"Parcel object increased from 104 to 120 bytes, and many functions in both libraries had two Parcel objects next to each other in their stack.
Each of those functions had their stack modified to be increased by 32 bytes to accommodate for the increased Parcel object size. The stack pointer offsets for the 2nd Parcel, along with any other items in the stack after the Parcels (which was just the stack canary), were also adjusted to accomodate for the change in Parcel size."
Source: https://github.com/jabashque/proprietary_vendor_leeco/commit/652378f8839f2851a65334a0c659d7ba06fd29cc (@jabashque)
On Android 14, Goodix just straight showing a stack corruption in the logcat everytime it tries to read fingerprint in Fingerprint setup:
--------- beginning of crash
F libc : stack corruption detected (-fstack-protector)
F libc : Fatal signal 6 (SIGABRT), code -1 (SI_QUEUE) in tid 1498 (android.hardwar), pid 1498 (android.hardwar)
F DEBUG : *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
F DEBUG : Build fingerprint: 'Nokia/TA-1004_00WW/NB1:8.1.0/OPR1.170623.026/00WW_4_88B:user/release-keys'
F DEBUG : Revision: '0'
F DEBUG : ABI: 'arm64'
F DEBUG : Timestamp: 1974-12-17 06:27:08.153688959+0100
F DEBUG : Process uptime: 3s
F DEBUG : Cmdline: /vendor/bin/hw/android.hardware.biometrics.fingerprint@2.1-service
F DEBUG : pid: 1498, tid: 1498, name: android.hardwar >>> /vendor/bin/hw/android.hardware.biometrics.fingerprint@2.1-service <<<
F DEBUG : uid: 1000
F DEBUG : signal 6 (SIGABRT), code -1 (SI_QUEUE), fault addr --------
F DEBUG : Abort message: 'stack corruption detected (-fstack-protector)'
F DEBUG : x0 0000000000000000 x1 00000000000005da x2 0000000000000006 x3 0000007ffe25efb0
F DEBUG : x4 607372652c271f63 x5 607372652c271f63 x6 607372652c271f63 x7 7f7f7f7f7f7f7f7f
F DEBUG : x8 00000000000000f0 x9 0000007385260e28 x10 0000000000000001 x11 00000073852d9e20
F DEBUG : x12 0000000000000018 x13 000000001c3df18c x14 0005c3055f263c3b x15 00000000000018fe
F DEBUG : x16 00000073853429f0 x17 000000738531cfb0 x18 0000007386996000 x19 00000000000005da
F DEBUG : x20 00000000000005da x21 00000000ffffffff x22 0000007385558590 x23 0000007ffe25f0c8
F DEBUG : x24 0000007ffe25f220 x25 000000737e00c200 x26 0000000000000000 x27 0000000000000000
F DEBUG : x28 00000072fdb22fa0 x29 0000007ffe25f030
F DEBUG : lr 00000073852cb7b8 sp 0000007ffe25ef90 pc 00000073852cb7e4 pst 0000000000000000
F DEBUG : 11 total frames
F DEBUG : backtrace:
F DEBUG : #00 pc 00000000000927e4 /apex/com.android.runtime/lib64/bionic/libc.so (abort+164) (BuildId: bbbe5750122b349e49dac3085bb24953)
F DEBUG : #01 pc 00000000000a7b5c /apex/com.android.runtime/lib64/bionic/libc.so (__stack_chk_fail+20) (BuildId: bbbe5750122b349e49dac3085bb24953)
F DEBUG : #02 pc 0000000000019124 /vendor/lib64/libfp_client.so (BpFingerPrintService::connect(android::sp<android::IFingerPrintClient> const&, int)+388) (BuildId: 3eadc9c3617ea1d96f75b815145b53e889b9d111)
F DEBUG : #03 pc 0000000000013aa8 /vendor/lib64/libfp_client.so (android::Fp::connect(int)+204) (BuildId: 3eadc9c3617ea1d96f75b815145b53e889b9d111)
F DEBUG : #04 pc 000000000000aff8 /vendor/lib64/hw/fingerprint.msm8998.so (goodix_sensor_init+368) (BuildId: cd1a431095b806c2d41101654467f3436e55960c)
F DEBUG : #05 pc 000000000000b244 /vendor/lib64/hw/fingerprint.msm8998.so (goodix_sensor_set_active_group+96) (BuildId: cd1a431095b806c2d41101654467f3436e55960c)
F DEBUG : #06 pc 0000000000007f24 /vendor/lib64/hw/fingerprint.msm8998.so (BuildId: cd1a431095b806c2d41101654467f3436e55960c)
F DEBUG : #07 pc 00000000000030e4 /vendor/bin/hw/android.hardware.biometrics.fingerprint@2.1-service (android::hardware::biometrics::fingerprint::V2_1::implementation::BiometricsFingerprint::openHal()+144) (BuildId: a2041c9cf6813aee7ad784cec3edd176)
F DEBUG : #08 pc 0000000000003708 /vendor/bin/hw/android.hardware.biometrics.fingerprint@2.1-service (android::hardware::biometrics::fingerprint::V2_1::implementation::BiometricsFingerprint::getInstance()+84) (BuildId: a2041c9cf6813aee7ad784cec3edd176)
F DEBUG : #09 pc 0000000000003d18 /vendor/bin/hw/android.hardware.biometrics.fingerprint@2.1-service (main+28) (BuildId: a2041c9cf6813aee7ad784cec3edd176)
F DEBUG : #10 pc 000000000008b3f8 /apex/com.android.runtime/lib64/bionic/libc.so (__libc_init+104) (BuildId: bbbe5750122b349e49dac3085bb24953)
Let's roll.
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Python 3.10, pwnlib installed.
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Ghidra
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2 brain cells
pwnlibs installation guide:
sudo apt-get update
sudo apt-get install python3 python3-pip python3-dev git libssl-dev libffi-dev build-essential
python3 -m pip install --upgrade pip
python3 -m pip install --upgrade pwntools
-
Open Ghidra.
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Create a new project and import all of the Goodix fingerprint libraries into that project.
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You have to analyze all of them. It's required.
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Export the library to C/C++ (Go to File -> Export Program...)
Use these configuration:
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Format: C/C++
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Output File: Wherever you want to export the codes to. In my case, I'll extract to
exportedfolder.
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After all blobs are exported into C format, you will get a file that ends in .c format.
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Run this for each file.
grep -B10 "Parcel aPStack" <path_to_exported_library>.c | grep "//" > <output_path>_f
This may returns line with Warning in, so remove every line contains that.
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Now you have to disassemble all libraries.
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First of all, let's install AARCH64 toolchain.
sudo apt-get install binutils-aarch64-linux-gnu
- Then disassemble every file using this command:
aarch64-linux-gnu-objdump -d <path_to_library>.so > <path_to_output_asm>.asm
- Replace config lines in
script.pyfor each file.
asm_file = "<path_to_output_asm>.asm"
functions_file = "<output_path>_f"
output_file = "<path_to_library>.so"
- Run the script:
python script.py
This will overwrite <path_to_library>.
There might be something like FAIL or FAIL1, but just ignore it because it won't damage anything.
And that's it, now you got Goodix fingerprint blobs patched and ready to go!