX_U8* bufferHandle = const_cast<OMX_U8*>(
@@ -771,7 +779,7 @@
         return StatusFromOMXError(err);
     }
 
-    BufferMeta *bufferMeta = new BufferMeta(graphicBuffer);
+    BufferMeta *bufferMeta = new BufferMeta(graphicBuffer, portIndex);
 
     OMX_BUFFERHEADERTYPE *header;
 
@@ -812,6 +820,9 @@
 status_t OMXNodeInstance::updateGraphicBufferInMeta_l(
         OMX_U32 portIndex, const sp<GraphicBuffer>& graphicBuffer,
         OMX::buffer_id buffer, OMX_BUFFERHEADERTYPE *header) {
+    if (header == NULL) {
+        return BAD_VALUE;
+    }
     if (portIndex != kPortIndexInput && portIndex != kPortIndexOutput) {
         return BAD_VALUE;
     }
@@ -845,7 +856,7 @@
         OMX_U32 portIndex, const sp<GraphicBuffer>& graphicBuffer,
         OMX::buffer_id buffer) {
     Mutex::Autolock autoLock(mLock);
-    OMX_BUFFERHEADERTYPE *header = findBufferHeader(buffer);
+    OMX_BUFFERHEADERTYPE *header = findBufferHeader(buffer, portIndex);
     return updateGraphicBufferInMeta_l(portIndex, graphicBuffer, buffer, header);
 }
 
@@ -974,7 +985,7 @@
         void **buffer_data) {
     Mutex::Autolock autoLock(mLock);
 
-    BufferMeta *buffer_meta = new BufferMeta(size);
+    BufferMeta *buffer_meta = new BufferMeta(size, portIndex);
 
     OMX_BUFFERHEADERTYPE *header;
 
@@ -1015,7 +1026,7 @@
         return BAD_VALUE;
     }
 
-    BufferMeta *buffer_meta = new BufferMeta(params, true);
+    BufferMeta *buffer_meta = new BufferMeta(params, portIndex, true);
 
     OMX_BUFFERHEADERTYPE *header;
 
@@ -1056,7 +1067,10 @@
 
     removeActiveBuffer(portIndex, buffer);
 
-    OMX_BUFFERHEADERTYPE *header = findBufferHeader(buffer);
+    OMX_BUFFERHEADERTYPE *header = findBufferHeader(buffer, portIndex);
+    if (header == NULL) {
+        return BAD_VALUE;
+    }
     BufferMeta *buffer_meta = static_cast<BufferMeta *>(header->pAppPrivate);
 
     OMX_ERRORTYPE err = OMX_FreeBuffer(mHandle, portIndex, header);
@@ -1072,7 +1086,10 @@
 status_t OMXNodeInstance::fillBuffer(OMX::buffer_id buffer, int fenceFd) {
     Mutex::Autolock autoLock(mLock);
 
-    OMX_BUFFERHEADERTYPE *header = findBufferHeader(buffer);
+    OMX_BUFFERHEADERTYPE *header = findBufferHeader(buffer, kPortIndexOutput);
+    if (header == NULL) {
+        return BAD_VALUE;
+    }
     header->nFilledLen = 0;
     header->nOffset = 0;
     header->nFlags = 0;
@@ -1105,7 +1122,10 @@
         OMX_U32 flags, OMX_TICKS timestamp, int fenceFd) {
     Mutex::Autolock autoLock(mLock);
 
-    OMX_BUFFERHEADERTYPE *header = findBufferHeader(buffer);
+    OMX_BUFFERHEADERTYPE *header = findBufferHeader(buffer, kPortIndexInput);
+    if (header == NULL) {
+        return BAD_VALUE;
+    }
     BufferMeta *buffer_meta =
         static_cast<BufferMeta *>(header->pAppPrivate);
     sp<ABuffer> backup = buffer_meta->getBuffer(header, true /* backup */, false /* limit */);
@@ -1385,7 +1405,10 @@
 
     if (msg.type == omx_message::FILL_BUFFER_DONE) {
         OMX_BUFFERHEADERTYPE *buffer =
-            findBufferHeader(msg.u.extended_buffer_data.buffer);
+            findBufferHeader(msg.u.extended_buffer_data.buffer, kPortIndexOutput);
+        if (buffer == NULL) {
+            return false;
+        }
 
         {
             Mutex::Autolock _l(mDebugLock);
@@ -1416,7 +1439,10 @@
         }
     } else if (msg.type == omx_message::EMPTY_BUFFER_DONE) {
         OMX_BUFFERHEADERTYPE *buffer =
-            findBufferHeader(msg.u.buffer_data.buffer);
+            findBufferHeader(msg.u.buffer_data.buffer, kPortIndexInput);
+        if (buffer == NULL) {
+            return false;
+        }
 
         {
             Mutex::Autolock _l(mDebugLock);
@@ -1613,7 +1639,8 @@
     return buffer;
 }
 
-OMX_BUFFERHEADERTYPE *OMXNodeInstance::findBufferHeader(OMX::buffer_id buffer) {
+OMX_BUFFERHEADERTYPE *OMXNodeInstance::findBufferHeader(
+        OMX::buffer_id buffer, OMX_U32 portIndex) {
     if (buffer == 0) {
         return NULL;
     }
@@ -1623,7 +1650,15 @@
         CLOGW("findBufferHeader: buffer %u not found", buffer);
         return NULL;
     }
-    return mBufferIDToBufferHeader.valueAt(index);
+    OMX_BUFFERHEADERTYPE *header = mBufferIDToBufferHeader.valueAt(index);
+    BufferMeta *buffer_meta =
+        static_cast<BufferMeta *>(header->pAppPrivate);
+    if (buffer_meta->getPortIndex() != portIndex) {
+        CLOGW("findBufferHeader: buffer %u found but with incorrect port index.", buffer);
+        android_errorWriteLog(0x534e4554, "28816827");
+        return NULL;
+    }
+    return header;
 }
 
 OMX::buffer_id OMXNodeInstance::findBufferID(OMX_BUFFERHEADERTYPE *bufferHeader) {