diff --git a/nci/jni/NfcTag.cpp b/nci/jni/NfcTag.cpp
old mode 100755
new mode 100644
index 3246f6f..0e70707
--- a/nci/jni/NfcTag.cpp
+++ b/nci/jni/NfcTag.cpp
@@ -21,6 +21,7 @@
 #include "NfcTag.h"
 #include "JavaClassConstants.h"
 #include "config.h"
+#include <log/log.h>
 #include <ScopedLocalRef.h>
 #include <ScopedPrimitiveArray.h>
 
@@ -741,7 +742,14 @@
                 *****************/
                 ALOGV("%s: tech B; TARGET_TYPE_ISO14443_3B", fn);
                 len = mTechParams [i].param.pb.sensb_res_len;
-                len = len - 4; //subtract 4 bytes for NFCID0 at byte 2 through 5
+                if (len >= NFC_NFCID0_MAX_LEN) {
+                    // subtract 4 bytes for NFCID0 at byte 2 through 5
+                    len = len - NFC_NFCID0_MAX_LEN;
+                } else {
+                    android_errorWriteLog(0x534e4554, "124940143");
+                    ALOGE("%s: sensb_res_len error", fn);
+                    len = 0;
+                }
                 pollBytes.reset(e->NewByteArray(len));
                 e->SetByteArrayRegion(pollBytes.get(), 0, len, (jbyte*) (mTechParams [i].param.pb.sensb_res+4));
             }