diff options
| -rw-r--r-- | docs/Changelog.md | 4 | ||||
| -rw-r--r-- | include/afl-fuzz.h | 14 | ||||
| -rw-r--r-- | src/afl-fuzz-init.c | 8 | ||||
| -rw-r--r-- | src/afl-fuzz-one.c | 10 | ||||
| -rw-r--r-- | src/afl-fuzz-queue.c | 124 | ||||
| -rw-r--r-- | src/afl-fuzz.c | 100 |
6 files changed, 227 insertions, 33 deletions
diff --git a/docs/Changelog.md b/docs/Changelog.md index 9eb47e18..f15f1d93 100644 --- a/docs/Changelog.md +++ b/docs/Changelog.md @@ -17,6 +17,10 @@ sending a mail to <afl-users+subscribe@googlegroups.com>. - memory limits are now disabled by default, set them with -m if required - deterministic fuzzing is now disabled by default and can be enabled with -D. It is still enabled by default for -M. + - a new seed selection was implemented that uses weighted randoms based on + a schedule performance score, which is much better that the previous + walk the whole queue approach. Select the old mode with -Z (auto enabled + with -M) - statsd support by Edznux, thanks a lot! - Marcel Boehme submitted a patch that improves all AFFast schedules :) - reading testcases from -i now descends into subdirectories diff --git a/include/afl-fuzz.h b/include/afl-fuzz.h index e9d148e9..45de197d 100644 --- a/include/afl-fuzz.h +++ b/include/afl-fuzz.h @@ -151,7 +151,8 @@ struct queue_entry { favored, /* Currently favored? */ fs_redundant, /* Marked as redundant in the fs? */ fully_colorized, /* Do not run redqueen stage again */ - is_ascii; /* Is the input just ascii text? */ + is_ascii, /* Is the input just ascii text? */ + disabled; /* Is disabled from fuzz selection */ u32 bitmap_size, /* Number of bits set in bitmap */ fuzz_level, /* Number of fuzzing iterations */ @@ -165,6 +166,8 @@ struct queue_entry { u8 *trace_mini; /* Trace bytes, if kept */ u32 tc_ref; /* Trace bytes ref count */ + double perf_score; /* performance score */ + struct queue_entry *next; /* Next element, if any */ }; @@ -488,12 +491,17 @@ typedef struct afl_state { disable_trim, /* Never trim in fuzz_one */ shmem_testcase_mode, /* If sharedmem testcases are used */ expand_havoc, /* perform expensive havoc after no find */ - cycle_schedules; /* cycle power schedules? */ + cycle_schedules, /* cycle power schedules? */ + old_seed_selection; /* use vanilla afl seed selection */ u8 *virgin_bits, /* Regions yet untouched by fuzzing */ *virgin_tmout, /* Bits we haven't seen in tmouts */ *virgin_crash; /* Bits we haven't seen in crashes */ + double *alias_probability; /* alias weighted probabilities */ + u32 * alias_table; /* alias weighted random lookup table */ + u32 active_paths; /* enabled entries in the queue */ + u8 *var_bytes; /* Bytes that appear to be variable */ #define N_FUZZ_SIZE (1 << 21) @@ -1009,6 +1017,8 @@ void find_timeout(afl_state_t *); double get_runnable_processes(void); void nuke_resume_dir(afl_state_t *); int check_main_node_exists(afl_state_t *); +u32 select_next_queue_entry(afl_state_t *afl); +void create_alias_table(afl_state_t *afl); void setup_dirs_fds(afl_state_t *); void setup_cmdline_file(afl_state_t *, char **); void setup_stdio_file(afl_state_t *); diff --git a/src/afl-fuzz-init.c b/src/afl-fuzz-init.c index 65478a78..881bf10f 100644 --- a/src/afl-fuzz-init.c +++ b/src/afl-fuzz-init.c @@ -959,6 +959,8 @@ void perform_dry_run(afl_state_t *afl) { /* Remove from fuzzing queue but keep for splicing */ struct queue_entry *p = afl->queue; + p->disabled = 1; + p->perf_score = 0; while (p && p->next != q) p = p->next; @@ -968,6 +970,7 @@ void perform_dry_run(afl_state_t *afl) { afl->queue = q->next; --afl->pending_not_fuzzed; + --afl->active_paths; afl->max_depth = 0; p = afl->queue; @@ -1054,6 +1057,7 @@ restart_outer_cull_loop: duplicates = 1; --afl->pending_not_fuzzed; + afl->active_paths--; // We do not remove any of the memory allocated because for // splicing the data might still be interesting. @@ -1063,11 +1067,15 @@ restart_outer_cull_loop: // we keep the shorter file if (p->len >= q->len) { + p->disabled = 1; + p->perf_score = 0; q->next = p->next; goto restart_inner_cull_loop; } else { + q->disabled = 1; + q->perf_score = 0; if (prev) prev->next = q = p; else diff --git a/src/afl-fuzz-one.c b/src/afl-fuzz-one.c index c04b492b..6ef728e0 100644 --- a/src/afl-fuzz-one.c +++ b/src/afl-fuzz-one.c @@ -554,7 +554,10 @@ u8 fuzz_one_original(afl_state_t *afl) { * PERFORMANCE SCORE * *********************/ - orig_perf = perf_score = calculate_score(afl, afl->queue_cur); + if (likely(!afl->old_seed_selection)) + orig_perf = perf_score = afl->queue_cur->perf_score; + else + orig_perf = perf_score = calculate_score(afl, afl->queue_cur); if (unlikely(perf_score == 0)) { goto abandon_entry; } @@ -2769,7 +2772,10 @@ static u8 mopt_common_fuzzing(afl_state_t *afl, MOpt_globals_t MOpt_globals) { * PERFORMANCE SCORE * *********************/ - orig_perf = perf_score = calculate_score(afl, afl->queue_cur); + if (likely(!afl->old_seed_selection)) + orig_perf = perf_score = afl->queue_cur->perf_score; + else + orig_perf = perf_score = calculate_score(afl, afl->queue_cur); if (unlikely(afl->shm.cmplog_mode && !afl->queue_cur->fully_colorized)) { diff --git a/src/afl-fuzz-queue.c b/src/afl-fuzz-queue.c index 0d7d0314..d608e890 100644 --- a/src/afl-fuzz-queue.c +++ b/src/afl-fuzz-queue.c @@ -27,6 +27,129 @@ #include <ctype.h> #include <math.h> +inline u32 select_next_queue_entry(afl_state_t *afl) { + + u32 r = rand_below(afl, 0xffffffff); + u32 s = r % afl->queued_paths; + // fprintf(stderr, "select: r=%u s=%u ... r < prob[s]=%f ? s=%u : + // alias[%u]=%u\n", r, s, afl->alias_probability[s], s, s, + // afl->alias_table[s]); + return (r < afl->alias_probability[s] ? s : afl->alias_table[s]); + +} + +void create_alias_table(afl_state_t *afl) { + + u32 n = afl->queued_paths, i = 0, a, g; + + afl->alias_table = + (u32 *)afl_realloc((void **)&afl->alias_table, n * sizeof(u32)); + afl->alias_probability = (double *)afl_realloc( + (void **)&afl->alias_probability, n * sizeof(double)); + double *P = (double *)afl_realloc(AFL_BUF_PARAM(out), n * sizeof(double)); + int * S = (u32 *)afl_realloc(AFL_BUF_PARAM(out_scratch), n * sizeof(u32)); + int * L = (u32 *)afl_realloc(AFL_BUF_PARAM(in_scratch), n * sizeof(u32)); + + if (!P || !S || !L) FATAL("could not aquire memory for alias table"); + memset((void *)afl->alias_table, 0, n * sizeof(u32)); + memset((void *)afl->alias_probability, 0, n * sizeof(double)); + + double sum = 0; + + for (i = 0; i < n; i++) { + + struct queue_entry *q = afl->queue_buf[i]; + + if (!q->disabled) q->perf_score = calculate_score(afl, q); + + sum += q->perf_score; + /* + if (afl->debug) + fprintf(stderr, "entry %u: score=%f %s (sum: %f)\n", i, q->perf_score, + q->disabled ? "disabled" : "", sum); + */ + + } + + for (i = 0; i < n; i++) { + + struct queue_entry *q = afl->queue_buf[i]; + + P[i] = q->perf_score * n / sum; + + } + + int nS = 0, nL = 0, s; + for (s = (s32)n - 1; s >= 0; --s) { + + if (P[s] < 1) + S[nS++] = s; + else + L[nL++] = s; + + } + + while (nS && nL) { + + a = S[--nS]; + g = L[--nL]; + afl->alias_probability[a] = P[a]; + afl->alias_table[a] = g; + P[g] = P[g] + P[a] - 