diff options
Diffstat (limited to 'src/afl-fuzz-one.c')
| -rw-r--r-- | src/afl-fuzz-one.c | 250 |
1 files changed, 184 insertions, 66 deletions
diff --git a/src/afl-fuzz-one.c b/src/afl-fuzz-one.c index 72383727..1f0bf30e 100644 --- a/src/afl-fuzz-one.c +++ b/src/afl-fuzz-one.c @@ -24,6 +24,8 @@ */ #include "afl-fuzz.h" +#include <string.h> +#include <limits.h> /* MOpt */ @@ -362,6 +364,8 @@ static void locate_diffs(u8 *ptr1, u8 *ptr2, u32 len, s32 *first, s32 *last) { #endif /* !IGNORE_FINDS */ +#define BUF_PARAMS(name) (void **)&afl->name##_buf, &afl->name##_size + /* Take the current entry from the queue, fuzz it for a while. This function is a tad too long... returns 0 if fuzzed successfully, 1 if skipped or bailed out. */ @@ -1854,6 +1858,21 @@ havoc_stage: /* We essentially just do several thousand runs (depending on perf_score) where we take the input file and make random stacked tweaks. */ + u32 r_max, r; + + if (unlikely(afl->expand_havoc)) { + + /* add expensive havoc cases here, they are activated after a full + cycle without finds happened */ + + r_max = 16 + ((afl->extras_cnt + afl->a_extras_cnt) ? 2 : 0); + + } else { + + r_max = 15 + ((afl->extras_cnt + afl->a_extras_cnt) ? 2 : 0); + + } + for (afl->stage_cur = 0; afl->stage_cur < afl->stage_max; ++afl->stage_cur) { u32 use_stacking = 1 << (1 + rand_below(afl, HAVOC_STACK_POW2)); @@ -1896,8 +1915,7 @@ havoc_stage: } - switch (rand_below( - afl, 15 + ((afl->extras_cnt + afl->a_extras_cnt) ? 2 : 0))) { + switch ((r = rand_below(afl, r_max))) { case 0: @@ -2192,85 +2210,198 @@ havoc_stage: } - /* Values 15 and 16 can be selected only if there are any extras - present in the dictionaries. */ + default: - case 15: { + if (likely(r <= 16 && (afl->extras_cnt || afl->a_extras_cnt))) { - /* Overwrite bytes with an extra. */ + /* Values 15 and 16 can be selected only if there are any extras + present in the dictionaries. */ - if (!afl->extras_cnt || (afl->a_extras_cnt && rand_below(afl, 2))) { + if (r == 15) { - /* No user-specified extras or odds in our favor. Let's use an - auto-detected one. */ + /* Overwrite bytes with an extra. */ - u32 use_extra = rand_below(afl, afl->a_extras_cnt); - u32 extra_len = afl->a_extras[use_extra].len; - u32 insert_at; + if (!afl->extras_cnt || + (afl->a_extras_cnt && rand_below(afl, 2))) { - if (extra_len > temp_len) { break; } + /* No user-specified extras or odds in our favor. Let's use an + auto-detected one. */ - insert_at = rand_below(afl, temp_len - extra_len + 1); - memcpy(out_buf + insert_at, afl->a_extras[use_extra].data, - extra_len); + u32 use_extra = rand_below(afl, afl->a_extras_cnt); + u32 extra_len = afl->a_extras[use_extra].len; + u32 insert_at; - } else { + if (extra_len > temp_len) { break; } - /* No auto extras or odds in our favor. Use the dictionary. */ + insert_at = rand_below(afl, temp_len - extra_len + 1); + memcpy(out_buf + insert_at, afl->a_extras[use_extra].data, + extra_len); - u32 use_extra = rand_below(afl, afl->extras_cnt); - u32 extra_len = afl->extras[use_extra].len; - u32 insert_at; + } else { - if (extra_len > temp_len) { break; } + /* No auto extras or odds in our favor. Use the dictionary. */ - insert_at = rand_below(afl, temp_len - extra_len + 1); - memcpy(out_buf + insert_at, afl->extras[use_extra].data, extra_len); + u32 use_extra = rand_below(afl, afl->extras_cnt); + u32 extra_len = afl->extras[use_extra].len; + u32 insert_at; - } + if (extra_len > temp_len) { break; } - break; + insert_at = rand_below(afl, temp_len - extra_len + 1); + memcpy(out_buf + insert_at, afl->extras[use_extra].data, + extra_len); - } + } - case 16: { + break; - u32 use_extra, extra_len, insert_at = rand_below(afl, temp_len + 1); - u8 *ptr; + } else { // case 16 + + u32 use_extra, extra_len, + insert_at = rand_below(afl, temp_len + 1); + u8 *ptr; + + /* Insert an extra. Do the same dice-rolling stuff as for the + previous case. */ + + if (!afl->extras_cnt || + (afl->a_extras_cnt && rand_below(afl, 