diff --git a/core/java/android/app/assist/AssistStructure.java b/core/java/android/app/assist/AssistStructure.java
index 93836263..bf715c3 100644
--- a/core/java/android/app/assist/AssistStructure.java
+++ b/core/java/android/app/assist/AssistStructure.java
@@ -2058,6 +2058,16 @@
         return mActivityComponent;
     }
 
+    /**
+     * Called by Autofill server when app forged a different value.
+     *
+     * @hide
+     */
+    public void setActivityComponent(ComponentName componentName) {
+        ensureData();
+        mActivityComponent = componentName;
+    }
+
     /** @hide */
     public int getFlags() {
         return mFlags;
diff --git a/core/java/android/view/autofill/AutofillManager.java b/core/java/android/view/autofill/AutofillManager.java
index 4fb2a99..ba738b6 100644
--- a/core/java/android/view/autofill/AutofillManager.java
+++ b/core/java/android/view/autofill/AutofillManager.java
@@ -24,6 +24,8 @@
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.annotation.SystemService;
+import android.app.Activity;
+import android.content.ComponentName;
 import android.content.Context;
 import android.content.Intent;
 import android.content.IntentSender;
@@ -44,6 +46,7 @@
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.logging.MetricsLogger;
 import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
+import com.android.internal.util.Preconditions;
 
 import java.io.PrintWriter;
 import java.lang.annotation.Retention;
@@ -390,7 +393,7 @@
      * @hide
      */
     public AutofillManager(Context context, IAutoFillManager service) {
-        mContext = context;
+        mContext = Preconditions.checkNotNull(context, "context cannot be null");
         mService = service;
     }
 
@@ -940,6 +943,13 @@
         return mContext.getAutofillClient();
     }
 
+    private ComponentName getComponentNameFromContext() {
+        if (mContext instanceof Activity) {
+            return ((Activity) mContext).getComponentName();
+        }
+        return null;
+    }
+
     /** @hide */
     public void onAuthenticationResult(int authenticationId, Intent data) {
         if (!hasAutofillFeature()) {
@@ -990,9 +1000,14 @@
             return;
         }
         try {
+            final ComponentName componentName = getComponentNameFromContext();
+            if (componentName == null) {
+                Log.w(TAG, "startSessionLocked(): context is not activity: " + mContext);
+                return;
+            }
             mSessionId = mService.startSession(mContext.getActivityToken(),
                     mServiceClient.asBinder(), id, bounds, value, mContext.getUserId(),
-                    mCallback != null, flags, mContext.getOpPackageName());
+                    mCallback != null, flags, componentName);
             if (mSessionId != NO_SESSION) {
                 mState = STATE_ACTIVE;
             }
@@ -1050,9 +1065,14 @@
 
         try {
             if (restartIfNecessary) {
+                final ComponentName componentName = getComponentNameFromContext();
+                if (componentName == null) {
+                    Log.w(TAG, "startSessionLocked(): context is not activity: " + mContext);
+                    return;
+                }
                 final int newId = mService.updateOrRestartSession(mContext.getActivityToken(),
                         mServiceClient.asBinder(), id, bounds, value, mContext.getUserId(),
-                        mCallback != null, flags, mContext.getOpPackageName(), mSessionId, action);
+                        mCallback != null, flags, componentName, mSessionId, action);
                 if (newId != mSessionId) {
                     if (sDebug) Log.d(TAG, "Session restarted: " + mSessionId + "=>" + newId);
                     mSessionId = newId;
diff --git a/core/java/android/view/autofill/IAutoFillManager.aidl b/core/java/android/view/autofill/IAutoFillManager.aidl
index 6bd9bec..9329c4d 100644
--- a/core/java/android/view/autofill/IAutoFillManager.aidl
+++ b/core/java/android/view/autofill/IAutoFillManager.aidl
@@ -16,6 +16,7 @@
 
 package android.view.autofill;
 