1; + if (P[g] < 1) + S[nS++] = g; + else + L[nL++] = g; + + } + + while (nL) + afl->alias_probability[L[--nL]] = 1; + + while (nS) + afl->alias_probability[S[--nS]] = 1; + + /* + if (afl->debug) { + + fprintf(stderr, " %-3s %-3s %-9s\n", "entry", "alias", "prob"); + for (u32 i = 0; i < n; ++i) + fprintf(stderr, " %3i %3i %9.7f\n", i, afl->alias_table[i], + afl->alias_probability[i]); + + } + + int prob = 0; + fprintf(stderr, "Alias:"); + for (i = 0; i < n; i++) { + + fprintf(stderr, " [%u]=%u", i, afl->alias_table[i]); + if (afl->alias_table[i] >= n) + prob = i; + + } + + fprintf(stderr, "\n"); + + if (prob) { + + fprintf(stderr, "PROBLEM! alias[%u] = %u\n", prob, + afl->alias_table[prob]); + + for (i = 0; i < n; i++) { + + struct queue_entry *q = afl->queue_buf[i]; + + fprintf(stderr, "%u: score=%f\n", i, q->perf_score); + + } + + } + + */ + +} + /* Mark deterministic checks as done for a particular queue entry. We use the .state file to avoid repeating deterministic fuzzing when resuming aborted scans. */ @@ -237,6 +360,7 @@ void add_to_queue(afl_state_t *afl, u8 *fname, u32 len, u8 passed_det) { if (likely(q->len > 4)) afl->ready_for_splicing_count++; ++afl->queued_paths; + ++afl->active_paths; ++afl->pending_not_fuzzed; afl->cycles_wo_finds = 0; diff --git a/src/afl-fuzz.c b/src/afl-fuzz.c index 24df2997..004adffe 100644 --- a/src/afl-fuzz.c +++ b/src/afl-fuzz.c @@ -115,6 +115,8 @@ static void usage(u8 *argv0, int more_help) { " if using QEMU, just use -c 0.\n\n" "Fuzzing behavior settings:\n" + " -Z - sequential queue selection instead of weighted " + "random\n" " -N - do not unlink the fuzzing input file (for devices " "etc.)\n" " -n - fuzz without instrumentation (non-instrumented mode)\n" @@ -131,8 +133,7 @@ static void usage(u8 *argv0, int more_help) { "Other stuff:\n" " -M/-S id - distributed mode (see docs/parallel_fuzzing.md)\n" - " use -D to force -S secondary to perform deterministic " - "fuzzing\n" + " -M auto-sets -D and -Z (use -d to disable -D)\n" " -F path - sync to a foreign fuzzer queue directory (requires " "-M, can\n" " be specified up to %u times)\n" @@ -250,7 +251,7 @@ int main(int argc, char **argv_orig, char **envp) { s32 opt, i; u64 prev_queued = 0; - u32 sync_interval_cnt = 0, seek_to, show_help = 0, map_size = MAP_SIZE; + u32 sync_interval_cnt = 0, seek_to = 0, show_help = 0, map_size = MAP_SIZE; u8 *extras_dir[4]; u8 mem_limit_given = 0, exit_1 = 0, debug = 0, extras_dir_cnt = 0 /*, have_p = 0*/; @@ -287,10 +288,14 @@ int main(int argc, char **argv_orig, char **envp) { while ((opt = getopt( argc, argv, - "+b:c:i:I:o:f:F:m:t:T:dDnCB:S:M:x:QNUWe:p:s:V:E:L:hRP:")) > 0) { + "+b:c:i:I:o:f:F:m:t:T:dDnCB:S:M:x:QNUWe:p:s:V:E:L:hRP:Z")) > 0) { switch (opt) { + case 'Z': + afl->old_seed_selection = 1; + break; + case 'I': afl->infoexec = optarg; break; @@ -355,14 +360,16 @@ int main(int argc, char **argv_orig, char **envp) { afl->schedule = RARE; - } else if (!stricmp(optarg, "explore") || !stricmp(optarg, "afl")) { - - afl->schedule = EXPLORE; + } else if (!stricmp(optarg, "explore") || !stricmp(optarg, "afl") || - } else if (!stricmp(optarg, "seek") || !stricmp(optarg, "default") || + !stricmp(optarg, "default") || !stricmp(optarg, "normal")) { + afl->schedule = EXPLORE; + + } else if (!stricmp(optarg, "seek")) { + afl->schedule = SEEK; } else { @@ -404,7 +411,8 @@ int main(int argc, char **argv_orig, char **envp) { if (afl->sync_id) { FATAL("Multiple -S or -M options not supported"); } afl->sync_id = ck_strdup(optarg); - afl->skip_deterministic = 0; + afl->skip_deterministic = 0; // force determinsitic fuzzing + afl->old_seed_selection = 1; // force old queue walking seed selection if ((c = strchr(afl->sync_id, ':'))) { @@ -1131,8 +1139,10 @@ int main(int argc, char **argv_orig, char **envp) { if (afl->is_secondary_node && check_main_node_exists(afl) == 0) { - WARNF("no -M main node found. You need to run one main instance!"); - sleep(3); + WARNF( + "no -M main node found. It is recommended to run exactly one main " + "instance."); + sleep(1); } @@ -1302,7 +1312,7 @@ int main(int argc, char **argv_orig, char **envp) { show_init_stats(afl); - seek_to = find_start_position(afl); + if (unlikely(afl->old_seed_selection)) seek_to = find_start_position(afl); write_stats_file(afl, 0, 0, 0); maybe_update_plot_file(afl, 0, 0); @@ -1324,28 +1334,37 @@ int main(int argc, char **argv_orig, char **envp) { // real start time, we reset, so this works correctly with -V afl->start_time = get_cur_time(); + u32 runs_in_current_cycle = (u32)-1; + u32 prev_queued_paths = 0; + while (1) { u8 skipped_fuzz; cull_queue(afl); - if (!afl->queue_cur) { + if (unlikely((!afl->old_seed_selection && + runs_in_current_cycle > afl->queued_paths) || + (afl->old_seed_selection && !afl->queue_cur))) { ++afl->queue_cycle; - afl->current_entry = 0; + runs_in_current_cycle = 0; afl->cur_skipped_paths = 0; - afl->queue_cur = afl->queue; - if (seek_to) { + if (unlikely(afl->old_seed_selection)) { - afl->current_entry = seek_to; - afl->queue_cur = afl->queue_buf[seek_to]; - seek_to = 0; + afl->current_entry = 0; + afl->queue_cur = afl->queue; - } + if (unlikely(seek_to)) { - // show_stats(afl); + afl->current_entry = seek_to; + afl->queue_cur = afl->queue_buf[seek_to]; + seek_to = 0; + + } + + } if (unlikely(afl->not_on_tty)) { @@ -1366,9 +1385,11 @@ int main(int argc, char **argv_orig, char **envp) { switch (afl->expand_havoc) { case 0: + // this adds extra splicing mutation options to havoc mode afl->expand_havoc = 1; break; case 1: + // add MOpt mutator if (afl->limit_time_sig == 0 && !afl->custom_only && !afl->python_only) { @@ -1381,25 +1402,26 @@ int main(int argc, char **argv_orig, char **envp) { break; case 2: // if (!have_p) afl->schedule = EXPLOIT; + // increase havoc mutations per fuzz attempt afl->havoc_stack_pow2++; afl->expand_havoc = 3; break; case 3: + // further increase havoc mutations per fuzz attempt afl->havoc_stack_pow2++; afl->expand_havoc = 4; break; case 4: + // if not in sync mode, enable deterministic mode? + // if (!afl->sync_dir) afl->skip_deterministic = 0; + afl->expand_havoc = 5; + break; + case 5: // nothing else currently break; } - if (afl->expand_havoc) { - - } else - - afl->expand_havoc = 1; - } else { afl->use_splicing = 1; @@ -1470,6 +1492,22 @@ int main(int argc, char **argv_orig, char **envp) { } + if (likely(!afl->old_seed_selection)) { + + ++runs_in_current_cycle; + if (unlikely(prev_queued_paths < afl->queued_paths)) { + + // we have new queue entries since the last run, recreate alias table + prev_queued_paths = afl->queued_paths; + create_alias_table(afl); + + } + + afl->current_entry = select_next_queue_entry(afl); + afl->queue_cur = afl->queue_buf[afl->current_entry]; + + } + skipped_fuzz = fuzz_one(afl); if (!skipped_fuzz && !afl->stop_soon && afl->sync_id) { @@ -1490,8 +1528,12 @@ int main(int argc, char **argv_orig, char **envp) { if (afl->stop_soon) { break; } - afl->queue_cur = afl->queue_cur->next; - ++afl->current_entry; + if (unlikely(afl->old_seed_selection)) { + + afl->queue_cur = afl->queue_cur->next; + ++afl->current_entry; + + } } |