platform_system_core/init/fuzzer
Nikita Ioffe a66adf45aa init selinux.cpp: use a better way to detect if we run in Microdroid
We are now conditionally compiling init binaries & libinit for
Microdroid (adding -DMICRODROID=1 cflag), so instead of checking for the
presence of the /system/etc/selinux/microdroid_precompiled_sepolicy we
can check if the code is compiled for Microdroid.

In a follow-up changes we can split the sepolicy loading logic into 2
separate headers (one for Android and one for Microdroid) and include
the necessary one depending on the target we compile for.

Bug: 287206497
Test: atest MicrodroidTestApp
Change-Id: Id9c837d03a96ff9564688d33955ec85094eee487
2023-06-26 16:43:16 +01:00
..
Android.bp init selinux.cpp: use a better way to detect if we run in Microdroid 2023-06-26 16:43:16 +01:00
init_parser_fuzzer.cpp Make the host_init_verifier init.rc parser follow symlinks. 2023-03-17 02:47:21 +00:00
init_property_fuzzer.cpp
init_ueventHandler_fuzzer.cpp Added init_ueventHandler_fuzzer 2022-08-19 11:48:30 +05:30
README.md Added init_ueventHandler_fuzzer 2022-08-19 11:48:30 +05:30

Fuzzers for libinit

Table of contents

Fuzzer for InitParser

InitParser supports the following parameters:

  1. ValidPathNames (parameter name: "kValidPaths")
  2. ValidParseInputs (parameter name: "kValidInputs")
Parameter Valid Values Configured Value
kValidPaths 0./system/etc/init/hw/init.rc,
1./system/etc/init
Value obtained from FuzzedDataProvider
kValidInputs 0.{"","cpu", "10", "10"},
1.{"","RLIM_CPU", "10", "10"},
2.{"","12", "unlimited", "10"},
3.{"","13", "-1", "10"},
4.{"","14", "10", "unlimited"},
5.{"","15", "10", "-1"}
Value obtained from FuzzedDataProvider

Steps to run

  1. Build the fuzzer
  $ mm -j$(nproc) init_parser_fuzzer
  1. Run on device
  $ adb sync data
  $ adb shell /data/fuzz/arm64/init_parser_fuzzer/init_parser_fuzzer

Fuzzer for InitProperty

InitProperty supports the following parameters: PropertyType (parameter name: "PropertyType")

Parameter Valid Values Configured Value
PropertyType 0.STRING,
1.BOOL,
2.INT,
3.UINT,
4.DOUBLE,
5.SIZE,
6.ENUM,
7.RANDOM
Value obtained from FuzzedDataProvider

Steps to run

  1. Build the fuzzer
  $ mm -j$(nproc) init_property_fuzzer
  1. Run on device
  $ adb sync data
  $ adb shell /data/fuzz/arm64/init_property_fuzzer/init_property_fuzzer

Fuzzer for InitUeventHandler

Maximize code coverage

The configuration parameters are not hardcoded, but instead selected based on incoming data. This ensures more code paths are reached by the fuzzer.

InitUeventHandler supports the following parameters:

  1. Major (parameter name: major)
  2. Minor (parameter name: minor)
  3. PartitionNum (parameter name: partition_num)
  4. Uid (parameter name: uid)
  5. Gid (parameter name: gid)
  6. Action (parameter name: action)
  7. Path (parameter name: path)
  8. Subsystem (parameter name: subsystem)
  9. PartitionName (parameter name: partition_name)
  10. DeviceName (parameter name: device_name)
  11. Modalias (parameter name: modalias)
  12. DevPath (parameter name: devPath)
  13. HandlerPath (parameter name: handlerPath)
Parameter Valid Values Configured Value
major UINT32_MIN to UINT32_MAX Value obtained from FuzzedDataProvider
minor UINT32_MIN to UINT32_MAX Value obtained from FuzzedDataProvider
partition_num UINT32_MIN to UINT32_MAX Value obtained from FuzzedDataProvider
uid UINT32_MIN to UINT32_MAX Value obtained from FuzzedDataProvider
gid UINT32_MIN to UINT32_MAX Value obtained from FuzzedDataProvider
action String Value obtained from FuzzedDataProvider
path String Value obtained from FuzzedDataProvider
subsystem String Value obtained from FuzzedDataProvider
partition_name String Value obtained from FuzzedDataProvider
device_name String Value obtained from FuzzedDataProvider
modalias String Value obtained from FuzzedDataProvider
devPath String Value obtained from FuzzedDataProvider
handlerPath String Value obtained from FuzzedDataProvider

This also ensures that the plugin is always deterministic for any given input.

Steps to run

  1. Build the fuzzer
$ mm -j$(nproc) init_ueventHandler_fuzzer
  1. Run on device
$ adb sync data
$ adb shell /data/fuzz/arm64/init_ueventHandler_fuzzer/init_ueventHandler_fuzzer