High level conclusions

Reachability and coverage overview

The following table shows data about each function in the project. The functions included in this table correspond to all functions that exist in the executables of the fuzzers. As such, there may be functions that are from third-party libraries.

Fuzzer: unzip_fuzzer

Call tree

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Runtime coverage analysis

Files reached

Fuzzer: zip_fuzzer

Call tree

Fuzz blockers

The following nodes represent call sites where fuzz blockers occur.

Runtime coverage analysis

Files reached

Optimal target analysis

Remaining optimal interesting functions

The following table shows a list of functions that are optimal targets. Optimal targets are identified by finding the functions that in combination, yield a high code coverage.

Implementing fuzzers that target the above functions will improve reachability such that it becomes:

All functions overview

If you implement fuzzers for these functions, the status of all functions in the project will be:

This sections provides heuristics that can be used as input to a fuzz engine when running a given fuzz target. The current focus is on providing input that is usable by libFuzzer.

test/fuzz/unzip_fuzzer.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['mz_zip_entry_read_close', 'mz_stream_close', 'mz_stream_zlib_create', 'mz_zip_entry_seek_local_header', 'mz_stream_write', 'mz_stream_read', 'mz_zip_recover_cd', 'mz_stream_wzaes_create', 'mz_stream_open']

test/fuzz/zip_fuzzer.c

Dictionary

Use this with the libFuzzer -dict=DICT.file flag

Fuzzer function priority

Use one of these functions as input to libfuzzer with flag: -focus_function name

-focus_function=['mz_stream_write', 'mz_stream_tell', 'mz_zip_entry_write_header', 'mz_stream_get_prop_int64', 'mz_stream_set_prop_int64', 'mz_zip_entry_write_open', 'mz_zip_entry_write_close', 'mz_zip_write_cd', 'mz_zip_entry_close_int']

This section shows analysis of runtime coverage data.

Complex functions with low coverage

New fuzzers

The below fuzzers are templates and suggestions for how to target the set of optimal functions above

minizip.c

#include "ada_fuzz_header.h"

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
  af_safe_gb_init(data, size);

  /* target minizip_extract */
  char *new_var0 = ada_safe_get_char_p();
  char *new_var1 = ada_safe_get_char_p();
  char *new_var2 = ada_safe_get_char_p();
  char *new_var3 = ada_safe_get_char_p();
  UNKNOWN_TYPE unknown_4;
  minizip_extract(new_var0, new_var1, new_var2, new_var3, unknown_4);

  /* target minizip_add */
  char *new_var5 = ada_safe_get_char_p();
  char *new_var6 = ada_safe_get_char_p();
  UNKNOWN_TYPE unknown_7;
  UNKNOWN_TYPE unknown_8;
  char **new_var9 = af_get_double_char_p();
  minizip_add(new_var5, new_var6, unknown_7, unknown_8, new_var9);

  /* target minizip_erase */
  char *new_var14 = ada_safe_get_char_p();
  char *new_var15 = ada_safe_get_char_p();
  UNKNOWN_TYPE unknown_16;
  char **new_var17 = af_get_double_char_p();
  minizip_erase(new_var14, new_var15, unknown_16, new_var17);

  af_safe_gb_cleanup();
}

test_compat.cc

#include "ada_fuzz_header.h"

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
  af_safe_gb_init(data, size);

  /* target test_unzip_compat */
  UNKNOWN_TYPE unknown_10;
  test_unzip_compat(unknown_10);

  af_safe_gb_cleanup();
}

mz_strm_wzaes.c

#include "ada_fuzz_header.h"

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
  af_safe_gb_init(data, size);

  /* target mz_stream_wzaes_open */
  UNKNOWN_TYPE unknown_11;
  char *new_var12 = ada_safe_get_char_p();
  UNKNOWN_TYPE unknown_13;
  mz_stream_wzaes_open(unknown_11, new_var12, unknown_13);

  af_safe_gb_cleanup();
}

minigzip.c

#include "ada_fuzz_header.h"

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
  af_safe_gb_init(data, size);

  /* target minigzip_copy */
  char *new_var18 = ada_safe_get_char_p();
  char *new_var19 = ada_safe_get_char_p();
  UNKNOWN_TYPE unknown_20;
  UNKNOWN_TYPE unknown_21;
  minigzip_copy(new_var18, new_var19, unknown_20, unknown_21);

  af_safe_gb_cleanup();
}

mz_strm_split.c

#include "ada_fuzz_header.h"

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
  af_safe_gb_init(data, size);

  /* target mz_stream_split_write */
  UNKNOWN_TYPE unknown_22;
  UNKNOWN_TYPE unknown_23;
  UNKNOWN_TYPE unknown_24;
  mz_stream_split_write(unknown_22, unknown_23, unknown_24);

  af_safe_gb_cleanup();
}

Files in report

Directories in report

This section shows a list of 3rd party function calls and their relative coverage information. By static analysis of the target project code, all of the 3rd party function call and their caller information, including the source file and line number that initiate the call are captured. The caller source code file and line number are shown in column 2 while column 1 is the function name of the 3rd party function call. Each occurrent of the 3rd party function call will occuply a separate row. Column 3 of each row indicate if the 3rd party call in the source file line is unreachable. Column 4 lists all fuzzers that have covered that particular system call in that specific location (source file and line)during their dynamic fuzzing.

Function in each files in report