diff --git a/manager/app/src/main/java/me/weishu/kernelsu/ui/webui/WebUIActivity.kt b/manager/app/src/main/java/me/weishu/kernelsu/ui/webui/WebUIActivity.kt
index d926d7eada35..188615977178 100644
--- a/manager/app/src/main/java/me/weishu/kernelsu/ui/webui/WebUIActivity.kt
+++ b/manager/app/src/main/java/me/weishu/kernelsu/ui/webui/WebUIActivity.kt
@@ -15,15 +15,13 @@ import androidx.core.view.ViewCompat
 import androidx.core.view.WindowInsetsCompat
 import androidx.core.view.updateLayoutParams
 import androidx.webkit.WebViewAssetLoader
-import com.topjohnwu.superuser.Shell
 import me.weishu.kernelsu.ui.util.createRootShell
 import java.io.File
 
 @SuppressLint("SetJavaScriptEnabled")
 class WebUIActivity : ComponentActivity() {
-    private lateinit var webviewInterface: WebViewInterface
-
-    private var rootShell: Shell? = null
+    private val rootShell by lazy { createRootShell(true) }
+    private var webView = null as WebView?
 
     override fun onCreate(savedInstanceState: Bundle?) {
 
@@ -35,8 +33,8 @@ class WebUIActivity : ComponentActivity() {
 
         super.onCreate(savedInstanceState)
 
-        val moduleId = intent.getStringExtra("id")!!
-        val name = intent.getStringExtra("name")!!
+        val moduleId = intent.getStringExtra("id") ?: finishAndRemoveTask().let { return }
+        val name = intent.getStringExtra("name") ?: finishAndRemoveTask().let { return }
         if (Build.VERSION.SDK_INT < Build.VERSION_CODES.TIRAMISU) {
             @Suppress("DEPRECATION")
             setTaskDescription(ActivityManager.TaskDescription("KernelSU - $name"))
@@ -50,7 +48,6 @@ class WebUIActivity : ComponentActivity() {
 
         val moduleDir = "/data/adb/modules/${moduleId}"
         val webRoot = File("${moduleDir}/webroot")
-        val rootShell = createRootShell(true).also { this.rootShell = it }
         val webViewAssetLoader = WebViewAssetLoader.Builder()
             .setDomain("mui.kernelsu.org")
             .addPathHandler(
@@ -69,6 +66,8 @@ class WebUIActivity : ComponentActivity() {
         }
 
         val webView = WebView(this).apply {
+            webView = this
+
             ViewCompat.setOnApplyWindowInsetsListener(this) { view, insets ->
                 val inset = insets.getInsets(WindowInsetsCompat.Type.systemBars())
                 view.updateLayoutParams<MarginLayoutParams> {
@@ -82,8 +81,7 @@ class WebUIActivity : ComponentActivity() {
             settings.javaScriptEnabled = true
             settings.domStorageEnabled = true
             settings.allowFileAccess = false
-            webviewInterface = WebViewInterface(this@WebUIActivity, this, moduleDir)
-            addJavascriptInterface(webviewInterface, "ksu")
+            addJavascriptInterface(WebViewInterface(this@WebUIActivity, this, moduleDir), "ksu")
             setWebViewClient(webViewClient)
             loadUrl("https://mui.kernelsu.org/index.html")
         }
@@ -92,7 +90,13 @@ class WebUIActivity : ComponentActivity() {
     }
 
     override fun onDestroy() {
+        rootShell.runCatching { close() }
+        webView?.apply {
+            stopLoading()
+            removeAllViews()
+            destroy()
+            webView = null
+        }
         super.onDestroy()
-        runCatching { rootShell?.close() }
     }
 }
\ No newline at end of file
diff --git a/manager/app/src/main/java/me/weishu/kernelsu/ui/webui/WebViewInterface.kt b/manager/app/src/main/java/me/weishu/kernelsu/ui/webui/WebViewInterface.kt
index 00fcde653b60..baa2b2aa1578 100644
--- a/manager/app/src/main/java/me/weishu/kernelsu/ui/webui/WebViewInterface.kt
+++ b/manager/app/src/main/java/me/weishu/kernelsu/ui/webui/WebViewInterface.kt
@@ -22,6 +22,7 @@ import org.json.JSONObject
 import java.io.File
 import java.util.concurrent.CompletableFuture
 
