If you're seeing the "mtk-su failed critical init step 3" error, it typically means the exploit is having trouble initializing the root process on your MediaTek device. This is often due to recent security patches or incorrect execution permissions. Troubleshooting "Critical Init Step 3"
Repeat Permissions: Sometimes the initialization fails simply because the binary wasn't correctly flagged as executable in that specific session. Try re-running chmod 755 mtk-su directly before attempting the exploit again.
Verify Device Compatibility: MTK-SU targets specific MediaTek processors (e.g., MT6737, MT6765, MT8163). If your device has a newer security patch (post-March 2020), the kernel vulnerability it relies on may have been patched, leading to initialization failures.
Check for "Expert Root" Mode: If you are using a wrapper app like MTK Easy SU, ensure you haven't enabled "Expert Mode" unless you have the specific recovery images required for your model, as this can cause the process to fail at early steps.
Restart and Clear: A simple system restart can clear hung processes in the /data/local/tmp directory that might be blocking the exploit from hooking into the kernel. Common Fixes from the Community
Persistent Retries: Users on GitLab and XDA Developers have noted that running the command multiple times—sometimes up to three or four—eventually allows the exploit to bypass the initialization hurdle.
Update the Binary: Ensure you are using the latest version of the mtk-su binary. Older versions frequently fail on devices with slightly updated firmware.
Environment Check: Make sure you are running the command from the correct directory (usually /data/local/tmp) where you have read/write/execute permissions as a shell user.
What is the specific model and Android security patch date of your device?
Here’s a post you can use for a forum, Reddit (like r/androidroot or r/androidafterlife), or a tech support thread:
Title: Help: mtk-su failing at “critical init step 3” – any fixes?
Post:
I’m trying to get temporary root on my MediaTek device using mtk-su, but I keep getting stuck at:
critical init step 3
Failed critical init step 3
Device info:
What I’ve tried so far:
mtk-su (r22, r23, r24)chmod 755 on the binaryWhat I’ve read:
Step 3 usually fails when an expected kernel or device node isn’t found, or when the exploit’s address offsets don’t match the kernel. Some say it’s patched on later MediaTek chips (like MT6765, MT6762, or newer), or when the kernel has CFI or PAN enabled.
Questions:
mtk-su?Any insight would be appreciated. I’m not trying to flash anything yet – just need temporary shell root for backup purposes.
Thanks in advance.
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. 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)
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. If you're seeing the "mtk-su failed critical init
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
The error is not a generic "something went wrong." It is a specific indicator that the exploit’s core vulnerability has been mitigated. Here are the primary reasons:
If your device has a 64-bit kernel but you are running a 32-bit shell environment (common when using some terminal emulators from the Play Store), the exploit may miscalculate memory offsets, leading to a step 3 failure. Always use a 64-bit terminal or ADB from a 64-bit platform tools build.
To understand why step 3 fails, we must understand the steps that mtk-su takes internally. While the source code is not fully public (to prevent malicious repurposing), reverse engineering and community analysis have pieced together the general flow:
/proc or /sys entry points related to the MediaTek CCCI (Cross-Core Communication Interface) or similar kernel driver./system/bin/sh) with the newly acquired privileges."Failed critical init step 3" means that the exploit’s attempt to trigger the memory corruption or privilege escalation primitive was rejected or did not produce the expected result. The kernel driver either ignored the malformed command, blocked it, or the memory address the exploit was trying to overwrite was no longer accessible.
Go to Settings → About phone → Android security patch level.
If your bootloader can be unlocked (e.g., Xiaomi, OnePlus, Realme), forget mtk-su entirely. Unlock the bootloader, patch the boot.img with Magisk, and flash it. This provides permanent, stable root without exploiting any vulnerabilities.
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.
If you are determined to get mtk-su working, follow these diagnostic steps. Title: Help: mtk-su failing at “critical init step
The mtk-su exploit is not a "one size fits all" tool. It relies on specific hardware vulnerabilities in MediaTek (MTK) chipsets.
diplomatic / xyz) supports a wider range of newer chips.mtk-su. Conversely, if you have an older device and are trying a new binary, try an older version.