The error "mtk-su failed critical init step 3" occurs when the MediaTek-su (mtk-su) exploit tool is unable to initialize correctly on an Android device . This is common on devices like the Amazon Fire Tablet and Oppo smartphones when attempting to gain temporary root access . Understanding the Error
What it means: The exploit, which targets vulnerability CVE-2020-0069, has failed a vital setup phase . Why it happens:
Firmware Patch: Your device may have a security update released after March 2020 that patched the vulnerability .
Permission Issues: The binary may not have the correct execution permissions in the /data/local/tmp/ directory .
Incompatible Architecture: The tool only works on specific 64-bit MediaTek chipsets . Troubleshooting Steps permission denied mtk-su (#3) · Issue - GitLab
Run:
cat /proc/cmdline
If you see androidboot.selinux=enforcing with extra security flags (e.g., avb), the kernel might have hardened the exploit path.
If your bootloader is unlocked, flash an older stock ROM with a security patch from January 2020 or earlier. After downgrading, mtk-su will likely work perfectly. Warning: This exposes your device to known vulnerabilities; use only for testing or on a secondary device.
In mtk-su's internal process:
Failure at this stage means the exploit cannot proceed because the kernel or firmware patched the vulnerability, or the device’s security features blocked the operation.
Although rare, using the wrong binary version (e.g., running the 32-bit ARM binary on a 64-bit only kernel, or vice versa) can cause step 3 to fail. The memory offsets and IOCTL numbers differ between 32-bit and 64-bit environments.
mtk-su targets specific /dev/ nodes (e.g., /dev/ccci_data or /dev/mtk_cmdq). On newer Android versions (12, 13, 14), these nodes might have stricter permissions (e.g., 0660 root-only) or may not exist at all. If the exploit cannot open the required driver interface, it cannot proceed to step 3.
If you see failed critical init step 3 on your device, here’s your decision flowchart:
mtk-su versions and run with -s -f. If still failing, the OEM has hardened the kernel.mtk-su and install Magisk. It is safer, more stable, and actively maintained.mtk-su was a brilliant piece of engineering that democratized root access for budget MediaTek devices. But as the Android ecosystem matures, so do its defenses. The failed critical init step 3 error is not a bug—it’s a sign that your device is doing its job of protecting itself. Respect the patch level, and move to more robust methods when available.
Have you managed to get past step 3 on a patched device? Share your experience in the comments or on XDA Developers—the community always benefits from new discovery. mtk-su failed critical init step 3
"mtk-su: failed critical init step 3" is a known issue encountered when using the
tool (a script designed by "diplomatic" to exploit MediaTek vulnerabilities for temporary or bootless root access). This specific error typically indicates a failure during the initialization phase of the exploit, often related to permissions or system environment mismatches. about.gitlab.com Common Causes Permission Denied
: The script may not have the necessary execution permissions in the /data/local/tmp directory. System Patches
: Newer security updates from manufacturers (like Amazon for Fire tablets or Oppo) may have patched the specific vulnerability the tool relies on, causing it to fail at critical initialization steps. Architecture Mismatch
: Attempting to run a 32-bit version on a 64-bit system (or vice-versa) can lead to various initialization failures. Unstable Execution
: Users have reported that the exploit is occasionally unstable and may fail randomly on the first few attempts. about.gitlab.com Potential Fixes and Workarounds Re-issue Permissions : Ensure the file is executable. Users on suggest running chmod 755 mtk-su
multiple times if it fails initially, as it sometimes requires repeated attempts to "take". Run Multiple Times : Community members on
suggest simply trying to run the command again immediately after a failure. Verify Directory : Always ensure is placed in /data/local/tmp , as other directories often have flags that prevent the exploit from running. Check Compatibility
: Verify your device is still vulnerable. If you recently updated your firmware, the "Step 3" failure may be a sign that the exploit is no longer compatible with your current security patch. about.gitlab.com
For more specific troubleshooting, you can check the developer's original documentation on XDA-Developers or community-maintained versions like MTK Easy SU on GitHub Are you attempting this on an Amazon Fire tablet or a different MediaTek-based smartphone?
MTK-SU FAILED CRITICAL INIT STEP 3 ⚠️ Error Context This error occurs during the boot-up or execution phase of the MTK-SU (MediaTek Superuser) exploit tool. It indicates a failure in the kernel memory manipulation process required to gain temporary root access. 🔍 Root Causes
Security Patch Level: Your device has a security patch newer than March 2020.
Kernel Version: The specific kernel vulnerability (CVE-2020-0069) has been patched by the manufacturer.
