Enforce ComponentName belongs to caller app

Add checks that enforce ComponentName's package belongs to calling app
in MediaButtonReceiverHolder and MediaSessionRecord. This avoids
privileged execution of arbitrary code.

Bug: 238177121
Test: atest CtsMediaBetterTogetherTestCases
Change-Id: Iac143d8bbc9422f3ca3f42f8c0154b9906ecd897
Merged-In: Iac143d8bbc9422f3ca3f42f8c0154b9906ecd897

services/core/java/com/android/server/media/MediaButtonReceiverHolder.java

@@ -32,6 +32,7 @@ import android.os.Handler;
 import android.os.PowerWhitelistManager;
 import android.os.UserHandle;
 import android.text.TextUtils;
+import android.util.EventLog;
 import android.util.Log;
 import android.view.KeyEvent;
 
@@ -117,6 +118,12 @@ final class MediaButtonReceiverHolder {
         int componentType = getComponentType(pendingIntent);
         ComponentName componentName = getComponentName(pendingIntent, componentType);
         if (componentName != null) {
+            if (!TextUtils.equals(componentName.getPackageName(), sessionPackageName)) {
+                EventLog.writeEvent(0x534e4554, "238177121", -1, ""); // SafetyNet logging
+                throw new IllegalArgumentException("ComponentName does not belong to "
+                        + "sessionPackageName. sessionPackageName = " + sessionPackageName
+                        + ", ComponentName pkg = " + componentName.getPackageName());
+            }
             return new MediaButtonReceiverHolder(userId, pendingIntent, componentName,
                     componentType);
         }

services/core/java/com/android/server/media/MediaSessionRecord.java

@@ -53,6 +53,7 @@ import android.os.RemoteException;
 import android.os.ResultReceiver;
 import android.os.SystemClock;
 import android.text.TextUtils;
+import android.util.EventLog;
 import android.util.Log;
 import android.view.KeyEvent;
 
@@ -934,6 +935,14 @@ public class MediaSessionRecord implements IBinder.DeathRecipient, MediaSessionR
         @Override
         public void setMediaButtonReceiver(PendingIntent pi, String sessionPackageName)
                 throws RemoteException {
+            //mPackageName has been verified in MediaSessionService.enforcePackageName().
+            if (!TextUtils.equals(sessionPackageName, mPackageName)) {
+                EventLog.writeEvent(0x534e4554, "238177121", -1, ""); // SafetyNet logging
+                throw new IllegalArgumentException("sessionPackageName name does not match "
+                        + "package name provided to MediaSessionRecord. sessionPackageName = "
+                        + sessionPackageName + ", pkg = "
+                        + mPackageName);
+            }
             final long token = Binder.clearCallingIdentity();
             try {
                 if ((mPolicies & MediaSessionPolicyProvider.SESSION_POLICY_IGNORE_BUTTON_RECEIVER)
@@ -952,6 +961,15 @@ public class MediaSessionRecord implements IBinder.DeathRecipient, MediaSessionR
         public void setMediaButtonBroadcastReceiver(ComponentName receiver) throws RemoteException {
             final long token = Binder.clearCallingIdentity();
             try {
+                //mPackageName has been verified in MediaSessionService.enforcePackageName().
+                if (receiver != null && !TextUtils.equals(
+                        mPackageName, receiver.getPackageName())) {
+                    EventLog.writeEvent(0x534e4554, "238177121", -1, ""); // SafetyNet logging
+                    throw new IllegalArgumentException("receiver does not belong to "
+                            + "package name provided to MediaSessionRecord. Pkg = " + mPackageName
+                            + ", Receiver Pkg = " + receiver.getPackageName());
+                }
+
                 if ((mPolicies & MediaSessionPolicyProvider.SESSION_POLICY_IGNORE_BUTTON_RECEIVER)
                         != 0) {
                     return;