: Some systems, especially those derived from System V (like Solaris), have a version of su that does not require the target user's password if the invoking user is a member of a specific group (usually wheel or root ).
In the context of , the su binary is the specific file placed into the system partition (usually /system/bin/su or /system/xbin/su ) to grant apps administrative privileges. Without this binary, an Android device is "unrooted," meaning apps are confined to a "sandbox" where they cannot modify system files or access other apps' data. 🛠️ How su Binaries Work
| Binary | Source | Key Features | |--------|--------|--------------| | | Magisk (modern) | Systemless root, hide root from detection, module support | | SuperSU | Chainfire (legacy) | Full control, per-app permissions, now outdated | | LineageOS su | LineageOS built-in | Simple root addon (deprecated in newer builds) | | KernelSU | Kernel-based | Root via kernel module, supports GKI kernels | su binaries
The use of su binaries involves significant security considerations. Allowing or restricting access to su can prevent unauthorized users from gaining elevated privileges.
// su_minimal.c #include <stdio.h> #include <unistd.h> #include <sys/types.h> : Some systems, especially those derived from System
An alternative to using su for many administrative tasks is sudo , which allows authorized users to execute specific commands with elevated privileges without needing to know the root password. sudo provides a more granular control over user permissions and is generally considered more secure and easier to manage than su .
To mitigate potential risks associated with the use of su , several best practices should be adopted: 🛠️ How su Binaries Work | Binary |
The way su binaries are handled has changed significantly over the years to keep up with Android's tightening security: SuperSU (System-Based)