Comprehensive Analysis and Practical Guide for Resolving ADB Permission Issues on Android Devices in Ubuntu Linux

Problem Background and Phenomenon Analysis

In Android application development, deploying applications directly to physical devices for testing is a crucial step. However, when using ADB (Android Debug Bridge) to connect Android devices on Ubuntu Linux systems, developers often encounter device permission issues, specifically manifested as ???????????? no permissions output after executing the adb devices command.

Root Causes of Permission Issues

The Linux system manages device permissions through udev rules. When an Android device connects to the Ubuntu system via USB, the system requires correct udev rules to grant the current user access permissions to the device. By default, regular users may not have sufficient permissions to access USB devices, preventing ADB from properly recognizing and connecting to devices.

Solution Implementation Steps

Method 1: Restart ADB Server (Recommended)

Based on the practical experience from the best answer, the simplest solution is to restart the ADB server with administrator privileges:

sudo adb kill-server
sudo adb start-server
adb devices

This method forces the system to rescan and recognize connected USB devices by reinitializing the ADB service process, quickly resolving the issue in most cases.

Method 2: Configure udev Rules (Comprehensive Solution)

For a more permanent solution, system udev rules need to be configured. First, ensure the user is added to the plugdev group:

sudo usermod -aG plugdev $LOGNAME

Then create or update the udev rules file. For Samsung devices (vendor ID 04E8), create the file /etc/udev/rules.d/51-android.rules:

SUBSYSTEM=="usb", ATTR{idVendor}=="04E8", MODE="0666", GROUP="plugdev"

Set correct file permissions and restart the udev service:

sudo chmod 644 /etc/udev/rules.d/51-android.rules
sudo chown root:root /etc/udev/rules.d/51-android.rules
sudo service udev restart

Method 3: Use Community-Maintained Rule Sets

For environments requiring support for multiple Android devices, install the community-maintained complete rule set:

sudo apt-get install android-sdk-platform-tools-common

This package contains udev rules for most common Android device manufacturers, providing more comprehensive device support.

Device-Side Configuration Requirements

In addition to computer-side configuration, the Android device itself requires proper setup:

• Enable Unknown sources in Settings > Security
• Enable USB debugging in Settings > Developer options
• Ensure android:debuggable="true" in the project's AndroidManifest.xml file

Troubleshooting and Verification

After completing configuration, execute the following steps to verify the solution:

1. Disconnect USB connection
2. Reconnect the device
3. Execute adb devices command
4. Confirm the device is listed normally, rather than showing permission errors

Advanced Configuration Options

For environments requiring finer permission control, use user-specific configurations:

SUBSYSTEM=="usb", ATTR{idVendor}=="04E8", OWNER="$USER", GROUP="plugdev", MODE="0660"

Replace $USER with the actual username; this approach provides better security.

Conclusion and Best Practices

Through analysis of Q&A data and official documentation, we conclude that restarting the ADB server is the fastest and most effective temporary solution, while configuring correct udev rules provides long-term stable device access. It is recommended that developers performing Android development on Ubuntu systems prioritize Method 1 for quick troubleshooting while configuring complete udev rule sets to ensure compatibility with all Android devices.