Of course, the cancer of Android, Huawei, has to do some f**king weird
modifications to the Linux kernel. Its kernel only accepts 1 single
policy load in its lifetime, a second load will result in ENOMEM error.
Since Huawei devices always use their own stupid ramdisk setup and not
system-as-root, not loading sepolicy is not a concern (for now).
Android Q init assumes rootfs to always be on EXT4 images, thus
never runs restorecon on the whole root directory. This is an issue
because some folders in rootfs were set with special selabels in
the system partition, but when copying over to initramfs by magiskinit,
these labels will not be preserved.
So the solution is to relabel the files in rootfs with the original
context right? Yes, but rootfs does not allow security xattr to be set
on files before the kernel SELinux initializes with genfs_contexts.
We have to load our sepolicy to the kernel before we clone the root
directory from system partition, which we will also restore the selabel
in the meantime.
Unfortunately this means that for each reboot, the exact same policy
will be loaded to the kernel twice: once in magiskinit so we can label
rootfs properly, and once by the original init, which is part of the
boot procedure. There is no easy way to prevent init from loading
sepolicy, as init will refuse to continue if policy loading has failed.
Allow zygote to execute other programs (such as dex2oat).
This fixes the bug that cause ART framework boot images failed to load
and result to extremely serious performance degradation.
Fix#1195
vector<bool> uses bitsets, so we actually only use 12k memory to
store all 3 possible PID info tables. PID checkup will be now become
O(1) instead of O(logn).
P.S. The reason why we don't use unordered_map is because including it
will result in significant binary size increase (might be due to the
complex hash table STL implementation? I really don't know).
MicroG uses a different package to handle DroidGuard service (SafetyNet),
but still uses the same com.google.android.gms.unstable process name.
Thanks to the changes in 4e53ebfe, we can target both official GMS
and MicroG SafetyNet services at the same time.
No matter if we use the old, buggy, error prone am_proc_start monitoring,
or the new APK inotify method, both methods rely on MagiskHide 'reacting'
fast enough to hijack the process before any detection has been done.
However, this is not reliable and practical. There are apps that utilize
native libraries to start detects and register SIGCONT signal handlers
to mitigate all existing MagiskHide process monitoring mechanism. So
our only solution is to hijack an app BEFORE it is started.
All Android apps' process is forked from zygote, so it is easily the
target to be monitored. All forks will be notified, and subsequent
thread spawning (Android apps are heaviliy multithreaded) from children
are also closely monitored to find the earliest possible point to
identify what the process will eventually be (before am_proc_bound).
ptrace is extremely complicated and very difficult to get right. The
current code is heaviliy tested on a stock Android 9.0 Pixel system,
so in theory it should work fine on most devices, but more tests and
potentially fixes are expected to follow this commit.
Shut down any UID matching process and resume if it turns out not to
be our target. Since we will record every single process we have ever
paused, this means that the same process will not be paused erroneously
for another time.
This is an optimization to hijack the app as soon as possible.
Before switching to the new MagiskHide implementation (APK inotify),
logcat parsing provides us lots of information to target a process.
We were targeting components so that apps with multi-processes
can still be hidden properly.
After switching to the new implementation, our granularity is limited
to the UID of the process. This is especially dangerous since Android
allow apps signed with the same signature to share UIDs, and many system
apps utilize this for elevated permissions for some services.
This commit introduces process name matching. We could not blanketly
target an UID, so the workaround is to verify its process name before
unmounting.
The tricky thing is that any app developer is allowed to name the
process of its component to whatever they want; there is no 'one
rule to catch them all' to target a specific package. As a result,
Magisk Manager is updated to scan through all components of all apps,
and show different processes of the same app, each as a separate
hide target in the list.
The hide target database also has to be updated accordingly.
Each hide target is now a <package name, process name> pair. The
magiskhide CLI and Magisk Manager is updated to support this new
target format.
