From 012f0762275df7125358e8db352834af60495b43 Mon Sep 17 00:00:00 2001 From: Jeff Sharkey Date: Mon, 31 Oct 2016 14:33:49 -0600 Subject: Public volumes belong to a single user. When a public (vfat) device is inserted, it's strongly associated with the current foreground user, and no other users should be able to access it, since otherwise that would be a cross-user data leak. To use the device under a different user, switch users and then eject/remount the device. Test: verified user isolation of USB drive Bug: 32523490 Change-Id: I590c791996f1fea8d78f625dc942d149f1f41614 (cherry picked from commit 8b38d083c42e2706e1ff5a1410fa61d1f5dea3f5) (cherry picked from commit 47e62b7fe6807a274ba760a8fecfd624fe792da9) --- .../src/com/android/externalstorage/ExternalStorageProvider.java | 3 ++- services/core/java/com/android/server/MountService.java | 9 ++++++++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java index 46b73d8..f72832a 100644 --- a/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java +++ b/packages/ExternalStorageProvider/src/com/android/externalstorage/ExternalStorageProvider.java @@ -135,7 +135,8 @@ public class ExternalStorageProvider extends DocumentsProvider { final VolumeInfo privateVol = mStorageManager.findPrivateForEmulated(volume); title = mStorageManager.getBestVolumeDescription(privateVol); } - } else if (volume.getType() == VolumeInfo.TYPE_PUBLIC) { + } else if (volume.getType() == VolumeInfo.TYPE_PUBLIC + && volume.getMountUserId() == userId) { rootId = volume.getFsUuid(); title = mStorageManager.getBestVolumeDescription(volume); } else { diff --git a/services/core/java/com/android/server/MountService.java b/services/core/java/com/android/server/MountService.java index d539201..60d7428 100644 --- a/services/core/java/com/android/server/MountService.java +++ b/services/core/java/com/android/server/MountService.java @@ -169,6 +169,11 @@ class MountService extends IMountService.Stub } @Override + public void onSwitchUser(int userHandle) { + mMountService.mCurrentUserId = userHandle; + } + + @Override public void onStartUser(int userHandle) { mMountService.onStartUser(userHandle); } @@ -307,6 +312,8 @@ class MountService extends IMountService.Stub @GuardedBy("mLock") private String mMoveTargetUuid; + private volatile int mCurrentUserId = UserHandle.USER_OWNER; + private VolumeInfo findVolumeByIdOrThrow(String id) { synchronized (mLock) { final VolumeInfo vol = mVolumes.get(id); @@ -1193,7 +1200,7 @@ class MountService extends IMountService.Stub vol.mountFlags |= VolumeInfo.MOUNT_FLAG_VISIBLE; } - vol.mountUserId = UserHandle.USER_OWNER; + vol.mountUserId = mCurrentUserId; mHandler.obtainMessage(H_VOLUME_MOUNT, vol).sendToTarget(); } else if (vol.type == VolumeInfo.TYPE_PRIVATE) { -- cgit v1.1