+import android.content.ComponentName;
 import android.graphics.Rect;
 import android.os.Bundle;
 import android.os.IBinder;
@@ -34,14 +35,15 @@
     int addClient(in IAutoFillManagerClient client, int userId);
     int startSession(IBinder activityToken, in IBinder appCallback, in AutofillId autoFillId,
             in Rect bounds, in AutofillValue value, int userId, boolean hasCallback, int flags,
-            String packageName);
+            in ComponentName componentName);
     FillEventHistory getFillEventHistory();
     boolean restoreSession(int sessionId, in IBinder activityToken, in IBinder appCallback);
     void updateSession(int sessionId, in AutofillId id, in Rect bounds,
             in AutofillValue value, int action, int flags, int userId);
     int updateOrRestartSession(IBinder activityToken, in IBinder appCallback,
             in AutofillId autoFillId, in Rect bounds, in AutofillValue value, int userId,
-            boolean hasCallback, int flags, String packageName, int sessionId, int action);
+            boolean hasCallback, int flags, in ComponentName componentName, int sessionId,
+            int action);
     void finishSession(int sessionId, int userId);
     void cancelSession(int sessionId, int userId);
     void setAuthenticationResult(in Bundle data, int sessionId, int authenticationId, int userId);
diff --git a/proto/src/metrics_constants.proto b/proto/src/metrics_constants.proto
index cbd2f75..fef8696 100644
--- a/proto/src/metrics_constants.proto
+++ b/proto/src/metrics_constants.proto
@@ -4006,6 +4006,19 @@
     // OS: O
     FIELD_NOTIFICATION_GROUP_SUMMARY = 947;
 
+    // An app attempted to forge a different component name in the AssisStructure that would be
+    // passed to the autofill service.
+    // OS: O (security patch)
+    // Package: Real package of the app being autofilled
+    // Tag FIELD_AUTOFILL_SERVICE: Package of the autofill service that processed the request
+    // TAG FIELD_AUTOFILL_FORGED_COMPONENT_NAME: Component name being forged
+    AUTOFILL_FORGED_COMPONENT_ATTEMPT = 948;
+
+    // FIELD - The component that an app tried tro forged.
+    // Type: string
+    // OS: O (security patch)
+    FIELD_AUTOFILL_FORGED_COMPONENT_NAME = 949;
+
     // ---- End O Constants, all O constants go above this line ----
 
     // OPEN: Settings > System > Languages & input > Advanced > Lift to open camera
diff --git a/services/autofill/java/com/android/server/autofill/AutofillManagerService.java b/services/autofill/java/com/android/server/autofill/AutofillManagerService.java
index 1f4161ac..ffc778a 100644
--- a/services/autofill/java/com/android/server/autofill/AutofillManagerService.java
+++ b/services/autofill/java/com/android/server/autofill/AutofillManagerService.java
@@ -533,25 +533,26 @@
         @Override
         public int startSession(IBinder activityToken, IBinder appCallback, AutofillId autofillId,
                 Rect bounds, AutofillValue value, int userId, boolean hasCallback, int flags,
-                String packageName) {
+                ComponentName componentName) {
 
             activityToken = Preconditions.checkNotNull(activityToken, "activityToken");
             appCallback = Preconditions.checkNotNull(appCallback, "appCallback");
             autofillId = Preconditions.checkNotNull(autofillId, "autoFillId");
-            packageName = Preconditions.checkNotNull(packageName, "packageName");
+            componentName = Preconditions.checkNotNull(componentName, "componentName");
+            final String packageName = Preconditions.checkNotNull(componentName.getPackageName());
 
             Preconditions.checkArgument(userId == UserHandle.getUserId(getCallingUid()), "userId");
 
             try {
                 mContext.getPackageManager().getPackageInfoAsUser(packageName, 0, userId);
             } catch (PackageManager.NameNotFoundException e) {
-                throw new IllegalArgumentException(packageName + " is not a valid package", e);
+                throw new IllegalArgumentException(componentName + " is not a valid package", e);
             }
 
             synchronized (mLock) {
                 final AutofillManagerServiceImpl service = getServiceForUserLocked(userId);
                 return service.startSessionLocked(activityToken, getCallingUid(), appCallback,
-                        autofillId, bounds, value, hasCallback, flags, packageName);
+                        autofillId, bounds, value, hasCallback, flags, componentName);
             }
         }
 
@@ -603,7 +604,8 @@
         @Override
         public int updateOrRestartSession(IBinder activityToken, IBinder appCallback,
                 AutofillId autoFillId, Rect bounds, AutofillValue value, int userId,
-                boolean hasCallback, int flags, String packageName, int sessionId, int action) {
+                boolean hasCallback, int flags, ComponentName componentName, int sessionId,
+                int action) {
             boolean restart = false;
             synchronized (mLock) {
                 final AutofillManagerServiceImpl service = peekServiceForUserLocked(userId);
@@ -614,7 +616,7 @@
             }
             if (restart) {
                 return startSession(activityToken, appCallback, autoFillId, bounds, value, userId,
-                        hasCallback, flags, packageName);
+                        hasCallback, flags, componentName);
             }
 