Most Chinese devices (and supposedly Galaxy S10) running Android Pie
is using system-as-root without A/B partition.
https://source.android.com/devices/bootloader/system-as-root#about-system-as-root
According to the docs above, these devices will have a ramdisk block
with size 0 in their boot images. Since magiskinit can run independently
on system-as-root devices, we simply just create an empty ramdisk with
magiskinit added as init.
Huge thanks to @vvb2060 for the heads up and original PR.
Close#980, close#1102
Since we switched to imageless Magisk, module files are directly
stored in /data. However, /data is mounted with nosuid, which also
prevents SELinux typetransition to work (auto transition from one
domain to another when executing files with specific context).
This could cause serious issues when we are replacing system critical
components (e.g. app_process for Xposed), because most of them
are daemons that run in special process domains.
This commit introduced /data mirror. Using similar mirroring technique
we used for system and vendor, we mount another mirror that mounts
/data without nosuid flag. All module files are then mounted from this
mirror mountpoint instead of directly from /data.
Close#1080
Reinstalling system apps as data creates tons of issues.
Calling pm path <pkg> is extremely expensive and doesn't work in post-fs-data.
Parse through packages.xml to get APK path and UID at the same time.
As a bonus, we don't need to traverse /data/app for packages anymore.
Since we are parsing through /data/app/ to find target APKs for
monitoring, system apps will not be covered in this case.
Automatically reinstall system apps as if they received an update
and refresh the monitor target after it's done.
As a bonus, use RAII idioms for locking pthread_mutex_t.
- Fail fast on unsupported systems
- Show proper fail message on unsupported systems
- inotify_fd shall be swapped out before closing to prevent
the proc_monitor thread to read from incomplete inotify fd
- Directly get UID instead of traversing /data/data everytime
- Use /data/user_de/0 instead of /data/data on Android 7.0+
- Update hide_uid set incrementally when adding/initializing targets
- Guard hide_uid set with the same lock as hide_list vector
- Do not add GMS package into database; only add to in-memory list
With the new detection method, it is impossible to check for components.
Remove additional checks for components and simply hardcode string to
proc_monitor.cpp and query cmdline to see if it's GMS unstable.
This addresses wasted resources on applying custom namespace
on all GMS processes.
Signed-off-by: Park Ju Hyung <qkrwngud825@gmail.com>
Previous MagiskHide detects new app launches via listening through logcat
and filtering launch info messages.
This is extremely inefficient and prone to cause multiple issues both
theoratically and practically.
Rework this by using inotify to detect open() syscalls to target APKs.
This also solves issues related to Zygote-forked caching mechanisms such as
OnePlus OxygenOS' embryo.
Signed-off-by: Park Ju Hyung <qkrwngud825@gmail.com>
Mounting ext4 images causes tons of issues, such as unmountable with broken F2FS drivers.
Resizing is also very complicated and does not work properly on all devices.
Each step in either measuring free space, resizing, and shrinking the image is a
point of failure, and either step's failure could cause the module system completely broken.
The new method is to directly store modules into /data/adb/modules, and for module installation
on boot /data/adb/modules_update. Several compatibility layers has been done: the new path is
bind mounted to the old path (/sbin/.magisk/img), and the helper functions in util_functions.sh
will now transparently make existing modules install to the new location without any changes.
MagiskHide is also updated to unmount module files stored in this new location.
- Generalize avtab node extraction and insertion
- Add new supported rules: type_change, type_member
- Update help message with official policy language
Services can name their process name arbitrarily, for instance the service in
com.google.android.gms that is responsible for SafetyNet is named
com.google.android.gms.unstable. There are many apps out in the wild use
dedicated services with special names to detect root, and previously the user
is expected to add all of them to the hide list.
In this commit, we change from targeting process names to component names.
On Android, component names are composed of <pkg>/<cls>. When targeting
component names, we can always know what application spawned the new process.
