Merge tag 'android-security-13.0.0_r19' into staging/lineage-20.0_android-security-13.0.0_r19

Android security 13.0.0 release 19

* tag 'android-security-13.0.0_r19':
  Verify UID of incoming Zygote connections.
  Fix security vulnerability of non-dynamic permission removal
  Fix security vulnerability allowing apps to start from background
  [PM] Send ACTION_PACKAGE_CHANGED when mimeGroups are changed

Change-Id: I73827bcd4350ecf7c70be1f439ea7758827b8b25
diff --git a/core/java/com/android/internal/os/ZygoteConnection.java b/core/java/com/android/internal/os/ZygoteConnection.java
index 993e4e7..765901a 100644
--- a/core/java/com/android/internal/os/ZygoteConnection.java
+++ b/core/java/com/android/internal/os/ZygoteConnection.java
@@ -93,6 +93,9 @@
             throw ex;
         }
 
+        if (peer.getUid() != Process.SYSTEM_UID) {
+            throw new ZygoteSecurityException("Only system UID is allowed to connect to Zygote.");
+        }
         isEof = false;
     }
 
diff --git a/core/jni/com_android_internal_os_ZygoteCommandBuffer.cpp b/core/jni/com_android_internal_os_ZygoteCommandBuffer.cpp
index add645d..b48fe41 100644
--- a/core/jni/com_android_internal_os_ZygoteCommandBuffer.cpp
+++ b/core/jni/com_android_internal_os_ZygoteCommandBuffer.cpp
@@ -353,6 +353,18 @@
   return result;
 }
 
+static uid_t getSocketPeerUid(int socket, const std::function<void(const std::string&)>& fail_fn) {
+  struct ucred credentials;
+  socklen_t cred_size = sizeof credentials;
+  if (getsockopt(socket, SOL_SOCKET, SO_PEERCRED, &credentials, &cred_size) == -1
+      || cred_size != sizeof credentials) {
+    fail_fn(CREATE_ERROR("Failed to get socket credentials, %s",
+                         strerror(errno)));
+  }
+
+  return credentials.uid;
+}
+
 // Read all lines from the current command into the buffer, and then reset the buffer, so
 // we will start reading again at the beginning of the command, starting with the argument
 // count. And we don't need access to the fd to do so.
@@ -411,19 +423,12 @@
     fail_fn_z("Failed to retrieve session socket timeout");
   }
 
