diff options
| -rw-r--r-- | custom_mutators/autotokens/Makefile | 6 | ||||
| -rw-r--r-- | custom_mutators/autotokens/autotokens.cpp | 103 | ||||
| -rw-r--r-- | docs/custom_mutators.md | 11 | ||||
| -rw-r--r-- | include/afl-fuzz.h | 14 | ||||
| -rw-r--r-- | src/afl-fuzz-mutators.c | 13 | ||||
| -rw-r--r-- | src/afl-fuzz-one.c | 3 | ||||
| -rw-r--r-- | src/afl-fuzz-python.c | 16 |
7 files changed, 155 insertions, 11 deletions
diff --git a/custom_mutators/autotokens/Makefile b/custom_mutators/autotokens/Makefile index 8af63635..ab1da4b6 100644 --- a/custom_mutators/autotokens/Makefile +++ b/custom_mutators/autotokens/Makefile @@ -1,5 +1,9 @@ ifdef debug - CFLAGS += "-fsanitize=address -Wall" + CFLAGS += -fsanitize=address -Wall + CXX := clang++ +endif +ifdef DEBUG + CFLAGS += -fsanitize=address -Wall CXX := clang++ endif diff --git a/custom_mutators/autotokens/autotokens.cpp b/custom_mutators/autotokens/autotokens.cpp index 7aecb010..c9ec4352 100644 --- a/custom_mutators/autotokens/autotokens.cpp +++ b/custom_mutators/autotokens/autotokens.cpp @@ -19,6 +19,13 @@ extern "C" { #define AUTOTOKENS_ALTERNATIVE_TOKENIZE 0 #define AUTOTOKENS_CHANGE_MIN 8 #define AUTOTOKENS_WHITESPACE " " +#define AUTOTOKENS_SIZE_MIN 8 +#define AUTOTOKENS_SPLICE_MIN 4 +#define AUTOTOKENS_SPLICE_MAX 64 + +#if AUTOTOKENS_SPLICE_MIN >= AUTOTOKENS_SIZE_MIN + #error SPLICE_MIN must be lower than SIZE_MIN +#endif using namespace std; @@ -42,6 +49,7 @@ static u32 extras_cnt, a_extras_cnt; static u64 all_spaces, all_tabs, all_lf, all_ws; static u64 all_structure_items; static unordered_map<string, vector<u32> *> file_mapping; +static unordered_map<u32, vector<u32> *> id_mapping; static unordered_map<string, u32> token_to_id; static unordered_map<u32, string> id_to_token; static string whitespace = AUTOTOKENS_WHITESPACE; @@ -76,6 +84,8 @@ extern "C" size_t afl_custom_fuzz(my_mutator_t *data, u8 *buf, size_t buf_size, u8 **out_buf, u8 *add_buf, size_t add_buf_size, size_t max_size) { + (void)(data); + if (s == NULL) { *out_buf = NULL; @@ -92,14 +102,14 @@ extern "C" size_t afl_custom_fuzz(my_mutator_t *data, u8 *buf, size_t buf_size, afl_ptr->havoc_div / 256)); // DEBUG(stderr, "structure size: %lu, rounds: %u \n", m.size(), rounds); - u32 max_rand = 7; + u32 max_rand = 14; for (i = 0; i < rounds; ++i) { switch (rand_below(afl_ptr, max_rand)) { /* CHANGE */ - case 0 ... 3: /* fall through */ + case 0 ... 7: /* fall through */ { u32 pos = rand_below(afl_ptr, m_size); @@ -122,18 +132,19 @@ extern "C" size_t afl_custom_fuzz(my_mutator_t *data, u8 *buf, size_t buf_size, } /* INSERT (m_size +1 so we insert also after last place) */ - case 4 ... 5: { + case 8 ... 9: { u32 new_item; do { new_item = rand_below(afl_ptr, current_id); - } while (!alternative_tokenize && new_item >= whitespace_ids); + } while (unlikely(!alternative_tokenize && new_item >= whitespace_ids)); u32 pos = rand_below(afl_ptr, m_size + 1); m.insert(m.begin() + pos, new_item); ++m_size; + DEBUG(stderr, "INS: %u at %u\n", new_item, pos); if (likely(!alternative_tokenize)) { @@ -168,8 +179,63 @@ extern "C" size_t afl_custom_fuzz(my_mutator_t *data, u8 *buf, size_t buf_size, } + /* SPLICING */ + case 10 ... 11: { + + u32 strategy = rand_below(afl_ptr, 4), dst_off, n; + auto src = id_mapping[rand_below(afl_ptr, valid_structures)]; + u32 src_size = src->size(); + u32 src_off = rand_below(afl_ptr, src_size - AUTOTOKENS_SPLICE_MIN); + u32 rand_r = 1 + MAX(AUTOTOKENS_SPLICE_MIN, + MIN(AUTOTOKENS_SPLICE_MAX, src_size - src_off)); + + switch (strategy) { + + // insert + case 0: { + + dst_off = rand_below(afl_ptr, m_size); + n = AUTOTOKENS_SPLICE_MIN + + rand_below(afl_ptr, MIN(AUTOTOKENS_SPLICE_MAX, + rand_r - AUTOTOKENS_SPLICE_MIN)); + m.insert(m.begin() + dst_off, src->begin() + src_off, + src->begin() + src_off + n); + m_size += n; + DEBUG(stderr, "SPLICE-INS: %u at %u\n", n, dst_off); + break; + + } + + // overwrite + default: { + + dst_off = rand_below(afl_ptr, m_size - AUTOTOKENS_SPLICE_MIN); + n = AUTOTOKENS_SPLICE_MIN + + rand_below( + afl_ptr, + MIN(AUTOTOKENS_SPLICE_MAX - AUTOTOKENS_SPLICE_MIN, + MIN(m_size - dst_off - AUTOTOKENS_SPLICE_MIN, + src_size - src_off - AUTOTOKENS_SPLICE_MIN))); + + for (u32 i = 0; i < n; ++i) { + + m[dst_off + i] = (*src)[src_off + i]; + + } + + DEBUG(stderr, "SPLICE-MUT: %u at %u\n", n, dst_off); + break; + + } + + } + + break; + + } + /* ERASE - only if large enough */ - case 6: { + case 12 ... 