This means that if the user adds a package name to the hidelist, MagiskHide can
now target ALL possible processes of that specific application.
To abide with this change, the default SafetyNet target is now changed from
com.google.android.gms.unstable (process name) to
com.google.android.gms/.droidguard.DroidGuardService (component name)
The database should only be accessed by a single process, which is magiskd.
This means 'magisk --sqlite [SQL]' has to be updated to pass the SQL command to the daemon.
In addition, open the database connection with SQLITE_OPEN_FULLMUTEX to support multithread in magiskd.
The utils function may be called in any situation, such as in daemon. We
should guarantee that all the resource got from this function released
normally.
Signed-off-by: yuchenlin <npes87184@gmail.com>
Introduce a new communication method between Magisk and Magisk Manager.
Magisk used to hardcode classnames and send broadcast/start activities to
specific components. This new method makes no assumption of any class names,
so Magisk Manager can easily be fully obfuscated.
In addition, the new method connects Magisk and Magisk Manager with random
abstract Linux sockets instead of socket files in filesystems, bypassing
file system complexities (selinux, permissions and such)
Boot services tend to fail in the middle when the kernel loads a sepolicy live.
It seems that moving full patch (allow magisk * * *) to late_start is still not enough to fix service startup failures.
So screw it, apply all patched in magiskinit, which makes sure that all rules are only loaded in a single step.
The only down side is that some OEM with a HUGE set of secontexts (e.g. Samsung) might suffer a slightly longer boot time, which IS the reason why the rules are split to 2 parts in the first place.
In previous versions, magiskinit will not early mount if /sepolicy is detected. However on OP5/5T latest betas, the devices are fully trebelized,
but for some reason the file /sepolicy still exists, making magiskinit think it is NOT a treble device and doesn't work properly.
So to properly fix this issue, I will have to use the "official" way - check fstab in device trees. Any block mentioned in the fstab in device trees
are supposed to be early mounted. Currently magiskinit will only mount system and vendor even if other partitions exists in the dtb fstab, since other
partitions are not used to construct sepolicy (currently).
These changes can also fix#373, since we dynamically detect PARTNAME from device trees.
BusyBox is unable to run properly on non-root applications due to seccomp introduced in Android 8.0.
The SDK-21 libc.a has system call wrappers that uses the system calls on the whitelist, so binaries compiled with the updated libc can work properly.
1. Introduce new applet: imgtool for better separation from the main program
2. Actually mount the image and check statvfs for free space in the image
This shall eliminate any possible module installation failure from image resizing issues.
The &cmd will return a pointer which point to a pointer of cmdline.
It is a memory address which is usually 8 bytes in 64 bits machine.
However, the struct cmdline is 4 bytes. This will cause setting zero
beyond the bound.
Below is a simple example to show the differentiation:
struct cmdline {
char skip_initramfs;
char slot[3];
};
static void parse_cmdline(struct cmdline *cmd)
{
printf("%lu\n", sizeof(*cmd)); /* 4 */
printf("%lu\n", sizeof(&cmd)); /* 8 */
}
int main()
{
struct cmdline cmd;
parse_cmdline(&cmd);
return 0;
}
This patch prevents this.
Signed-off-by: npes87184 <npes87184@gmail.com>
In previous implementations, proc_monitor checks whether the mount namespace of an app is actually separated from zygote using a list generated at startup.
However, for some unknown reason, some devices (e.g. Samsung) has multiple zygote servers running in the background.
This means that app processes spawned from the unlisted zygotes are not checked whether the separation is done or not, causing MagiskHide unmount stuffs in the namespace of zygote, and since zygote is the "mother" of all apps, all apps will no longer have root access.
Since I'm not sure of the reason why multiple zygotes exists, so instead of checking the namespace against a list, compare the current namespace against the parent process's namespace.
This will make sure the namespace is NOT the same as the parent process, which is supposed to be the zygote server.
