The error "mtk-su failed critical init step 3" usually appears when you're trying to use the mtk-su tool to get temporary root access on MediaTek-based devices, like the Amazon Fire 7 (2019). Why this happens
This specific error indicates a failure during the initial exploit setup phase. While the tool developer, "diplomatic," hasn't released a public "error code manual," community consensus and logs show this usually means:
Patched Firmware: Amazon and other manufacturers released security updates that patched the kernel vulnerability (CVE-2020-0041 or similar) used by mtk-su. If your tablet is on a newer version of FireOS, the exploit will fail at an early step.
Incompatible Kernel: The tool is designed for specific MediaTek ARMv8 (64-bit) kernels. If the kernel has been hardened or uses a different memory layout than what the script expects, it triggers a "critical init" failure.
Permissions: Occasionally, this can happen if the binary isn't executed with the correct permissions from /data/local/tmp. Troubleshooting Steps
Check Firmware Version: Many Fire tablets updated after early 2020 are patched. If you are on FireOS 6.3.1.2 or higher (depending on the model), this software-based exploit may no longer work.
Verify Binary Location: Ensure you have pushed the file to the correct directory and set execution permissions:
adb push mtk-su /data/local/tmp/ adb shell chmod +x /data/local/tmp/mtk-su /data/local/tmp/mtk-su Use code with caution. Copied to clipboard
Try MTK-Easy-SU: If you are using the command line, try the MTK-Easy-SU app interface, which sometimes handles the initialization more reliably for specific devices.
If you continue to see "Step 3" or "Step 4" failures after verifying these steps, the exploit is likely fully patched on your current firmware. In these cases, your only option is typically a hardware-based "brick-and-short" method (if available for your model) to unlock the bootloader via XDA Developers guides.
Do you know the exact FireOS version currently running on your tablet?
Understanding and Troubleshooting "mtk-su Failed Critical Init Step 3"
If you are seeing the error "mtk-su failed critical init step 3", it means the mtk-su exploit tool—used to gain temporary root access on MediaTek-based Android devices—has failed to initialize its core memory manipulation routine. This specific error typically indicates that the exploit has been patched by your device manufacturer or that the tool cannot find the necessary memory offsets to proceed. What is mtk-su?
mtk-su is a specialized exploit binary (often used via the MTK Easy SU app) that leverages a critical vulnerability (CVE-2020-0069) found in many MediaTek chipsets. It allows for "bootless" or "temporary" root access without needing to unlock the bootloader. Why "Critical Init Step 3" Fails
The initialization process for mtk-su involves several internal steps to prepare the device's kernel for privilege escalation.
Step 3 specifically relates to the tool's attempt to map or write to kernel memory.
The Main Cause: Most often, this error occurs because the device is running a security patch from March 2020 or later. Google and MediaTek released a fix for this vulnerability that prevents the exploit from starting.
Incompatibility: Newer chips (like those in the Fire HD 8 10th Gen or newer Oppo models) may use a kernel architecture that mtk-su does not support. Potential Fixes and Workarounds mtk-su failed critical init step 3
While a system patch usually makes the exploit impossible to run, you can try these steps to rule out software glitches: 1. Re-issue Permissions and Commands
Sometimes the binary fails because it lacks the correct execution permissions in the temporary directory. Connect your device via ADB.
Navigate to the directory where you pushed the file (usually /data/local/tmp).
Run the following command again to ensure it is executable:chmod 755 mtk-su
Attempt to run ./mtk-su multiple times; some users report it working after 3-4 consecutive tries. 2. Clear App Data (For MTK Easy SU Users)
If you are using the MTK Easy SU app from GitHub, a corrupted "asset" or configuration can cause initialization failures. Go to Settings > Apps > MTK Easy SU. Select Clear Data and Clear Cache.
Re-open the app, ensure you have an active internet connection to download required assets, and try again. 3. Check for Firmware Downgrades
"mtk-su: failed critical init step 3" is a known issue encountered by users attempting to gain temporary root access on MediaTek-based Android devices, most notably Amazon Fire tablets . This error typically signals that the
exploit has failed to initialize its protocol, often because the specific security vulnerability it relies on has been patched by the manufacturer. Core Causes of Step 3 Failure Security Patches
: The most common reason for this error is a firmware update that has patched the "MediaTek-su" vulnerability. Manufacturers like Amazon frequently release OTA (Over-The-Air) updates specifically to block such exploits. Incompatible Hardware/Firmware
: The exploit is designed for specific MediaTek chipsets and older Android security patch levels. Newer models, such as the Fire HD 8 (10th Gen), are often reported as incompatible with the standard Permission Issues
: If the binary does not have the correct execution permissions or is being run from a restricted directory, it may fail during the initialization phase. Potential Fixes and Workarounds
While "Step 3" often indicates a definitive patch that cannot be bypassed on that specific firmware, users in the community have suggested several troubleshooting steps: Reset Permissions
: Ensure the binary has the correct execution rights. From the /data/local/tmp directory, run: chmod 755 mtk-su
Some users report that running this command multiple times or re-issuing it before execution occasionally resolves transient initialization errors. Use Correct Directory : The binary must be pushed to and executed from /data/local/tmp
, as this is often the only writable directory accessible via ADB without prior root. Check mtk-su Version
: Ensure you are using the latest or most appropriate version of the tool. For example, version The error "mtk-su failed critical init step 3"
was released to address issues on certain newer chipsets, though it still may not work on fully patched devices. Downgrade Firmware : If the device supports it, some users attempt to downgrade their firmware
to a version that predates the security patch, though this carries a high risk of "bricking" the device. Alternative Tools
continues to fail, users often turn to managed applications that package these exploits: MTK Easy SU : A graphical wrapper for the exploit available on
that can sometimes automate the process or provide clearer error logs for troubleshooting. Are you trying to root a specific Amazon Fire model or a different
The error "failed critical init step 3" in mtk-su typically indicates that the MediaTek temporary root exploit is being blocked by your device's security measures. This most often happens because the specific vulnerability mtk-su uses has been patched via a firmware update. Why This Happens
Patched Exploit: Your device's security patch level is too new for the mtk-su binary to bypass the kernel protection.