13: { if (m_size > 8) { @@ -178,7 +244,7 @@ extern "C" size_t afl_custom_fuzz(my_mutator_t *data, u8 *buf, size_t buf_size, } else { - max_rand = 6; + max_rand = 12; } @@ -236,12 +302,15 @@ extern "C" size_t afl_custom_fuzz(my_mutator_t *data, u8 *buf, size_t buf_size, extern "C" unsigned char afl_custom_queue_get(void *data, const unsigned char *filename) { + (void)(data); + if (likely(!debug)) { if ((afl_ptr->shm.cmplog_mode && !afl_ptr->queue_cur->is_ascii) || (only_fav && !afl_ptr->queue_cur->favored)) { s = NULL; + DEBUG(stderr, "cmplog not ascii or only_fav and not favorite\n"); return 0; } @@ -334,8 +403,8 @@ extern "C" unsigned char afl_custom_queue_get(void *data, fclose(fp); file_mapping[fn] = structure; // NULL ptr so we don't read the file again - DEBUG(stderr, "Too short (%lu) %s\n", len, filename); s = NULL; + DEBUG(stderr, "Too short (%lu) %s\n", len, filename); return 0; } @@ -362,8 +431,8 @@ extern "C" unsigned char afl_custom_queue_get(void *data, if (((len * AFL_TXT_MIN_PERCENT) / 100) > valid_chars) { file_mapping[fn] = NULL; - DEBUG(stderr, "Not text (%lu) %s\n", len, filename); s = NULL; + DEBUG(stderr, "Not text (%lu) %s\n", len, filename); return 0; } @@ -766,6 +835,15 @@ extern "C" unsigned char afl_custom_queue_get(void *data, } + if (tokens.size() < AUTOTOKENS_SIZE_MIN) { + + file_mapping[fn] = NULL; + s = NULL; + DEBUG(stderr, "too few tokens\n"); + return 0; + + } + /* Now we transform the tokens into an ID list and saved that */ structure = new vector<u32>(); @@ -791,8 +869,9 @@ extern "C" unsigned char afl_custom_queue_get(void *data, // save the token structure to the file mapping file_mapping[fn] = structure; - s = structure; + id_mapping[valid_structures] = structure; ++valid_structures; + s = structure; all_structure_items += structure->size(); // we are done! @@ -897,6 +976,12 @@ extern "C" my_mutator_t *afl_custom_init(afl_state *afl, unsigned int seed) { } +extern "C" void afl_custom_splice_optout(my_mutator_t *data) { + + (void)(data); + +} + extern "C" void afl_custom_deinit(my_mutator_t *data) { /* we use this to print statistics at exit :-) diff --git a/docs/custom_mutators.md b/docs/custom_mutators.md index 4ffeda7a..322caa5b 100644 --- a/docs/custom_mutators.md +++ b/docs/custom_mutators.md @@ -48,6 +48,7 @@ C/C++: ```c void *afl_custom_init(afl_state_t *afl, unsigned int seed); unsigned int afl_custom_fuzz_count(void *data, const unsigned char *buf, size_t buf_size); +void afl_custom_splice_optout(void *data); size_t afl_custom_fuzz(void *data, unsigned char *buf, size_t buf_size, unsigned char **out_buf, unsigned char *add_buf, size_t add_buf_size, size_t max_size); const char *afl_custom_describe(void *data, size_t max_description_len); size_t afl_custom_post_process(void *data, unsigned char *buf, size_t buf_size, unsigned char **out_buf); @@ -72,6 +73,9 @@ def init(seed): def fuzz_count(buf): return cnt +def splice_optout() + pass + def fuzz(buf, add_buf, max_size): return mutated_out @@ -132,6 +136,13 @@ def deinit(): # optional for Python for a specific queue entry, use this function. This function is most useful if `AFL_CUSTOM_MUTATOR_ONLY` is **not** used. +- `splice_optout` (optional): + + If this function is present, no splicing target is passed to the `fuzz` + function. This saves time if splicing data is not needed by the custom + fuzzing function. + This function is never called, just needs to be present to