diff --git a/cmds/stagefright/SineSource.cpp b/cmds/stagefright/SineSource.cpp
index 0ecc16c..0656030 100644
--- a/cmds/stagefright/SineSource.cpp
+++ b/cmds/stagefright/SineSource.cpp
@@ -63,12 +63,15 @@
         MediaBufferBase **out, const ReadOptions * /* options */) {
     *out = NULL;
 
-    MediaBufferBase *buffer;
+    MediaBufferBase *buffer = nullptr;
     status_t err = mGroup->acquire_buffer(&buffer);
 
     if (err != OK) {
         return err;
     }
+    if (buffer == nullptr) {
+        return AMEDIA_ERROR_UNKNOWN;
+    }
 
     size_t frameSize = mNumChannels * sizeof(int16_t);
     size_t numFramesPerBuffer = buffer->size() / frameSize;
diff --git a/cmds/stagefright/record.cpp b/cmds/stagefright/record.cpp
index 5743ad6..87e8832 100644
--- a/cmds/stagefright/record.cpp
+++ b/cmds/stagefright/record.cpp
@@ -89,6 +89,9 @@
         if (err != OK) {
             return err;
         }
+        if (buffer == nullptr) {
+            return AMEDIA_ERROR_UNKNOWN;
+        }
 
         char x = (char)((double)rand() / RAND_MAX * 255);
         memset((*buffer)->data(), x, mSize);
diff --git a/media/module/extractors/aac/AACExtractor.cpp b/media/module/extractors/aac/AACExtractor.cpp
index 2fc4584..a44fb61 100644
--- a/media/module/extractors/aac/AACExtractor.cpp
+++ b/media/module/extractors/aac/AACExtractor.cpp
@@ -310,9 +310,9 @@
         return AMEDIA_ERROR_END_OF_STREAM;
     }
 
-    MediaBufferHelper *buffer;
+    MediaBufferHelper *buffer = nullptr;
     status_t err = mBufferGroup->acquire_buffer(&buffer);
-    if (err != OK) {
+    if (err != OK || buffer == nullptr) {
         return AMEDIA_ERROR_UNKNOWN;
     }
 
diff --git a/media/module/extractors/amr/AMRExtractor.cpp b/media/module/extractors/amr/AMRExtractor.cpp
index e26ff0a..b0f69ce 100644
--- a/media/module/extractors/amr/AMRExtractor.cpp
+++ b/media/module/extractors/amr/AMRExtractor.cpp
@@ -341,9 +341,9 @@
         return AMEDIA_ERROR_MALFORMED;
     }
 
-    MediaBufferHelper *buffer;
+    MediaBufferHelper *buffer = nullptr;
     status_t err = mBufferGroup->acquire_buffer(&buffer);
-    if (err != OK) {
+    if (err != OK || buffer == nullptr) {
         return AMEDIA_ERROR_UNKNOWN;
     }
 
diff --git a/media/module/extractors/flac/FLACExtractor.cpp b/media/module/extractors/flac/FLACExtractor.cpp
index ec7cb24..2434e41 100644
--- a/media/module/extractors/flac/FLACExtractor.cpp
+++ b/media/module/extractors/flac/FLACExtractor.cpp
@@ -614,9 +614,9 @@
     }
     // acquire a media buffer
     CHECK(mGroup != NULL);
-    MediaBufferHelper *buffer;
+    MediaBufferHelper *buffer = nullptr;
     status_t err = mGroup->acquire_buffer(&buffer);
-    if (err != OK) {
+    if (err != OK || buffer == nullptr) {
         return NULL;
     }
     const size_t bufferSize = blocksize * getChannels() * getOutputSampleSize();
diff --git a/media/module/extractors/midi/MidiExtractor.cpp b/media/module/extractors/midi/MidiExtractor.cpp
index d0efb2f..167cc40 100644
--- a/media/module/extractors/midi/MidiExtractor.cpp
+++ b/media/module/extractors/midi/MidiExtractor.cpp
@@ -240,9 +240,9 @@
     if ((state == EAS_STATE_STOPPED) || (state == EAS_STATE_ERROR)) {
         return NULL;
     }
-    MediaBufferHelper *buffer;
+    MediaBufferHelper *buffer = nullptr;
     status_t err = mGroup->acquire_buffer(&buffer);
-    if (err != OK) {
+    if (err != OK || buffer == nullptr) {
         ALOGE("readBuffer: no buffer");
         return NULL;
     }
diff --git a/media/module/extractors/mkv/MatroskaExtractor.cpp b/media/module/extractors/mkv/MatroskaExtractor.cpp
index 443e26c..2b72387 100644
--- a/media/module/extractors/mkv/MatroskaExtractor.cpp
+++ b/media/module/extractors/mkv/MatroskaExtractor.cpp
@@ -790,6 +790,7 @@
     int64_t timeUs = mBlockIter.blockTimeUs();
 
