Grant vold, installd, zygote and apps access to /mnt/pass_through
/mnt/pass_through was introduced to allow the FUSE daemon unrestricted
access to the lower filesystem (or sdcardfs).
At zygote fork time, the FUSE daemon will have /mnt/pass_through/0
bind mounted to /storage instead of /mnt/user/0. To keep /sdcard
(symlink to /storage/self/primary) paths working, we create a
'self' directory with an additional 'primary' symlink to
/mnt/pass_through/0/emulated/0 which is a FUSE mount point.
The following components need varying sepolicy privileges:
Vold: Creates the self/primary symlink and mounts the lower filesystem
on /mnt/pass_through/0/emulated. So needs create_dir and mount access
+ create_file access for the symlink
zygote: In case zygote starts an app before vold sets up the paths.
This is unlikely but can happen if the FUSE daemon (a zygote forked app)
is started before system_server completes vold mounts.
Same sepolicy requirements as vold
installd: Needs to clear/destroy app data using lower filesystem
mounted on /mnt/pass_through so needs read_dir access to walk
/mnt/pass_through
priv_app (FUSE daemon): Needs to server content from the lower
filesystem mounted on /mnt/pass_through so needs read_dir access to
walk /mnt/pass_through
Bug: 135341433
Test: adb shell ls /mnt/pass_through/0/self/primary
Change-Id: I16e35b9007c2143282600c56adbc9468a1b7f240
diff --git a/private/file_contexts b/private/file_contexts
index 2ab86fd..aa4ec5e 100644
--- a/private/file_contexts
+++ b/private/file_contexts
@@ -690,6 +690,7 @@
# external storage
/mnt/media_rw(/.*)? u:object_r:mnt_media_rw_file:s0
/mnt/user(/.*)? u:object_r:mnt_user_file:s0
+/mnt/pass_through(/.*)? u:object_r:mnt_pass_through_file:s0
/mnt/sdcard u:object_r:mnt_sdcard_file:s0
/mnt/runtime(/.*)? u:object_r:storage_file:s0
/storage(/.*)? u:object_r:storage_file:s0