The modern Android operating system is built on the Linux kernel, which implies a complex and multi-level security system. One of the fundamental aspects of this protection is the strict delineation of access rights to files, folders and system resources. When a user wonders how to change file permissions on Android, he most often faces one of two situations: either it is necessary to configure access for a specific application, or low-level intervention in the file system is required.
Under standard conditions, the average user is limited in his actions, since the system automatically manages access rights to ensure the stability of the device. However, if you have superuser rights or use specialized software tools, the ability to fine-tune file attributes opens up. Understanding the principles of the file system allows you not only to solve problems with running apps, but also to significantly increase the level of security of personal data.
In this guide, we will analyze in detail the mechanisms for managing permissions, from standard application settings in the menu to using the command line via ADB. You will learn how read, write and execute rights differ, as well as what risks rashly changing system attributes entails.
Standard application rights management in settings
The most common scenario for changing permissions concerns application access to smartphone functions: camera, microphone, contacts or storage. Starting with version Android 6.0 Marshmallow, Google has introduced a dynamic permissions model, which gives the user full control over what installed software can access.
No special utilities are required to manage these settings. Just go to the section Settings → Applications, select the app of interest and go to the “Permissions” item. Here you will see a list of all requested accesses with the ability to enable or disable them with a switch. This is a basic level of protection that prevents data leakage in the event of malware installation.
It is worth noting that some system applications may have mandatory permissions that cannot be revoked without obtaining root access or using special commands via USB debugging. If you try to disable critical access, the system may warn you that the app is unstable or completely block changing the setting.
- 📱 Access to the camera allows applications to take photos and record videos without your knowledge.
- 📍 Geolocation transmits the exact coordinates of the device to developer servers or advertising networks.
- 📞 reading call and SMS logs is often used by banking applications for verification, but can be dangerous in the hands of fraudsters.
- 💾 Access to the storage makes it possible to read and delete any files in the internal memory.
Regular revision of issued permits is a good habit for maintaining digital hygiene. Go to your privacy settings and check which apps have access to your microphone right now. It often turns out that a simple flashlight or calculator requests access to contacts, which is a clear sign of the developer’s dishonesty.
File system and file attributes: theoretical basis
To understand how to change file permissions on Android at a deep level, you need to refer to the theory of the ext4 or f2fs file system, which are used in most modern devices. On Linux-like systems, each file has a set of attributes that determine who can do what with it. These rights are divided into three categories for three user groups: owner, group and others.
Each category can have three types of rights: Read, Write and Execute. In numerical representation they are coded as 4, 2 and 1 respectively. The sum of these values forms the final numeric resolution, for example, 755 or 644. Numerical notation is the standard for setting rights through the terminal.
Changing these bits directly affects the behavior of the operating system when trying to access an object. If an executable script file does not have the execute bit, the system will refuse to run it, even if the user is the owner. Likewise, lack of write permissions will prevent applications from saving data in a specific directory.
⚠️ Warning: Incorrectly changing the permissions of system files in the root of the /system partition may cause the device to fail to boot (bootloop). Always create a full backup before making changes to system directories.
Use root-enabled file managers such as Solid Explorer or MiXplorer to visually change permissions without entering commands.
In the context of mobile devices, most user files are stored in /sdcard or /storage partitions, which are often mounted with permissions allowing free access all applications. However, system libraries and executable files in /system/bin or /data are protected by strict restrictions, which can only be bypassed with superuser privileges.
Using file managers with Root access
For those who do not want to use the command line, there are advanced file managers that can work with superuser rights. After obtaining root access through Magisk or SU, applications such as Root Explorer or FX File Explorer are able to change the attributes of files and folders.
The process of changing rights in the graphical interface is usually intuitive. You need to long press on the file, select “Properties” or “Permissions” and see a table with checkmarks. Here you can visually mark what actions are allowed to the owner, group and other users. The interface often duplicates the numeric representation of rights, showing code like rw-r--r--.
You may need to remount the partition to write mode before making changes. Some managers do this automatically upon request, others require manual intervention through the app settings.
| Permission code | Symbolic designation | Description of action | Usage example |
|---|---|---|---|
| 4 | r | Reading (Read) | Viewing the contents of a file or a list of files in a folder |
| 2 | w | Write (Write) | Editing a file, deleting or creating new files |
| 1 | x | Execute | Running a script or app, entering directory |
| 7 | rwx | Full control | The owner of the file usually has full rights |
Be extremely careful when working with such tools. Accidentally removing the execution bit from a system library can lead to a crash of the corresponding service. If you are not sure of the purpose of the file, it is better not to change its attributes.
Changing permissions through ADB and the command line
The most flexible and professional way to manage permissions is to use the Android Debug Bridge (ADB). This method does not always require root access on the device itself if the changes concern user data, but for system files, superuser access is required.
To get started, you need to enable USB debugging in the “For Developers” menu and connect the smartphone to the computer. After installing the ADB drivers and utilities, you can send commands directly to the device shell. This allows you to script processes for changing rights and apply them en masse.