activate. + - `fuzz` (optional): This method performs custom mutations on a given input. It also accepts an diff --git a/include/afl-fuzz.h b/include/afl-fuzz.h index 69fea579..1e8d085d 100644 --- a/include/afl-fuzz.h +++ b/include/afl-fuzz.h @@ -344,6 +344,7 @@ enum { /* 12 */ PY_FUNC_INTROSPECTION, /* 13 */ PY_FUNC_DESCRIBE, /* 14 */ PY_FUNC_FUZZ_SEND, + /* 15 */ PY_FUNC_SPLICE_OPTOUT, PY_FUNC_COUNT }; @@ -495,6 +496,7 @@ typedef struct afl_state { no_unlink, /* do not unlink cur_input */ debug, /* Debug mode */ custom_only, /* Custom mutator only mode */ + custom_splice_optout, /* Custom mutator no splice buffer */ is_main_node, /* if this is the main node */ is_secondary_node, /* if this is a secondary instance */ pizza_is_served; /* pizza mode */ @@ -829,6 +831,17 @@ struct custom_mutator { u32 (*afl_custom_fuzz_count)(void *data, const u8 *buf, size_t buf_size); /** + * Opt-out of a splicing input for the fuzz mutator + * + * Empty dummy function. It's presence tells afl-fuzz not to pass a + * splice data pointer and len. + * + * @param data pointer returned in afl_custom_init by this custom mutator + * @noreturn + */ + void (*afl_custom_splice_optout)(void *data); + + /** * Perform custom mutations on a given input * * (Optional for now. Required in the future) @@ -1057,6 +1070,7 @@ u8 havoc_mutation_probability_py(void *); u8 queue_get_py(void *, const u8 *); const char *introspection_py(void *); u8 queue_new_entry_py(void *, const u8 *, const u8 *); +void splice_optout(void *); void deinit_py(void *); #endif diff --git a/src/afl-fuzz-mutators.c b/src/afl-fuzz-mutators.c index 22e5262e..ce43064a 100644 --- a/src/afl-fuzz-mutators.c +++ b/src/afl-fuzz-mutators.c @@ -358,6 +358,19 @@ struct custom_mutator *load_custom_mutator(afl_state_t *afl, const char *fn) { } + /* "afl_custom_splice_optout", optional, never called */ + mutator->afl_custom_splice_optout = dlsym(dh, "afl_custom_splice_optout"); + if (!mutator->afl_custom_splice_optout) { + + ACTF("optional symbol 'afl_custom_splice_optout' not found."); + + } else { + + OKF("Found 'afl_custom_splice_optout'."); + afl->custom_splice_optout = 1; + + } + /* "afl_custom_fuzz_send", optional */ mutator->afl_custom_fuzz_send = dlsym(dh, "afl_custom_fuzz_send"); if (!mutator->afl_custom_fuzz_send) { diff --git a/src/afl-fuzz-one.c b/src/afl-fuzz-one.c index eaf65987..5e352dcb 100644 --- a/src/afl-fuzz-one.c +++ b/src/afl-fuzz-one.c @@ -1954,7 +1954,8 @@ custom_mutator_stage: u32 target_len = 0; /* check if splicing makes sense yet (enough entries) */ - if (likely(afl->ready_for_splicing_count > 1)) { + if (likely(!afl->custom_splice_optout && + afl->ready_for_splicing_count > 1)) { /* Pick a random other queue entry for passing to external API that has the necessary length */ diff --git a/src/afl-fuzz-python.c b/src/afl-fuzz-python.c index b509b936..69c305f7 100644 --- a/src/afl-fuzz-python.c +++ b/src/afl-fuzz-python.c @@ -248,6 +248,8 @@ static py_mutator_t *init_py_module(afl_state_t *afl, u8 *module_name) { PyObject_GetAttrString(py_module, "queue_get"); py_functions[PY_FUNC_FUZZ_SEND] = PyObject_GetAttrString(py_module, "fuzz_send"); + py_functions[PY_FUNC_SPLICE_OPTOUT] = + PyObject_GetAttrString(py_module, "splice_optout"); py_functions[PY_FUNC_QUEUE_NEW_ENTRY] = PyObject_GetAttrString(py_module, "queue_new_entry"); py_functions[PY_FUNC_INTROSPECTION] = @@ -394,6 +396,13 @@ void deinit_py(void *py_mutator) { } +void splice_optout_py(void *py_mutator) { + + // this is never called + (void)(py_mutator); + +} + struct custom_mutator *load_custom_mutator_py(afl_state_t *afl, char *module_name) { @@ -474,6 +483,13 @@ struct custom_mutator *load_custom_mutator_py(afl_state_t *afl, } + if (py_functions[PY_FUNC_SPLICE_OPTOUT]) { + + mutator->afl_custom_splice_optout = splice_optout_py; + afl->custom_splice_optout = 1; + + } + if (py_functions[PY_FUNC_QUEUE_NEW_ENTRY]) { mutator->afl_custom_queue_new_entry = queue_new_entry_py; |