tequilaOS/platform_system_core
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Move creation of /data/user/0 and /data/media/obb to vold

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To prevent bugs, directory creation and encryption should happen
together.  /data/user/0 (and its "alias" /data/data) is a per-user
encrypted directory; such directories can only be encrypted by vold.
Therefore, move its creation to vold as well.

Besides closing the uncomfortably-large gap between the creation and
encryption of /data/user/0, this allows removing init's write access to
/data/user and similar directories (SELinux type system_userdir_file) to
prevent any such issues from being reintroduced in the future.

To also allow removing init's write access to /data/media (SELinux type
media_userdir_file), which also contains per-user encrypted directories,
also move the creation and encryption of /data/media/obb to vold.

Bug: 156305599
BYPASS_INCLUSIVE_LANGUAGE_REASON=Linux API ("slave" mount flag)
Change-Id: I7245251eeb56b345b6c7711482c0aa5848648edb
This commit is contained in:
Eric Biggers 2022-05-11 05:33:21 +00:00
parent abff801ae6
commit ef9275223c
2 changed files with 4 additions and 18 deletions
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6
init/util.cpp
View file

@ -465,12 +465,6 @@ static FscryptAction FscryptInferAction(const std::string& dir) {
return FscryptAction::kNone;
}
// Special-case /data/media/obb per b/64566063
if (dir == "/data/media/obb") {
// Try to set policy on this directory, but if it is non-empty this may fail.
return FscryptAction::kAttempt;
}
// Only set policy on first level /data directories
// To make this less restrictive, consider using a policy file.
// However this is overkill for as long as the policy is simply

16
rootdir/init.rc
View file

@ -840,7 +840,6 @@ on post-fs-data
# Do not place files or directories in /data/local/tmp
mkdir /data/local/tmp 0771 shell shell
mkdir /data/local/traces 0777 shell shell
mkdir /data/data 0771 system system encryption=None
mkdir /data/app-private 0771 system system encryption=Require
mkdir /data/app-ephemeral 0771 system system encryption=Require
mkdir /data/app-asec 0700 root root encryption=Require
@ -915,13 +914,6 @@ on post-fs-data
mkdir /data/user 0711 system system encryption=None
mkdir /data/user_de 0711 system system encryption=None
# Unlink /data/user/0 if we previously symlink it to /data/data
rm /data/user/0
# Bind mount /data/user/0 to /data/data
mkdir /data/user/0 0700 system system encryption=None
mount none /data/data /data/user/0 bind rec
# A tmpfs directory, which will contain all apps CE DE data directory that
# bind mount from the original source.
mount tmpfs tmpfs /data_mirror nodev noexec nosuid mode=0700,uid=0,gid=1000
@ -933,8 +925,10 @@ on post-fs-data
mkdir /data_mirror/data_ce/null 0700 root root
mkdir /data_mirror/data_de/null 0700 root root
# Bind mount CE and DE data directory to mirror's default volume directory
mount none /data/user /data_mirror/data_ce/null bind rec
# Bind mount CE and DE data directory to mirror's default volume directory.
# The 'slave' option (MS_SLAVE) is needed to cause the later bind mount of
# /data/data onto /data/user/0 to propagate to /data_mirror/data_ce/null/0.
mount none /data/user /data_mirror/data_ce/null bind rec slave
mount none /data/user_de /data_mirror/data_de/null bind rec
# Create mirror directory for jit profiles
@ -967,10 +961,8 @@ on post-fs-data
wait_for_prop apexd.status activated
perform_apex_config
# Special-case /data/media/obb per b/64566063
mkdir /data/media 0770 media_rw media_rw encryption=None
exec - media_rw media_rw -- /system/bin/chattr +F /data/media
mkdir /data/media/obb 0770 media_rw media_rw encryption=Attempt
# Create directories for boot animation.
mkdir /data/bootanim 0755 system system encryption=None