-  struct ucred credentials;
-  socklen_t cred_size = sizeof credentials;
-  if (getsockopt(n_buffer->getFd(), SOL_SOCKET, SO_PEERCRED, &credentials, &cred_size) == -1
-      || cred_size != sizeof credentials) {
-    fail_fn_1(CREATE_ERROR("ForkRepeatedly failed to get initial credentials, %s",
-                           strerror(errno)));
+  uid_t peerUid = getSocketPeerUid(session_socket, fail_fn_1);
+  if (peerUid != static_cast<uid_t>(expected_uid)) {
+    return JNI_FALSE;
   }
-
   bool first_time = true;
   do {
-    if (credentials.uid != expected_uid) {
-      return JNI_FALSE;
-    }
     n_buffer->readAllLines(first_time ? fail_fn_1 : fail_fn_n);
     n_buffer->reset();
     int pid = zygote::forkApp(env, /* no pipe FDs */ -1, -1, session_socket_fds,
@@ -453,30 +458,56 @@
     // Clear buffer and get count from next command.
     n_buffer->clear();
     for (;;) {
+      bool valid_session_socket = true;
       // Poll isn't strictly necessary for now. But without it, disconnect is hard to detect.
       int poll_res = TEMP_FAILURE_RETRY(poll(fd_structs, 2, -1 /* infinite timeout */));
       if ((fd_structs[SESSION_IDX].revents & POLLIN) != 0) {
         if (n_buffer->getCount(fail_fn_z) != 0) {
           break;
-        }  // else disconnected;
+        } else {
+          // Session socket was disconnected
+          valid_session_socket = false;
+          close(session_socket);
+        }
       } else if (poll_res == 0 || (fd_structs[ZYGOTE_IDX].revents & POLLIN) == 0) {
         fail_fn_z(
             CREATE_ERROR("Poll returned with no descriptors ready! Poll returned %d", poll_res));
       }
-      // We've now seen either a disconnect or connect request.
-      close(session_socket);
-      int new_fd = TEMP_FAILURE_RETRY(accept(zygote_socket_fd, nullptr, nullptr));
+      int new_fd = -1;
+      do {
+        // We've now seen either a disconnect or connect request.
+        new_fd = TEMP_FAILURE_RETRY(accept(zygote_socket_fd, nullptr, nullptr));
+        if (new_fd == -1) {
+          fail_fn_z(CREATE_ERROR("Accept(%d) failed: %s", zygote_socket_fd, strerror(errno)));
+        }
+        uid_t newPeerUid = getSocketPeerUid(new_fd, fail_fn_1);
+        if (newPeerUid != static_cast<uid_t>(expected_uid)) {
+          ALOGW("Dropping new connection with a mismatched uid %d\n", newPeerUid);
+          close(new_fd);
+          new_fd = -1;
+        } else {
+          // If we still have a valid session socket, close it now
+          if (valid_session_socket) {
+              close(session_socket);
+          }
+          valid_session_socket = true;
+        }
+      } while (!valid_session_socket);
+
+      // At this point we either have a valid new connection (new_fd > 0), or
+      // an existing session socket we can poll on
       if (new_fd == -1) {
-        fail_fn_z(CREATE_ERROR("Accept(%d) failed: %s", zygote_socket_fd, strerror(errno)));
+        // The new connection wasn't valid, and we still have an old one; retry polling
+        continue;
       }
       if (new_fd != session_socket) {
-          // Move new_fd back to the old value, so that we don't have to change Java-level data
-          // structures to reflect a change. This implicitly closes the old one.
-          if (TEMP_FAILURE_RETRY(dup2(new_fd, session_socket)) != session_socket) {
-            fail_fn_z(CREATE_ERROR("Failed to move fd %d to %d: %s",
-                                   new_fd, session_socket, strerror(errno)));
-          }
-          close(new_fd);  //  On Linux, fd is closed even if EINTR is returned.
+        // Move new_fd back to the old value, so that we don't have to change Java-level data
+        // structures to reflect a change. This implicitly closes the old one.
+        if (TEMP_FAILURE_RETRY(dup2(new_fd, session_socket)) != session_socket) {
+          fail_fn_z(CREATE_ERROR("Failed to move fd %d to %d: %s",
+                                 new_fd, session_socket, strerror(errno)));
+        }
+        close(new_fd);  //  On Linux, fd is closed even if EINTR is returned.
       }
       // If we ever return, we effectively reuse the old Java ZygoteConnection.
       // None of its state needs to change.
@@ -488,13 +519,6 @@
         fail_fn_z(CREATE_ERROR("Failed to set send timeout for socket %d: %s",
                                session_socket, strerror(errno)));
       }
-      if (getsockopt(session_socket, SOL_SOCKET, SO_PEERCRED, &credentials, &cred_size) == -1) {
-        fail_fn_z(CREATE_ERROR("ForkMany failed to get credentials: %s", strerror(errno)));
-      }
-      if (cred_size != sizeof credentials) {
-        fail_fn_z(CREATE_ERROR("ForkMany credential size = %d, should be %d",
-                               cred_size, static_cast<int>(sizeof credentials)));
-      }
     }
     first_time = false;
   } while (n_buffer->isSimpleForkCommand(minUid, fail_fn_n));
diff --git a/media/java/android/media/session/ParcelableListBinder.java b/media/java/android/media/session/ParcelableListBinder.java
index bbf1e08..d788284 100644
--- a/media/java/android/media/session/ParcelableListBinder.java
+++ b/media/java/android/media/session/ParcelableListBinder.java
@@ -45,6 +45,7 @@
     private static final int END_OF_PARCEL = 0;
     private static final int ITEM_CONTINUED = 1;
 
+    private final Class<T> mListElementsClass;
     private final Consumer<List<T>> mConsumer;
 
     private final Object mLock = new Object();
@@ -61,9 +62,11 @@
     /**
      * Creates an instance.
      *
+     * @param listElementsClass the class of the list elements.
      * @param consumer a consumer that consumes the list received
      */
-    public ParcelableListBinder(@NonNull Consumer<List<T>> consumer) {
+    public ParcelableListBinder(Class<T> listElementsClass, @NonNull Consumer<List<T>> consumer) {
+        mListElementsClass = listElementsClass;
         mConsumer = consumer;
     }
 