             // Nothing changed...
diff --git a/services/autofill/java/com/android/server/autofill/AutofillManagerServiceImpl.java b/services/autofill/java/com/android/server/autofill/AutofillManagerServiceImpl.java
index 3a3b570..a17c3ca 100644
--- a/services/autofill/java/com/android/server/autofill/AutofillManagerServiceImpl.java
+++ b/services/autofill/java/com/android/server/autofill/AutofillManagerServiceImpl.java
@@ -32,6 +32,7 @@
 import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.pm.ServiceInfo;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
@@ -43,6 +44,7 @@
 import android.os.Looper;
 import android.os.RemoteCallbackList;
 import android.os.RemoteException;
+import android.os.UserHandle;
 import android.os.UserManager;
 import android.provider.Settings;
 import android.service.autofill.AutofillService;
@@ -279,7 +281,7 @@
     int startSessionLocked(@NonNull IBinder activityToken, int uid,
             @NonNull IBinder appCallbackToken, @NonNull AutofillId autofillId,
             @NonNull Rect virtualBounds, @Nullable AutofillValue value, boolean hasCallback,
-            int flags, @NonNull String packageName) {
+            int flags, @NonNull ComponentName componentName) {
         if (!isEnabled()) {
             return 0;
         }
@@ -289,7 +291,7 @@
         pruneAbandonedSessionsLocked();
 
         final Session newSession = createSessionByTokenLocked(activityToken, uid, appCallbackToken,
-                hasCallback, packageName);
+                hasCallback, componentName);
         if (newSession == null) {
             return NO_SESSION;
         }
@@ -386,7 +388,8 @@
     }
 
     private Session createSessionByTokenLocked(@NonNull IBinder activityToken, int uid,
-            @NonNull IBinder appCallbackToken, boolean hasCallback, @NonNull String packageName) {
+            @NonNull IBinder appCallbackToken, boolean hasCallback,
+            @NonNull ComponentName componentName) {
         // use random ids so that one app cannot know that another app creates sessions
         int sessionId;
         int tries = 0;
@@ -400,15 +403,44 @@
             sessionId = sRandom.nextInt();
         } while (sessionId == NO_SESSION || mSessions.indexOfKey(sessionId) >= 0);
 
+        assertCallerLocked(componentName);
+
         final Session newSession = new Session(this, mUi, mContext, mHandlerCaller, mUserId, mLock,
                 sessionId, uid, activityToken, appCallbackToken, hasCallback,
-                mUiLatencyHistory, mInfo.getServiceInfo().getComponentName(), packageName);
+                mUiLatencyHistory, mInfo.getServiceInfo().getComponentName(), componentName);
         mSessions.put(newSession.id, newSession);
 
         return newSession;
     }
 
     /**
+     * Asserts the component is owned by the caller.
+     */
+    private void assertCallerLocked(@NonNull ComponentName componentName) {
+        final PackageManager pm = mContext.getPackageManager();
+        final int callingUid = Binder.getCallingUid();
+        final int packageUid;
+        try {
+            packageUid = pm.getPackageUidAsUser(componentName.getPackageName(),
+                    UserHandle.getCallingUserId());
+        } catch (NameNotFoundException e) {
+            throw new SecurityException("Could not verify UID for " + componentName);
+        }
+        if (callingUid != packageUid) {
+            final String[] packages = pm.getPackagesForUid(callingUid);
+            final String callingPackage = packages != null ? packages[0] : "uid-" + callingUid;
+            Slog.w(TAG, "App (package=" + callingPackage + ", UID=" + callingUid
+                    + ") passed component (" + componentName + ") owned by UID " + packageUid);
+            mMetricsLogger.write(new LogMaker(MetricsEvent.AUTOFILL_FORGED_COMPONENT_ATTEMPT)
+                    .setPackageName(callingPackage)
+                    .addTaggedData(MetricsEvent.FIELD_AUTOFILL_SERVICE, getServicePackageName())
+                    .addTaggedData(MetricsEvent.FIELD_AUTOFILL_FORGED_COMPONENT_NAME,
+                            componentName == null ? "null" : componentName.flattenToShortString()));
+            throw new SecurityException("Invalid component: " + componentName);
+        }
+    }
+
+    /**
      * Restores a session after an activity was temporarily destroyed.
      *
      * @param sessionId The id of the session to restore
diff --git a/services/autofill/java/com/android/server/autofill/Session.java b/services/autofill/java/com/android/server/autofill/Session.java
index 905db67..c5cf970 100644
--- a/services/autofill/java/com/android/server/autofill/Session.java
+++ b/services/autofill/java/com/android/server/autofill/Session.java
@@ -126,8 +126,8 @@
     @GuardedBy("mLock")
     @NonNull private IBinder mActivityToken;
 
-    /** Package name of the app that is auto-filled */
-    @NonNull private final String mPackageName;
+    /** Component that's being auto-filled */
+    @NonNull private final ComponentName mComponentName;
 
