RESTRICT AUTOMERGE Revoke SYSTEM_ALERT_WINDOW on upgrade past api 23

Bug: 221040577
Test: atest PermissionTest23#testPre23AppsWithSystemAlertWindowGetDeniedOnUpgrade
Change-Id: I4b4605aaae107875811070dea6d031c5d9f25c96
(cherry picked from commit 14551ab6d2c754d83d6b504549aabb40018d9c6a)
Merged-In: I4b4605aaae107875811070dea6d031c5d9f25c96

3 files changed, 57 insertions, 36 deletions

diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index 362a8cf03aaa..f546a3b04236 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -12522,9 +12522,7 @@ public class PackageManagerService extends IPackageManager.Stub
 
                 AsyncTask.execute(() -> {
                     if (hasOldPkg) {
-                        mPermissionManager.revokeRuntimePermissionsIfGroupChanged(pkg, oldPkg,
-                                allPackageNames);
-                        mPermissionManager.revokeStoragePermissionsIfScopeExpanded(pkg, oldPkg);
+                        mPermissionManager.onPackageUpdated(pkg, oldPkg, allPackageNames);
                     }
                     if (hasPermissionDefinitionChanges) {
                         mPermissionManager.revokeRuntimePermissionsIfPermissionDefinitionChanged(
diff --git a/services/core/java/com/android/server/pm/permission/PermissionManagerService.java b/services/core/java/com/android/server/pm/permission/PermissionManagerService.java
index 48f39267a59f..575208933658 100644
--- a/services/core/java/com/android/server/pm/permission/PermissionManagerService.java
+++ b/services/core/java/com/android/server/pm/permission/PermissionManagerService.java
@@ -2322,6 +2322,46 @@ public class PermissionManagerService extends IPermissionManager.Stub {
     }
 
