diff --git a/tv/hdmi/connection/aidl/default/HdmiConnectionMock.cpp b/tv/hdmi/connection/aidl/default/HdmiConnectionMock.cpp
index ca8c348..8f4411b 100644
--- a/tv/hdmi/connection/aidl/default/HdmiConnectionMock.cpp
+++ b/tv/hdmi/connection/aidl/default/HdmiConnectionMock.cpp
@@ -70,16 +70,21 @@
 }
 
 ScopedAStatus HdmiConnectionMock::setHpdSignal(HpdSignal signal, int32_t portId) {
-    if (mHdmiThreadRun) {
-        mHpdSignal.at(portId - 1) = signal;
-        return ScopedAStatus::ok();
-    } else {
+    if (portId > mTotalPorts || portId < 1) {
+        return ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+    if (!mHdmiThreadRun) {
         return ScopedAStatus::fromServiceSpecificError(
                 static_cast<int32_t>(Result::FAILURE_INVALID_STATE));
     }
+    mHpdSignal.at(portId - 1) = signal;
+    return ScopedAStatus::ok();
 }
 
 ScopedAStatus HdmiConnectionMock::getHpdSignal(int32_t portId, HpdSignal* _aidl_return) {
+    if (portId > mTotalPorts || portId < 1) {
+        return ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
     *_aidl_return = mHpdSignal.at(portId - 1);
     return ScopedAStatus::ok();
 }
@@ -123,7 +128,7 @@
     bool connected = ((msgBuf[3]) & 0xf) > 0;
     int32_t portId = static_cast<uint32_t>(msgBuf[0] & 0xf);
 
-    if (portId > static_cast<int32_t>(mPortInfos.size())) {
+    if (portId > static_cast<int32_t>(mPortInfos.size()) || portId < 1) {
         ALOGD("[halimp_aidl] ignore hot plug message, id %x does not exist", portId);
         return;
     }