     @GuardedBy("mLock")
     private final ArrayMap<AutofillId, ViewState> mViewStates = new ArrayMap<>();
@@ -227,6 +227,16 @@
                 structure.ensureData();
 
                 // Sanitize structure before it's sent to service.
+                final ComponentName componentNameFromApp = structure.getActivityComponent();
+                if (!mComponentName.equals(componentNameFromApp)) {
+                    Slog.w(TAG, "Activity " + mComponentName + " forged different component on "
+                            + "AssistStructure: " + componentNameFromApp);
+                    structure.setActivityComponent(mComponentName);
+                    mMetricsLogger.write(newLogMaker(MetricsEvent.AUTOFILL_FORGED_COMPONENT_ATTEMPT)
+                            .addTaggedData(MetricsEvent.FIELD_AUTOFILL_FORGED_COMPONENT_NAME,
+                                            componentNameFromApp == null ? "null"
+                                                    : componentNameFromApp.flattenToShortString()));
+                }
                 structure.sanitizeForParceling(true);
 
                 // Flags used to start the session.
@@ -415,7 +425,7 @@
             @NonNull Context context, @NonNull HandlerCaller handlerCaller, int userId,
             @NonNull Object lock, int sessionId, int uid, @NonNull IBinder activityToken,
             @NonNull IBinder client, boolean hasCallback, @NonNull LocalLog uiLatencyHistory,
-            @NonNull ComponentName componentName, @NonNull String packageName) {
+            @NonNull ComponentName serviceComponentName, @NonNull ComponentName appComponentName) {
         id = sessionId;
         this.uid = uid;
         mStartTime = SystemClock.elapsedRealtime();
@@ -423,11 +433,11 @@
         mLock = lock;
         mUi = ui;
         mHandlerCaller = handlerCaller;
-        mRemoteFillService = new RemoteFillService(context, componentName, userId, this);
+        mRemoteFillService = new RemoteFillService(context, serviceComponentName, userId, this);
         mActivityToken = activityToken;
         mHasCallback = hasCallback;
         mUiLatencyHistory = uiLatencyHistory;
-        mPackageName = packageName;
+        mComponentName = appComponentName;
         mClient = IAutoFillManagerClient.Stub.asInterface(client);
 
         writeLog(MetricsEvent.AUTOFILL_SESSION_STARTED);
@@ -1008,8 +1018,8 @@
                 final IAutoFillManagerClient client = getClient();
                 mPendingSaveUi = new PendingUi(mActivityToken, id, client);
                 getUiForShowing().showSaveUi(mService.getServiceLabel(), mService.getServiceIcon(),
-                        mService.getServicePackageName(), saveInfo, valueFinder, mPackageName, this,
-                        mPendingSaveUi);
+                        mService.getServicePackageName(), saveInfo, valueFinder,
+                        mComponentName.getPackageName(), this, mPendingSaveUi);
                 if (client != null) {
                     try {
                         client.setSaveUiState(id, true);
@@ -1365,7 +1375,7 @@
         }
 
         getUiForShowing().showFillUi(filledId, response, filterText,
-                mService.getServicePackageName(), mPackageName, this);
+                mService.getServicePackageName(), mComponentName.getPackageName(), this);
 
         synchronized (mLock) {
             if (mUiShownTime == 0) {
@@ -1690,14 +1700,14 @@
 
     @Override
     public String toString() {
-        return "Session: [id=" + id + ", pkg=" + mPackageName + "]";
+        return "Session: [id=" + id + ", pkg=" + mComponentName.getPackageName() + "]";
     }
 
     void dumpLocked(String prefix, PrintWriter pw) {
         final String prefix2 = prefix + "  ";
         pw.print(prefix); pw.print("id: "); pw.println(id);
         pw.print(prefix); pw.print("uid: "); pw.println(uid);
-        pw.print(prefix); pw.print("mPackagename: "); pw.println(mPackageName);
+        pw.print(prefix); pw.print("mComponentName: "); pw.println(mComponentName);
         pw.print(prefix); pw.print("mActivityToken: "); pw.println(mActivityToken);
         pw.print(prefix); pw.print("mStartTime: "); pw.println(mStartTime);
         pw.print(prefix); pw.print("Time to show UI: ");
@@ -1920,7 +1930,7 @@
     }
 
     private LogMaker newLogMaker(int category, String servicePackageName) {
-        return Helper.newLogMaker(category, mPackageName, servicePackageName);
+        return Helper.newLogMaker(category, mComponentName.getPackageName(), servicePackageName);
     }
 
     private void writeLog(int category) {