     /**
+     * If the package was below api 23, got the SYSTEM_ALERT_WINDOW permission automatically, and
+     * then updated past api 23, and the app does not satisfy any of the other SAW permission flags,
+     * the permission should be revoked.
+     *
+     * @param newPackage The new package that was installed
+     * @param oldPackage The old package that was updated
+     */
+    private void revokeSystemAlertWindowIfUpgradedPast23(
+            @NonNull AndroidPackage newPackage,
+            @NonNull AndroidPackage oldPackage,
+            @NonNull PermissionCallback permissionCallback) {
+        if (oldPackage.getTargetSdkVersion() >= Build.VERSION_CODES.M
+                || newPackage.getTargetSdkVersion() < Build.VERSION_CODES.M
+                || !newPackage.getRequestedPermissions()
+                .contains(Manifest.permission.SYSTEM_ALERT_WINDOW)) {
+            return;
+        }
+
+        BasePermission saw;
+        synchronized (mLock) {
+            saw = mSettings.getPermissionLocked(Manifest.permission.SYSTEM_ALERT_WINDOW);
+        }
+        final PackageSetting ps = (PackageSetting)
+                mPackageManagerInt.getPackageSetting(newPackage.getPackageName());
+        if (grantSignaturePermission(Manifest.permission.SYSTEM_ALERT_WINDOW, newPackage, ps, saw,
+                ps.getPermissionsState())) {
+            return;
+        }
+        for (int userId : mUserManagerInt.getUserIds()) {
+            try {
+                revokePermissionFromPackageForUser(newPackage.getPackageName(),
+                        Manifest.permission.SYSTEM_ALERT_WINDOW, false, userId, permissionCallback);
+            } catch (IllegalStateException | SecurityException e) {
+                Log.e(TAG, "unable to revoke SYSTEM_ALERT_WINDOW for "
+                        + newPackage.getPackageName() + " user " + userId, e);
+            }
+        }
+    }
+
+    /**
      * We might auto-grant permissions if any permission of the group is already granted. Hence if
      * the group of a granted permission changes we need to revoke it to avoid having permissions of
      * the new group auto-granted.
@@ -4798,24 +4838,20 @@ public class PermissionManagerService extends IPermissionManager.Stub {
             return PermissionManagerService.this.isPermissionsReviewRequired(pkg, userId);
         }
         /**
-         * If the app is updated, and has scoped storage permissions, then it is possible that the
-         * app updated in an attempt to get unscoped storage. If so, revoke all storage permissions.
+         * If the app is updated, then some checks need to be performed to ensure the
+         * package is not attempting to expoit permission changes across API boundaries.
          * @param newPackage The new package that was installed
          * @param oldPackage The old package that was updated
+         * @param allPackageNames The current packages in the system
          */
-        public void revokeStoragePermissionsIfScopeExpanded(
-                @NonNull AndroidPackage newPackage,
-                @NonNull AndroidPackage oldPackage
-        ) {
-            PermissionManagerService.this.revokeStoragePermissionsIfScopeExpanded(newPackage,
-                    oldPackage, mDefaultPermissionCallback);
-        }
-
-        @Override
-        public void revokeRuntimePermissionsIfGroupChanged(
+        public void onPackageUpdated(
                 @NonNull AndroidPackage newPackage,
                 @NonNull AndroidPackage oldPackage,
                 @NonNull ArrayList<String> allPackageNames) {
+            PermissionManagerService.this.revokeStoragePermissionsIfScopeExpanded(newPackage,
+                    oldPackage, mDefaultPermissionCallback);
+            PermissionManagerService.this.revokeSystemAlertWindowIfUpgradedPast23(newPackage,
+                    oldPackage, mDefaultPermissionCallback);
             PermissionManagerService.this.revokeRuntimePermissionsIfGroupChanged(newPackage,
                     oldPackage, allPackageNames, mDefaultPermissionCallback);
         }
diff --git a/services/core/java/com/android/server/pm/permission/PermissionManagerServiceInternal.java b/services/core/java/com/android/server/pm/permission/PermissionManagerServiceInternal.java
index df0edfa16924..7003c7a2027e 100644
--- a/services/core/java/com/android/server/pm/permission/PermissionManagerServiceInternal.java
+++ b/services/core/java/com/android/server/pm/permission/PermissionManagerServiceInternal.java
@@ -239,16 +239,14 @@ public abstract class PermissionManagerServiceInternal extends PermissionManager
     public abstract void resetRuntimePermissions(@NonNull AndroidPackage pkg,
             @UserIdInt int userId);
 
-    /**
-     * We might auto-grant permissions if any permission of the group is already granted. Hence if
-     * the group of a granted permission changes we need to revoke it to avoid having permissions of
-     * the new group auto-granted.
-     *
-     * @param newPackage The new package that was installed
-     * @param oldPackage The old package that was updated
-     * @param allPackageNames All packages
-     */
-    public abstract void revokeRuntimePermissionsIfGroupChanged(
+     /**
+      * If the app is updated, then some checks need to be performed to ensure the package is not 
+      * attempting to expoit permission changes across API boundaries.
+      * @param newPackage The new package that was installed
+      * @param oldPackage The old package that was updated
+      * @param allPackageNames The current packages in the system
+      */
+    public abstract void onPackageUpdated(
             @NonNull AndroidPackage newPackage,
             @NonNull AndroidPackage oldPackage,
             @NonNull ArrayList<String> allPackageNames);
@@ -266,17 +264,6 @@ public abstract class PermissionManagerServiceInternal extends PermissionManager
             @NonNull ArrayList<String> allPackageNames);
 
     /**
-     * If the app is updated, and has scoped storage permissions, then it is possible that the
-     * app updated in an attempt to get unscoped storage. If so, revoke all storage permissions.
-     * @param newPackage The new package that was installed
-     * @param oldPackage The old package that was updated
-     */
-    public abstract void revokeStoragePermissionsIfScopeExpanded(
-            @NonNull AndroidPackage newPackage,
-            @NonNull AndroidPackage oldPackage
-    );
-
-    /**
      * Add all permissions in the given package.
      * <p>
      * NOTE: argument {@code groupTEMP} is temporary until mPermissionGroups is moved to