diff options
| -rw-r--r-- | docs/Changelog.md | 1 | ||||
| -rw-r--r-- | docs/custom_mutators.md | 9 | ||||
| -rw-r--r-- | include/afl-fuzz.h | 9 | ||||
| -rw-r--r-- | src/afl-fuzz-python.c | 49 | ||||
| -rw-r--r-- | src/afl-fuzz-run.c | 7 |
5 files changed, 30 insertions, 45 deletions
diff --git a/docs/Changelog.md b/docs/Changelog.md index 501300b1..9436fc9f 100644 --- a/docs/Changelog.md +++ b/docs/Changelog.md @@ -13,6 +13,7 @@ everyone who was affected! - allow pizza mode to be disabled when AFL_PIZZA_MODE is set to -1 - option `-p mmopt` now also selects new queue items more often + - fix bug in post_process custom mutator implementation - print name of custom mutator in UI - afl-cc: - add CFI sanitizer variant to gcc targets diff --git a/docs/custom_mutators.md b/docs/custom_mutators.md index 82131c92..a1de479e 100644 --- a/docs/custom_mutators.md +++ b/docs/custom_mutators.md @@ -118,7 +118,7 @@ def deinit(): # optional for Python ### Custom Mutation -- `init`: +- `init` (optional in Python): This method is called when AFL++ starts up and is used to seed RNG and set up buffers and state. @@ -184,6 +184,11 @@ def deinit(): # optional for Python to the target, e.g. if it is too short, too corrupted, etc. If so, return a NULL buffer and zero length (or a 0 length string in Python). + NOTE: Do not make any random changes to the data in this function! + + PERFORMANCE for C/C++: If possible make the changes in-place (so modify + the `*data` directly, and return it as `*outbuf = data`. + - `fuzz_send` (optional): This method can be used if you want to send data to the target yourself, @@ -202,7 +207,7 @@ def deinit(): # optional for Python discovered if compiled with INTROSPECTION. The custom mutator can then return a string (const char *) that reports the exact mutations used. -- `deinit`: +- `deinit` (optional in Python): The last method to be called, deinitializing the state. diff --git a/include/afl-fuzz.h b/include/afl-fuzz.h index 5fd393dd..8b6502b4 100644 --- a/include/afl-fuzz.h +++ b/include/afl-fuzz.h @@ -885,14 +885,19 @@ struct custom_mutator { * A post-processing function to use right before AFL writes the test case to * disk in order to execute the target. * - * (Optional) If this functionality is not needed, simply don't define this + * NOTE: Do not do any random changes to the data in this function! + * + * PERFORMANCE: If you can modify the data in-place you will have a better + * performance. Modify *data and set `*out_buf = data`. + * + * (Optional) If this functionality is not needed, simply do not define this * function. * * @param[in] data pointer returned in afl_custom_init by this custom mutator * @param[in] buf Buffer containing the test case to be executed * @param[in] buf_size Size of the test case * @param[out] out_buf Pointer to the buffer storing the test case after - * processing. External library should allocate memory for out_buf. + * processing. The external library should allocate memory for out_buf. * It can chose to alter buf in-place, if the space is large enough. * @return Size of the output buffer. */ diff --git a/src/afl-fuzz-python.c b/src/afl-fuzz-python.c index 673e5a6c..7dad0770 100644 --- a/src/afl-fuzz-python.c +++ b/src/afl-fuzz-python.c @@ -219,11 +219,14 @@ static py_mutator_t *init_py_module(afl_state_t *afl, u8 *module_name) { if (py_module != NULL) { - u8 py_notrim = 0, py_idx; - /* init, required */ + u8 py_notrim = 0; py_functions[PY_FUNC_INIT] = PyObject_GetAttrString(py_module, "init"); - if (!py_functions[PY_FUNC_INIT]) - FATAL("init function not found in python module"); + if (!py_functions[PY_FUNC_INIT]) { + + WARNF("init function not found in python module"); + + } + py_functions[PY_FUNC_FUZZ] = PyObject_GetAttrString(py_module, "fuzz"); if (!py_functions[PY_FUNC_FUZZ]) py_functions[PY_FUNC_FUZZ] = PyObject_GetAttrString(py_module, "mutate"); @@ -231,12 +234,6 @@ static py_mutator_t *init_py_module(afl_state_t *afl, u8 *module_name) { PyObject_GetAttrString(py_module, "describe"); py_functions[PY_FUNC_FUZZ_COUNT] = PyObject_GetAttrString(py_module, "fuzz_count"); - if (!py_functions[PY_FUNC_FUZZ]) { - - WARNF("fuzz function not found in python module"); - - } - py_functions[PY_FUNC_POST_PROCESS] = PyObject_GetAttrString(py_module, "post_process"); py_functions[PY_FUNC_INIT_TRIM] = @@ -263,36 +260,6 @@ static py_mutator_t *init_py_module(afl_state_t *afl, u8 *module_name) { if (!py_functions[PY_FUNC_DEINIT]) WARNF("deinit function not found in python module"); - for (py_idx = 0; py_idx < PY_FUNC_COUNT; ++py_idx) { - - if (!py_functions[py_idx] || !PyCallable_Check(py_functions[py_idx])) { - - if (py_idx >= PY_FUNC_INIT_TRIM && py_idx <= PY_FUNC_TRIM) { - - // Implementing the trim API is optional for now - if (PyErr_Occurred()) { PyErr_Print(); } - py_notrim = 1; - - } else if (py_idx >= PY_OPTIONAL) { - - // Only _init and _deinit are not optional currently - - if (PyErr_Occurred()) { PyErr_Print(); } - - } else { - - fprintf(stderr, - "Cannot find/call function with index %d in external " - "Python module.\n", - py_idx); - return NULL; - - } - - } - - } - if (py_notrim) { py_functions[PY_FUNC_INIT_TRIM] = NULL; @@ -345,6 +312,8 @@ static void init_py(afl_state_t *afl, py_mutator_t *py_mutator, (void)afl; + if (py_mutator->py_functions[PY_FUNC_INIT] == NULL) { return; } + PyObject *py_args, *py_value; /* Provide the init function a seed for the Python RNG */ diff --git a/src/afl-fuzz-run.c b/src/afl-fuzz-run.c index f5425011..26e8549d 100644 --- a/src/afl-fuzz-run.c +++ b/src/afl-fuzz-run.c @@ -133,7 +133,12 @@ write_to_testcase(afl_state_t *afl, void **mem, u32 len, u32 fix) { } - if (new_mem != *mem) { *mem = new_mem; } + if (new_mem != *mem && new_mem != NULL && new_size > 0) { + + *mem = afl_realloc((void **)mem, new_size); + memmove(*mem, new_mem, new_size); + + } if (unlikely(afl->custom_mutators_count)) { |