     for (int i = 0; i < block->GetFrameCount(); ++i) {
+        status_t err;
         MatroskaExtractor::TrackInfo *trackInfo = &mExtractor->mTracks.editItemAt(mTrackIndex);
         const mkvparser::Block::Frame &frame = block->GetFrame(i);
         size_t len = frame.len;
@@ -798,8 +799,13 @@
         }
 
         len += trackInfo->mHeaderLen;
-        MediaBufferHelper *mbuf;
-        mBufferGroup->acquire_buffer(&mbuf, false /* nonblocking */, len /* requested size */);
+        MediaBufferHelper *mbuf = nullptr;
+        err = mBufferGroup->acquire_buffer(&mbuf, false /* nonblocking */,
+                                           len /* requested size */);
+        if (err != OK || mbuf == nullptr) {
+            ALOGE("readBlock: no buffer");
+            return AMEDIA_ERROR_UNKNOWN;
+        }
         mbuf->set_range(0, len);
         uint8_t *data = static_cast<uint8_t *>(mbuf->data());
         if (trackInfo->mHeader) {
@@ -832,7 +838,7 @@
             }
         }
 
-        status_t err = frame.Read(mExtractor->mReader, data + trackInfo->mHeaderLen);
+        err = frame.Read(mExtractor->mReader, data + trackInfo->mHeaderLen);
         if (err == OK
                 && mExtractor->mIsWebm
                 && trackInfo->mEncrypted) {
diff --git a/media/module/extractors/mp3/MP3Extractor.cpp b/media/module/extractors/mp3/MP3Extractor.cpp
index 248a39c..328b790 100644
--- a/media/module/extractors/mp3/MP3Extractor.cpp
+++ b/media/module/extractors/mp3/MP3Extractor.cpp
@@ -521,9 +521,9 @@
         mSamplesRead = 0;
     }
 
-    MediaBufferHelper *buffer;
+    MediaBufferHelper *buffer = nullptr;
     status_t err = mBufferGroup->acquire_buffer(&buffer);
-    if (err != OK) {
+    if (err != OK || buffer == nullptr) {
         return AMEDIA_ERROR_UNKNOWN;
     }
 
diff --git a/media/module/extractors/mp4/MPEG4Extractor.cpp b/media/module/extractors/mp4/MPEG4Extractor.cpp
index 3a5a869..1d88785 100644
--- a/media/module/extractors/mp4/MPEG4Extractor.cpp
+++ b/media/module/extractors/mp4/MPEG4Extractor.cpp
@@ -6337,7 +6337,7 @@
 
         err = mBufferGroup->acquire_buffer(&mBuffer);
 
-        if (err != OK) {
+        if (err != OK || mBuffer == nullptr) {
             CHECK(mBuffer == NULL);
             return AMEDIA_ERROR_UNKNOWN;
         }
diff --git a/media/module/extractors/mpeg2/MPEG2PSExtractor.cpp b/media/module/extractors/mpeg2/MPEG2PSExtractor.cpp
index afd28ef..44c8937 100644
--- a/media/module/extractors/mpeg2/MPEG2PSExtractor.cpp
+++ b/media/module/extractors/mpeg2/MPEG2PSExtractor.cpp
@@ -699,11 +699,26 @@
         }
     }
 
-    MediaBufferBase *mbuf;
-    mSource->read(&mbuf, (MediaTrack::ReadOptions*) options);
+    MediaBufferBase *mbuf = nullptr;
+    status_t err_read = mSource->read(&mbuf, (MediaTrack::ReadOptions*) options);
+    if (mbuf == nullptr) {
+        ALOGE("Track::read: null buffer read from source");
+        return AMEDIA_ERROR_UNKNOWN;
+    }
+    if (err_read != OK) {
+        ALOGE("Track::read: no buffer read from source");
+        mbuf->release();
+        return AMEDIA_ERROR_UNKNOWN;
+    }
+
     size_t length = mbuf->range_length();
-    MediaBufferHelper *outbuf;
-    mBufferGroup->acquire_buffer(&outbuf, false, length);
+    MediaBufferHelper *outbuf = nullptr;
+    status_t err = mBufferGroup->acquire_buffer(&outbuf, false, length);
+    if (err != OK || outbuf == nullptr) {
+        ALOGE("Track::read: no buffer");
+        mbuf->release();
+        return AMEDIA_ERROR_UNKNOWN;
+    }
     memcpy(outbuf->data(), mbuf->data(), length);
     outbuf->set_range(0, length);
     *buffer = outbuf;
diff --git a/media/module/extractors/mpeg2/MPEG2TSExtractor.cpp b/media/module/extractors/mpeg2/MPEG2TSExtractor.cpp
index 9a3cd92..736b817 100644
--- a/media/module/extractors/mpeg2/MPEG2TSExtractor.cpp
+++ b/media/module/extractors/mpeg2/MPEG2TSExtractor.cpp
@@ -182,11 +182,26 @@
         return AMEDIA_ERROR_END_OF_STREAM;
     }
 