+@Suppress("unused")
 class WebViewInterface(
     val context: Context,
     private val webView: WebView,
@@ -61,56 +62,56 @@ class WebViewInterface(
         options: String?,
         callbackFunc: String
     ) {
-        val finalCommand = StringBuilder()
-        processOptions(finalCommand, options)
-        finalCommand.append(cmd)
+        val finalCommand = buildString {
+            processOptions(this, options)
+            append(cmd)
+        }
 
         val result = withNewRootShell(true) {
-            newJob().add(finalCommand.toString()).to(ArrayList(), ArrayList()).exec()
+            newJob().add(finalCommand).to(ArrayList(), ArrayList()).exec()
         }
         val stdout = result.out.joinToString(separator = "\n")
         val stderr = result.err.joinToString(separator = "\n")
 
         val jsCode =
-            "javascript: (function() { try { ${callbackFunc}(${result.code}, ${
+            "(function() { try { ${callbackFunc}(${result.code}, ${
                 JSONObject.quote(
                     stdout
                 )
             }, ${JSONObject.quote(stderr)}); } catch(e) { console.error(e); } })();"
         webView.post {
-            webView.loadUrl(jsCode)
+            webView.evaluateJavascript(jsCode, null)
         }
     }
 
     @JavascriptInterface
     fun spawn(command: String, args: String, options: String?, callbackFunc: String) {
-        val finalCommand = StringBuilder()
-
-        processOptions(finalCommand, options)
-
-        if (!TextUtils.isEmpty(args)) {
-            finalCommand.append(command).append(" ")
-            JSONArray(args).let { argsArray ->
-                for (i in 0 until argsArray.length()) {
-                    finalCommand.append(argsArray.getString(i))
-                    finalCommand.append(" ")
+        val finalCommand = buildString {
+            processOptions(this, options)
+
+            if (!TextUtils.isEmpty(args)) {
+                append(command).append(" ")
+                JSONArray(args).let { argsArray ->
+                    for (i in 0 until argsArray.length()) {
+                        append("${argsArray.getString(i)} ")
+                    }
                 }
+            } else {
+                append(command)
             }
-        } else {
-            finalCommand.append(command)
         }
 
         val shell = createRootShell(true)
 
         val emitData = fun(name: String, data: String) {
             val jsCode =
-                "javascript: (function() { try { ${callbackFunc}.${name}.emit('data', ${
+                "(function() { try { ${callbackFunc}.${name}.emit('data', ${
                     JSONObject.quote(
                         data
                     )
                 }); } catch(e) { console.error('emitData', e); } })();"
             webView.post {
-                webView.loadUrl(jsCode)
+                webView.evaluateJavascript(jsCode, null)
             }
         }
 
@@ -126,21 +127,21 @@ class WebViewInterface(
             }
         }
 
-        val future = shell.newJob().add(finalCommand.toString()).to(stdout, stderr).enqueue()
+        val future = shell.newJob().add(finalCommand).to(stdout, stderr).enqueue()
         val completableFuture = CompletableFuture.supplyAsync {
             future.get()
         }
 
         completableFuture.thenAccept { result ->
             val emitExitCode =
-                "javascript: (function() { try { ${callbackFunc}.emit('exit', ${result.code}); } catch(e) { console.error(`emitExit error: \${e}`); } })();"
+                $$"(function() { try { $${callbackFunc}.emit('exit', $${result.code}); } catch(e) { console.error(`emitExit error: ${e}`); } })();"
             webView.post {
-                webView.loadUrl(emitExitCode)
+                webView.evaluateJavascript(emitExitCode, null)
             }
 
             if (result.code != 0) {
                 val emitErrCode =
-                    "javascript: (function() { try { var err = new Error(); err.exitCode = ${result.code}; err.message = ${
+                    "(function() { try { var err = new Error(); err.exitCode = ${result.code}; err.message = ${
                         JSONObject.quote(
                             result.err.joinToString(
                                 "\n"
@@ -148,7 +149,7 @@ class WebViewInterface(
                         )
                     };${callbackFunc}.emit('error', err); } catch(e) { console.error('emitErr', e); } })();"
                 webView.post {
-                    webView.loadUrl(emitErrCode)
+                    webView.evaluateJavascript(emitErrCode, null)
                 }
             }
         }.whenComplete { _, _ ->
@@ -179,7 +180,7 @@ class WebViewInterface(
     @JavascriptInterface
     fun moduleInfo(): String {
         val moduleInfos = JSONArray(listModules())
-        var currentModuleInfo = JSONObject()
+        val currentModuleInfo = JSONObject()
         currentModuleInfo.put("moduleDir", modDir)
         val moduleId = File(modDir).getName()
         for (i in 0 until moduleInfos.length()) {
@@ -189,7 +190,7 @@ class WebViewInterface(
                 continue
             }
 
-            var keys = currentInfo.keys()
+            val keys = currentInfo.keys()
             for (key in keys) {
                 currentModuleInfo.put(key, currentInfo.get(key))
             }