diff --git a/media/libstagefright/MPEG4Extractor.cpp b/media/libstagefright/MPEG4Extractor.cpp
index e4f8384..f8789da 100755
--- a/media/libstagefright/MPEG4Extractor.cpp
+++ b/media/libstagefright/MPEG4Extractor.cpp
@@ -4228,7 +4228,15 @@
                     continue;
                 }
 
-                CHECK(dstOffset + 4 <= mBuffer->size());
+                if (dstOffset > SIZE_MAX - 4 ||
+                        dstOffset + 4 > SIZE_MAX - nalLength ||
+                        dstOffset + 4 + nalLength > mBuffer->size()) {
+                    ALOGE("b/27208621 : %zu %zu", dstOffset, mBuffer->size());
+                    android_errorWriteLog(0x534e4554, "27208621");
+                    mBuffer->release();
+                    mBuffer = NULL;
+                    return ERROR_MALFORMED;
+                }
 
                 dstData[dstOffset++] = 0;
                 dstData[dstOffset++] = 0;