@@ -83,7 +86,13 @@
                 mCount = data.readInt();
             }
             while (i < mCount && data.readInt() != END_OF_PARCEL) {
-                mList.add(data.readParcelable(null));
+                Object object = data.readParcelable(null);
+                if (mListElementsClass.isAssignableFrom(object.getClass())) {
+                    // Checking list items are of compaitible types to validate against malicious
+                    // apps calling it directly via reflection with non compilable items.
+                    // See b/317048338 for more details
+                    mList.add((T) object);
+                }
                 i++;
             }
             if (i >= mCount) {
diff --git a/services/core/java/com/android/server/media/MediaSessionRecord.java b/services/core/java/com/android/server/media/MediaSessionRecord.java
index b459cfe..8f07b39 100644
--- a/services/core/java/com/android/server/media/MediaSessionRecord.java
+++ b/services/core/java/com/android/server/media/MediaSessionRecord.java
@@ -1100,12 +1100,14 @@
 
         @Override
         public IBinder getBinderForSetQueue() throws RemoteException {
-            return new ParcelableListBinder<QueueItem>((list) -> {
-                synchronized (mLock) {
-                    mQueue = list;
-                }
-                mHandler.post(MessageHandler.MSG_UPDATE_QUEUE);
-            });
+            return new ParcelableListBinder<QueueItem>(
+                    QueueItem.class,
+                    (list) -> {
+                        synchronized (mLock) {
+                            mQueue = list;
+                        }
+                        mHandler.post(MessageHandler.MSG_UPDATE_QUEUE);
+                    });
         }
 
         @Override
diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index 35be1bf..8c51df9 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -5913,9 +5913,26 @@
                 packageStateWrite.setMimeGroup(mimeGroup, mimeTypesSet);
             });
             if (mComponentResolver.updateMimeGroup(snapshotComputer(), packageName, mimeGroup)) {
-                Binder.withCleanCallingIdentity(() ->
-                        mPreferredActivityHelper.clearPackagePreferredActivities(packageName,
-                                UserHandle.USER_ALL));
+                Binder.withCleanCallingIdentity(() -> {
+                    mPreferredActivityHelper.clearPackagePreferredActivities(packageName,
+                            UserHandle.USER_ALL);
+                    // Send the ACTION_PACKAGE_CHANGED when the mimeGroup has changes
+                    final Computer snapShot = snapshotComputer();
+                    final ArrayList<String> components = new ArrayList<>(
+                            Collections.singletonList(packageName));
+                    final int appId = packageState.getAppId();
+                    final int[] userIds = resolveUserIds(UserHandle.USER_ALL);
+                    final String reason = "The mimeGroup is changed";
+                    for (int i = 0; i < userIds.length; i++) {
+                        final PackageUserStateInternal pkgUserState =
+                                packageState.getUserStates().get(userIds[i]);
+                        if (pkgUserState != null && pkgUserState.isInstalled()) {
+                            final int packageUid = UserHandle.getUid(userIds[i], appId);
+                            sendPackageChangedBroadcast(snapShot, packageName,
+                                    true /* dontKillApp */, components, packageUid, reason);
+                        }
+                    }
+                });
             }
 
             scheduleWriteSettings();
diff --git a/services/core/java/com/android/server/pm/permission/PermissionManagerServiceImpl.java b/services/core/java/com/android/server/pm/permission/PermissionManagerServiceImpl.java
index 96c34db..9c406c3 100644
--- a/services/core/java/com/android/server/pm/permission/PermissionManagerServiceImpl.java
+++ b/services/core/java/com/android/server/pm/permission/PermissionManagerServiceImpl.java
@@ -674,7 +674,7 @@
             if (bp == null) {
                 return;
             }
-            if (bp.isDynamic()) {
+            if (!bp.isDynamic()) {
                 // TODO: switch this back to SecurityException
                 Slog.wtf(TAG, "Not allowed to modify non-dynamic permission "
                         + permName);