Address review comments

Author: jadhavrohit924

src/app/clusters/mode-select-server/mode-select-server.cpp

@@ -49,7 +49,7 @@ using BootReasonType = GeneralDiagnostics::BootReasonEnum;
 
 static InteractionModel::Status verifyModeValue(const EndpointId endpointId, const uint8_t newMode);
 
-ModeSelect::SupportedModesManager * sSupportedModesManager = nullptr;
+static ModeSelect::SupportedModesManager * sSupportedModesManager = nullptr;
 
 const SupportedModesManager * ModeSelect::getSupportedModesManager()
 {
@@ -82,6 +82,12 @@ CHIP_ERROR ModeSelectAttrAccess::Read(const ConcreteReadAttributePath & aPath, A
 
     if (ModeSelect::Attributes::SupportedModes::Id == aPath.mAttributeId)
     {
+        if (gSupportedModeManager == nullptr)
+        {
+            ChipLogError(Zcl, "ModeSelect: SupportedModesManager is NULL");
+            aEncoder.EncodeEmptyList();
+            return CHIP_NO_ERROR;
+        }
         const ModeSelect::SupportedModesManager::ModeOptionsProvider modeOptionsProvider =
             gSupportedModeManager->getModeOptionsProvider(aPath.mEndpointId);
         if (modeOptionsProvider.begin() == nullptr)
@@ -115,8 +121,14 @@ bool emberAfModeSelectClusterChangeToModeCallback(CommandHandler * commandHandle
     uint8_t newMode       = commandData.newMode;
     // Check that the newMode matches one of the supported options
     const ModeSelect::Structs::ModeOptionStruct::Type * modeOptionPtr;
-    Status checkSupportedModeStatus =
-        ModeSelect::getSupportedModesManager()->getModeOptionByMode(endpointId, newMode, &modeOptionPtr);
+    const ModeSelect::SupportedModesManager * gSupportedModeManager = ModeSelect::getSupportedModesManager();
+    if (gSupportedModeManager == nullptr)
+    {
+        ChipLogError(Zcl, "ModeSelect: SupportedModesManager is NULL");
+        commandHandler->AddStatus(commandPath, Status::Failure);
+        return true;
+    }
+    Status checkSupportedModeStatus = gSupportedModeManager->getModeOptionByMode(endpointId, newMode, &modeOptionPtr);
     if (Status::Success != checkSupportedModeStatus)
     {
         ChipLogProgress(Zcl, "ModeSelect: Failed to find the option with mode %u", newMode);
@@ -276,5 +288,11 @@ static InteractionModel::Status verifyModeValue(const EndpointId endpointId, con
         return InteractionModel::Status::Success;
     }
     const ModeSelect::Structs::ModeOptionStruct::Type * modeOptionPtr;
-    return ModeSelect::getSupportedModesManager()->getModeOptionByMode(endpointId, newMode, &modeOptionPtr);
+    const ModeSelect::SupportedModesManager * gSupportedModeManager = ModeSelect::getSupportedModesManager();
+    if (gSupportedModeManager == nullptr)
+    {
+        ChipLogError(Zcl, "ModeSelect: SupportedModesManager is NULL");
+        return Status::Failure;
+    }
+    return gSupportedModeManager->getModeOptionByMode(endpointId, newMode, &modeOptionPtr);
 }