From e3c537ddea5ce8b28eeb89300ef602753cfe42a4 Mon Sep 17 00:00:00 2001
From: Christophe Pinelli <cpinelli@google.com>
Date: Fri, 26 May 2023 22:33:09 +0000
Subject: [PATCH] Restrict activity launch when caller is running in the
 background

Test: atest BackgroundActivityLaunchTest#testBackgroundActivityBlockedInStartNextMatchingActivity
Bug: 230492947
Change-Id: Ie3bc5bd88bfd3bd4777210c0740ad34ea6d3311e
---
 .../server/wm/ActivityTaskManagerService.java | 52 +++++++++++--------
 1 file changed, 31 insertions(+), 21 deletions(-)

diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index 47b51ac164b95..4a658d6abaf41 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -1411,29 +1411,39 @@ public class ActivityTaskManagerService extends IActivityTaskManager.Stub {
 
             final long origId = Binder.clearCallingIdentity();
             // TODO(b/64750076): Check if calling pid should really be -1.
-            final int res = getActivityStartController()
-                    .obtainStarter(intent, "startNextMatchingActivity")
-                    .setCaller(r.app.getThread())
-                    .setResolvedType(r.resolvedType)
-                    .setActivityInfo(aInfo)
-                    .setResultTo(resultTo != null ? resultTo.token : null)
-                    .setResultWho(resultWho)
-                    .setRequestCode(requestCode)
-                    .setCallingPid(-1)
-                    .setCallingUid(r.launchedFromUid)
-                    .setCallingPackage(r.launchedFromPackage)
-                    .setCallingFeatureId(r.launchedFromFeatureId)
-                    .setRealCallingPid(-1)
-                    .setRealCallingUid(r.launchedFromUid)
-                    .setActivityOptions(options)
-                    .execute();
-            Binder.restoreCallingIdentity(origId);
+            try {
+                if (options == null) {
+                    options = new SafeActivityOptions(ActivityOptions.makeBasic());
+                }
 
-            r.finishing = wasFinishing;
-            if (res != ActivityManager.START_SUCCESS) {
-                return false;
+                // Fixes b/230492947
+                // Prevents background activity launch through #startNextMatchingActivity
+                // An activity going into the background could still go back to the foreground
+                // if the intent used matches both:
+                // - the activity in the background
+                // - a second activity.
+                options.getOptions(r).setAvoidMoveToFront();
+                final int res = getActivityStartController()
+                        .obtainStarter(intent, "startNextMatchingActivity")
+                        .setCaller(r.app.getThread())
+                        .setResolvedType(r.resolvedType)
+                        .setActivityInfo(aInfo)
+                        .setResultTo(resultTo != null ? resultTo.token : null)
+                        .setResultWho(resultWho)
+                        .setRequestCode(requestCode)
+                        .setCallingPid(-1)
+                        .setCallingUid(r.launchedFromUid)
+                        .setCallingPackage(r.launchedFromPackage)
+                        .setCallingFeatureId(r.launchedFromFeatureId)
+                        .setRealCallingPid(-1)
+                        .setRealCallingUid(r.launchedFromUid)
+                        .setActivityOptions(options)
+                        .execute();
+                r.finishing = wasFinishing;
+                return res == ActivityManager.START_SUCCESS;
+            } finally {
+                Binder.restoreCallingIdentity(origId);
             }
-            return true;
         }
     }