Firmware Restrictions: Bootloader locks or read-only file systems are blocking the exploit's initialization. The error "mtk-su failed critical init step 3"
Architecture Mismatch: Attempting to run a 32-bit binary on a 64-bit architecture (or vice-versa) without proper libraries. 🛠️ Potential Fixes
Downgrade Firmware: Flash an older version of your device's ROM (pre-March 2020).
Check Architecture: Ensure you are using the correct version for your chipset (arm64 vs arm).
Clear Cache: Wipe the cache partition in recovery mode before retrying.
Alternative Tools: Use specialized tools like MTK Client or SP Flash Tool for deeper access. 🛑 Important Warning
MTK-SU is an old exploit. Most modern Android devices are no longer vulnerable. Continuing to force this script on patched hardware can lead to boot loops or permanent bricking. If you want to keep troubleshooting, tell me: Your device model Your Android version The security patch date (found in Settings > About Phone)
Step 3 failure almost always means the exploit is patched on your device. There is no workaround if the kernel vulnerability no longer exists. Proceed with unlocking the bootloader if you need root access.
The error message "mtk-su failed critical init step 3" typically indicates that the MediaTek (MTK) chipset's security exploit used by the tool has been blocked or is otherwise unable to initialize. Why This Error Happens Security Patches
: This is the most common cause. Manufacturers like Amazon (for Fire tablets) and others regularly release firmware updates that patch the specific vulnerability (CVE-2020-0069) that
relies on. If your device has a security patch date later than March 2020 , it is highly likely that will fail. Permissions
: The tool may lack the necessary execution permissions within the device's temporary directory. Incorrect Version
: Using a 32-bit version of the tool on a 64-bit architecture (or vice-versa) can trigger initialization failures. about.gitlab.com Potential Fixes Check Your Security Patch Level
Settings > About Tablet/Phone > Android Security Patch Level
. If it is newer than March 2020, the exploit is patched, and cannot work on your current firmware. Retry Permissions If you see androidboot
: Sometimes the error is a temporary glitch. Try re-running the command to set permissions before executing the script: Use code with caution. Copied to clipboard Wait a few seconds and try running Downgrade Firmware
: If your device allows it, you may need to downgrade to an older, unpatched firmware version to use this specific root method.
: Downgrading can be risky and may "brick" your device if not done correctly. Search for specific downgrade guides for your exact device model on XDA Developers Use the Latest Version : Ensure you are using the most recent release from the mtk-su XDA thread to ensure maximum compatibility with different kernels. about.gitlab.com alternative rooting method for your specific device model? permission denied mtk-su (#3) · Issue - GitLab
try running the directly again "chmod 755 mtk-su" I reissued the chmod 755 mtk-su. a third time and it eventually worked. about.gitlab.com
The error "mtk-su: failed critical init step 3" typically indicates that the MediaTek temporary root exploit is unable to gain the necessary permissions or establish the required environment to proceed with the privilege escalation. This specific step is often tied to a failure in setting up the command-line environment or a permission denial within the /data/local/tmp directory. What is mtk-su?
The mtk-su binary (and its wrapper app, MTK Easy SU) is a tool designed to provide "temporary root" access to devices powered by MediaTek chips. It exploits a vulnerability known as CVE-2020-0069, which allows unprivileged local users to read and write kernel memory. Unlike traditional rooting, this method is "bootless," meaning it does not modify the system or boot partitions and is lost upon a device reboot. Common Causes for Step 3 Failure
Permission Issues: The binary may not have the correct execution permissions (chmod 755) or is being run from a directory where execution is restricted.
Incompatible Firmware: Many manufacturers (like Amazon for Fire Tablets) patched the CVE-2020-0069 vulnerability in security updates released after March 2020. If your device is running newer firmware, the exploit will fail.
SELinux Interference: Secure Enhanced Linux (SELinux) might be blocking the exploit's attempt to transition into a new security context.
Processor Architecture Mismatch: Using a 32-bit binary on a 64-bit system (or vice versa) can lead to initialization errors. Troubleshooting and Fixes
If you encounter "failed critical init step 3," try the following steps in order: permission denied mtk-su (#3) · Issue - GitLab
Here’s a helpful post for anyone encountering the “mtk-su failed critical init step 3” error. You’re welcome to copy, adapt, or share it.
mtk-su supports arguments that can help bypass step 3 failures. Try:
./mtk-su -v # Verbose mode – watch where it fails
./mtk-su -s # Force a different escalation method
./mtk-su -f # Force exploit even if checks fail (risky)