2))) { + + use_extra = rand_below(afl, afl->a_extras_cnt); + extra_len = afl->a_extras[use_extra].len; + ptr = afl->a_extras[use_extra].data; + + } else { + + use_extra = rand_below(afl, afl->extras_cnt); + extra_len = afl->extras[use_extra].len; + ptr = afl->extras[use_extra].data; + + } + + if (temp_len + extra_len >= MAX_FILE) { break; } + + out_buf = ck_maybe_grow(BUF_PARAMS(out), temp_len + extra_len); + + /* Tail */ + memmove(out_buf + insert_at + extra_len, out_buf + insert_at, + temp_len - insert_at); + + /* Inserted part */ + memcpy(out_buf + insert_at, ptr, extra_len); - /* Insert an extra. Do the same dice-rolling stuff as for the - previous case. */ + temp_len += extra_len; - if (!afl->extras_cnt || (afl->a_extras_cnt && rand_below(afl, 2))) { + break; - use_extra = rand_below(afl, afl->a_extras_cnt); - extra_len = afl->a_extras[use_extra].len; - ptr = afl->a_extras[use_extra].data; + } } else { - use_extra = rand_below(afl, afl->extras_cnt); - extra_len = afl->extras[use_extra].len; - ptr = afl->extras[use_extra].data; + /* + switch (r) { - } + case 15: // fall through + case 16: + case 17: {*/ - if (temp_len + extra_len >= MAX_FILE) { break; } + /* Overwrite bytes with a randomly selected chunk from another + testcase or insert that chunk. */ - out_buf = ck_maybe_grow(BUF_PARAMS(out), temp_len + extra_len); + if (afl->queued_paths < 4) break; - /* Tail */ - memmove(out_buf + insert_at + extra_len, out_buf + insert_at, - temp_len - insert_at); + /* Pick a random queue entry and seek to it. */ - /* Inserted part */ - memcpy(out_buf + insert_at, ptr, extra_len); + u32 tid; + do + tid = rand_below(afl, afl->queued_paths); + while (tid == afl->current_entry); - temp_len += extra_len; + struct queue_entry *target = afl->queue_buf[tid]; - break; + /* Make sure that the target has a reasonable length. */ - } + while (target && (target->len < 2 || target == afl->queue_cur)) + target = target->next; + + if (!target) break; + + /* Read the testcase into a new buffer. */ + + fd = open(target->fname, O_RDONLY); + + if (unlikely(fd < 0)) { + + PFATAL("Unable to open '%s'", target->fname); + + } + + u32 new_len = target->len; + u8 *new_buf = ck_maybe_grow(BUF_PARAMS(in_scratch), new_len); + + ck_read(fd, new_buf, new_len, target->fname); + + close(fd); + + u8 overwrite = 0; + if (temp_len >= 2 && rand_below(afl, 2)) + overwrite = 1; + else if (temp_len + HAVOC_BLK_XL >= MAX_FILE) { + + if (temp_len >= 2) + overwrite = 1; + else + break; + + } + + if (overwrite) { + + u32 copy_from, copy_to, copy_len; + + copy_len = choose_block_len(afl, new_len - 1); + if (copy_len > temp_len) copy_len = temp_len; + + copy_from = rand_below(afl, new_len - copy_len + 1); + copy_to = rand_below(afl, temp_len - copy_len + 1); + + memmove(out_buf + copy_to, new_buf + copy_from, copy_len); + + } else { + + u32 clone_from, clone_to, clone_len; + + clone_len = choose_block_len(afl, new_len); + clone_from = rand_below(afl, new_len - clone_len + 1); + + clone_to = rand_below(afl, temp_len); + + u8 *temp_buf = + ck_maybe_grow(BUF_PARAMS(out_scratch), temp_len + clone_len); + + /* Head */ + + memcpy(temp_buf, out_buf, clone_to); + + /* Inserted part */ + + memcpy(temp_buf + clone_to, new_buf + clone_from, clone_len); + + /* Tail */ + memcpy(temp_buf + clone_to + clone_len, out_buf + clone_to, + temp_len - clone_to); + + swap_bufs(BUF_PARAMS(out), BUF_PARAMS(out_scratch)); + out_buf = temp_buf; + temp_len += clone_len; + + } + + break; + + } + + // end of default: } @@ -2357,20 +2488,7 @@ retry_splicing: } while (tid == afl->current_entry); afl->splicing_with = tid; - target = afl->queue; - - while (tid >= 100) { - - target = target->next_100; - tid -= 100; - - } - - while (tid--) { - - target = target->next; - - } + target = afl->queue_buf[tid]; /* Make sure that the target has a reasonable length. */ @@ -4750,7 +4868,7 @@ u8 fuzz_one(afl_state_t *afl) { return (key_val_lv_1 | key_val_lv_2); -#undef BUF_PARAMS - } +#undef BUF_PARAMS + |