-    MediaBufferBase *mbuf;
-    mImpl->read(&mbuf, (MediaTrack::ReadOptions*) options);
+    MediaBufferBase *mbuf = nullptr;
+    status_t err_read = mImpl->read(&mbuf, (MediaTrack::ReadOptions*) options);
+    if (mbuf == nullptr) {
+        ALOGE("Track::read: null buffer read from source");
+        return AMEDIA_ERROR_UNKNOWN;
+    }
+    if (err_read != OK) {
+        ALOGE("Track::read: no buffer read from source");
+        mbuf->release();
+        return AMEDIA_ERROR_UNKNOWN;
+    }
+
     size_t length = mbuf->range_length();
-    MediaBufferHelper *outbuf;
-    mBufferGroup->acquire_buffer(&outbuf, false, length);
+    MediaBufferHelper *outbuf = nullptr;
+    status_t err = mBufferGroup->acquire_buffer(&outbuf, false, length);
+    if (err != OK || outbuf == nullptr) {
+        ALOGE("read: no buffer");
+        mbuf->release();
+        return AMEDIA_ERROR_UNKNOWN;
+    }
     memcpy(outbuf->data(), mbuf->data(), length);
     outbuf->set_range(0, length);
     *out = outbuf;
diff --git a/media/module/extractors/ogg/OggExtractor.cpp b/media/module/extractors/ogg/OggExtractor.cpp
index eb2246d..1c6f516 100644
--- a/media/module/extractors/ogg/OggExtractor.cpp
+++ b/media/module/extractors/ogg/OggExtractor.cpp
@@ -790,7 +790,8 @@
             }
             MediaBufferHelper *tmp;
             if (mBufferGroup) {
-                mBufferGroup->acquire_buffer(&tmp, false, fullSize);
+                // ignore return code here. instead, check tmp below.
+                (void) mBufferGroup->acquire_buffer(&tmp, false, fullSize);
                 ALOGV("acquired buffer %p from group", tmp);
             } else {
                 tmp = new StandAloneMediaBuffer(fullSize);
@@ -924,13 +925,16 @@
 status_t MyOggExtractor::init() {
     AMediaFormat_setString(mMeta, AMEDIAFORMAT_KEY_MIME, mMimeType);
 
-    media_status_t err;
-    MediaBufferHelper *packet;
     for (size_t i = 0; i < mNumHeaders; ++i) {
+        media_status_t err;
+        MediaBufferHelper *packet = nullptr;
         // ignore timestamp for configuration packets
         if ((err = _readNextPacket(&packet, /* calcVorbisTimestamp = */ false)) != AMEDIA_OK) {
             return err;
         }
+        if (packet == nullptr) {
+            return AMEDIA_ERROR_UNKNOWN;
+        }
         ALOGV("read packet of size %zu\n", packet->range_length());
         err = verifyHeader(packet, /* type = */ i * 2 + 1);
         packet->release();
diff --git a/media/module/extractors/wav/WAVExtractor.cpp b/media/module/extractors/wav/WAVExtractor.cpp
index 9e94587..9c3bac6 100644
--- a/media/module/extractors/wav/WAVExtractor.cpp
+++ b/media/module/extractors/wav/WAVExtractor.cpp
@@ -459,11 +459,15 @@
         mCurrentPos = pos + mOffset;
     }
 
-    MediaBufferHelper *buffer;
+    MediaBufferHelper *buffer = nullptr;
     media_status_t err = mBufferGroup->acquire_buffer(&buffer);
     if (err != OK) {
         return err;
     }
+    if (buffer == nullptr) {
+        ALOGE("acquire_buffer OK, but no buffer");
+        return AMEDIA_ERROR_UNKNOWN;
+    }
 
     // maxBytesToRead may be reduced so that in-place data conversion will fit in buffer size.
     const size_t bufferSize = std::min(buffer->size(), kMaxFrameSize);