Incompatible Platform: While less common for "Step 3," this can also occur if the binary is targeting the wrong architecture (e.g., trying to run a 64-bit binary on a 32-bit armv7l machine).
Temporary Initialization Glitch: In some rare cases, it is a one-off execution error. Step-by-Step Troubleshooting Guide 1. The "Try Again" Method
Before assuming a patch, try to rule out simple execution errors. Re-issue the permissions: chmod 755 mtk-su.
Run the command again. Some users report success after multiple attempts. 2. Verify Architecture Ensure you are using the correct binary for your hardware. Check your architecture: Run uname -m in your terminal. If it says armv7l, use the 32-bit binary. If it says aarch64, use the 64-bit binary. 3. Downgrade Firmware (Advanced)
If the exploit is patched, the only way to make mtk-su work is to revert to an older, vulnerable version of your device's software.
Find Firmware: Search for your specific device model on sites like XDA-Developers to find official older firmware.
Flash Tool: Use a tool like SP Flash Tool (for MediaTek devices) to flash the older version.
⚠️ Warning: Flashing firmware carries a risk of "hard-bricking" your device if done incorrectly. 4. Use Alternative Rooting Methods
If mtk-su is permanently patched, you may need a more robust method that doesn't rely on this specific vulnerability:
mtkclient: A powerful tool for modern MediaTek devices that can often bypass locked bootloaders to flash a patched Magisk boot image.
Magisk (Official Method): If you can unlock your bootloader via official channels, download the Magisk App to patch your device's boot.img and flash it via fastboot. Summary Table Likely Solution Execution Glitch Run chmod 755 and retry the command 2–3 times. Wrong Binary Step 2: Use the Correct Version of mtk-su
Ensure you are using 32-bit for armv7l or 64-bit for aarch64. Security Patch
Downgrade firmware or use mtkclient to unlock the bootloader.
Have you checked your device's security patch date in Settings to see if it matches known patched versions for your model? permission denied mtk-su (#3) · Issue - GitLab
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
mtk-suDo not use ancient versions like v18 or v22. Download the latest official build (usually v33 or r24) from the original XDA thread. Place it in /data/local/tmp and set permissions:
adb push mtk-su /data/local/tmp/
adb shell chmod 755 /data/local/tmp/mtk-su
When the exploit fails specifically at step 3, it means the first two steps succeeded—the vulnerability was triggered, and memory corruption likely occurred. However, when mtk-su attempted to finalize the privilege escalation (i.e., give your shell root permissions), the kernel either refused the operation or the process became unstable.
In simpler terms: You picked the lock, turned the key, but the door jammed. Step 3 is the most delicate part of the exploit because it requires the kernel to be in a very specific state.
In the niche world of Android device modification and exploitation, few tools have garnered as much attention in recent years as mtk-su. Developed by veteran exploit hunter XDA Recognized Contributor diplomatic, this tool was a game-changer for owners of MediaTek (MTK) powered Android devices. It offered a reliable method to gain temporary root (shell root) access without needing to unlock the bootloader or flash custom recovery.
However, as Android security evolved and MediaTek patched vulnerabilities, many users began encountering a frustrating roadblock. After running the command, instead of a # prompt, they were met with a cryptic error message:
"Failed critical init step 3"
For the uninitiated, this error signals a dead end. But what does it actually mean? Why does it happen on some devices and not others? And most importantly, is there any way around it?
This article dives deep into the mechanics of mtk-su, the significance of "step 3," and what you can do if you see this error on your screen.
mtk-su comes in different versions (e.g., v29, v33, r20). Not all builds support all MediaTek chips (Helio P60, G90T, Dimensity series, etc.). If you are using a version that doesn’t fully support your kernel's specific structures, the exploit may hang or fail at step 3. The Dimensity series (MT6889, MT6893) is particularly problematic since they use a newer kernel branch (4.14+).