The main command for changing rights is chmod. The syntax is as follows: chmod [rights] [path_to_file]. For example, to make a script executable, the command chmod 755 /data/local/tmp/script.shis used. To change the owner of the file, use the command chown.
adb shellsu
chmod 644 /sdcard/Download/config.txt
chown root:root /system/app/MyApp.apk
☑️ Preparing to work with ADB
Using an emulator terminal directly on the device, such as Termux, also allows you to execute these commands without connecting to a PC. However, in this case, having superuser rights is a prerequisite for changing the attributes of files outside the application's home directory.
Features of working with the Data section and SD card
File systems on external drives and internal emulated storage have their own characteristics. Section /sdcard in modern versions of Android is often an emulation, where real access rights are replaced by FUSE (Filesystem in Userspace) rules. This means that classic commands chmod may not work as expected.
On SD cards formatted in the FAT32 or exFAT file system, there is no concept of Linux access rights at all. These file systems do not support owner and group attributes. When mounting such a card, all files automatically receive the rights specified by the mount parameters, usually readable and writable by all users.
If you are faced with a situation where an application cannot write a file to an SD card, the problem most often lies not in the file rights, but in Android’s access restrictions to external drives introduced for security purposes. Starting from Android 11, access to the root of an external card is strictly regulated.
⚠️ Attention: Formatting an SD card as internal storage (Adoptable Storage) encrypts the data and binds the card to a specific device. In this mode, standard Linux permissions are applied, but the card will become unreadable on other devices.
To resolve problems with writing to external media, it is sometimes necessary to grant the application special permission through the "Access all files" menu or use the system API Storage Access Framework. Directly changing the permissions bits on such media is technically impossible without reformatting them into the native Linux format (ext4), which is not supported by the standard tools of most smartphones.
Compatibility issues and consequences of changes
Changing file permissions is a powerful tool that can either solve a problem or create a new one. A mismatch between expected rights and actual attributes often leads to errors like “Permission Denied” when launching applications or scripts. This is especially true for enthusiasts installing modified firmware or system modules.
Some applications, when detecting changed rights to their own files, may refuse to start, considering this a sign of hacking or integrity violations. Banking applications and games with anti-cheat protection are especially sensitive to such manipulations and can block access to your account.
In addition, updating the operating system can reset all manually changed rights in system sections, since the updater checks checksums and file attributes. This may result in previously working modifications no longer functioning after the first OTA update.
What is SELinux and how does it affect rights?
SELinux (Security-Enhanced Linux) is an additional security system that imposes restrictions on top of standard Linux rights. Even if you set permissions to 777 (full access for everyone), SELinux may block access if the file's security context does not match the policy. To temporarily disable, use the setenforce 0 command, but this reduces the security of the device.
Always check the system logs via logcatif something stops working after changing the rights. Access errors are usually clearly recorded in the system log, indicating the specific file and type of prohibited operation, which helps to quickly diagnose the cause of the failure.
Restoring default rights
If experiments with permissions have led to unstable operation of the system, the most reliable way to restore is to reset rights to factory values. In custom recovery, such as TWRP, there is often a “Fix Permissions” function, which scans partitions and restores standard attributes according to the firmware installation scripts.
An alternative method is to re-flash the device while saving user data (Dirty Flash). This process overwrites the system partition with the original files with the correct permissions, without affecting the user data partition. This is an effective way to correct errors caused by accidental removal of system bits.
For individual files, you can try to copy their rights from a similar file on a working device or from stock firmware using the command chmod --referenceif the file manager or terminal supports such an option. However, the only guaranteed solution is a complete reinstallation of the system software.
⚠️ Attention: Menu interfaces and item names may differ depending on the manufacturer’s shell (MIUI, OneUI, ColorOS). If you do not find the described items, use the settings search or check the documentation for your specific model.
Restoring rights through the recovery menu is the safest way to correct errors after unsuccessful experiments with system files without losing personal data.
Regularly creating backups of the current system configuration before making any changes to the file structure is golden modding rule. Tools like Titanium Backup or built-in recovery backup tools allow you to save not only data, but also the current state of access rights, which makes it easier to roll back changes in case of failure.
Frequently asked questions (FAQ)
Is it possible to change file permissions without root access?
It is impossible to change the rights of system files or files of other applications without root access due to the Android security architecture. You can only manage access rights within the application's own sandbox or through the standard permissions menu for device functions (camera, microphone).
What does the "Permission denied" error mean when copying files?
This error means that the current user or application does not have enough rights to read the source file or write to the target directory. This often happens when you try to copy files from a protected system folder to a user storage without superuser rights.
Is it safe to set permissions to 777 for all files?
No, this is extremely unsafe. Permission 777 gives full read, write, and execute access to any process on the system. This opens up vulnerabilities, allowing malware to modify critical files or run dangerous scripts on behalf of the file owner.
How to find the current file permissions through your phone?
You can use file managers with root support (for example, Solid Explorer) by going to the file properties. Or use the terminal (Termux) and enter the command ls -l /path/to/filewhich will display the symbolic and numeric representation of rights.
Why are file rights reset after a reboot?
This happens if you change the rights in partition that is mounted with settings that ignore attribute changes, or if the system forces integrity checksums to be restored at boot. This is also typical for temporary file systems (tmpfs).