platform_system_sepolicy/public/update_engine_common.te
Nick Kralevich 50bb7b5a67 Label /proc/misc
Label /proc/misc and allow access to untrusted_apps targeting older API
versions, as well as update_engine_common.

/proc/misc is used by some banking apps to try to detect if they are
running in an emulated environment.

TODO: Remove access to proc:file from update_engine_common after more
testing.

Bug: 35917228
Test: Device boots and no new denials.
Change-Id: If1b97a9c55a74cb74d1bb15137201ffb95b5bd75
2017-03-03 12:20:38 -08:00

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1.9 KiB
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# update_engine payload application permissions. These are shared between the
# background daemon and the recovery tool to sideload an update.
# Allow update_engine to reach block devices in /dev/block.
allow update_engine_common block_device:dir search;
# Allow read/write on system and boot partitions.
allow update_engine_common boot_block_device:blk_file rw_file_perms;
allow update_engine_common system_block_device:blk_file rw_file_perms;
# Allow to set recovery options in the BCB. Used to trigger factory reset when
# the update to an older version (channel change) or incompatible version
# requires it.
allow update_engine_common misc_block_device:blk_file rw_file_perms;
# Allow update_engine_common to mount on the /postinstall directory and reset the
# labels on the mounted filesystem to postinstall_file.
allow update_engine_common postinstall_mnt_dir:dir mounton;
allow update_engine_common postinstall_file:filesystem { mount unmount relabelfrom relabelto };
allow update_engine_common labeledfs:filesystem relabelfrom;
# Allow update_engine_common to read and execute postinstall_file.
allow update_engine_common postinstall_file:file rx_file_perms;
allow update_engine_common postinstall_file:lnk_file r_file_perms;
allow update_engine_common postinstall_file:dir r_dir_perms;
# A postinstall program is typically a shell script (with a #!), so we allow
# to execute those.
allow update_engine_common shell_exec:file rx_file_perms;
# Allow update_engine_common to suspend, resume and kill the postinstall program.
allow update_engine_common postinstall:process { signal sigstop };
# access /proc/misc
# Access is also granted to proc:file, but it is likely unneeded
# due to the more specific grant to proc_misc immediately below.
allow update_engine proc:file r_file_perms; # delete candidate
allow update_engine proc_misc:file r_file_perms;
# read directories on /system and /vendor
allow update_engine system_file:dir r_dir_perms;