memory grab at startup to prevent crashes
MODIFY
src/afl-fuzz-one.c
src/afl-fuzz-one.c
@@ -564,7 +564,7 @@ u8 fuzz_one_original(afl_state_t *afl) {
single byte anyway, so it wouldn't give us any performance or memory usage
benefits. */
- out_buf = ck_maybe_grow(BUF_PARAMS(out), len + 4096);
+ out_buf = ck_maybe_grow(BUF_PARAMS(out), len);
afl->subseq_tmouts = 0;
@@ -1637,7 +1637,7 @@ skip_interest:
orig_hit_cnt = new_hit_cnt;
- ex_tmp = ck_maybe_grow(BUF_PARAMS(ex), len + MAX_DICT_FILE + 4096);
+ ex_tmp = ck_maybe_grow(BUF_PARAMS(ex), len + MAX_DICT_FILE);
for (i = 0; i <= (u32)len; ++i) {
@@ -1811,7 +1811,7 @@ custom_mutator_stage:
fd = open(target->fname, O_RDONLY);
if (unlikely(fd < 0)) { PFATAL("Unable to open '%s'", target->fname); }
- new_buf = ck_maybe_grow(BUF_PARAMS(out_scratch), target->len + 4096);
+ new_buf = ck_maybe_grow(BUF_PARAMS(out_scratch), target->len);
ck_read(fd, new_buf, target->len, target->fname);
close(fd);
@@ -1986,7 +1986,7 @@ havoc_stage:
temp_len = new_len;
if (out_buf != custom_havoc_buf) {
- ck_maybe_grow(BUF_PARAMS(out), temp_len + 4096);
+ ck_maybe_grow(BUF_PARAMS(out), temp_len);
memcpy(out_buf, custom_havoc_buf, temp_len);
}
@@ -2235,7 +2235,7 @@ havoc_stage:
clone_to = rand_below(afl, temp_len);
new_buf = ck_maybe_grow(BUF_PARAMS(out_scratch),
- temp_len + clone_len + 4096);
+ temp_len + clone_len);
/* Head */
@@ -2402,7 +2402,7 @@ havoc_stage:
if (temp_len + extra_len >= MAX_FILE) { break; }
out_buf =
- ck_maybe_grow(BUF_PARAMS(out), temp_len + extra_len + 4096);
+ ck_maybe_grow(BUF_PARAMS(out), temp_len + extra_len);
/* Tail */
memmove(out_buf + insert_at + extra_len, out_buf + insert_at,
@@ -2498,7 +2498,7 @@ havoc_stage:
clone_to = rand_below(afl, temp_len);
u8 *temp_buf = ck_maybe_grow(BUF_PARAMS(out_scratch),
- temp_len + clone_len + 4096);
+ temp_len + clone_len);
/* Head */
@@ -2533,7 +2533,7 @@ havoc_stage:
/* out_buf might have been mangled a bit, so let's restore it to its
original size and shape. */
- out_buf = ck_maybe_grow(BUF_PARAMS(out), len + 4096);
+ out_buf = ck_maybe_grow(BUF_PARAMS(out), len);
temp_len = len;
memcpy(out_buf, in_buf, len);
@@ -2660,7 +2660,7 @@ retry_splicing:
swap_bufs(BUF_PARAMS(in), BUF_PARAMS(in_scratch));
in_buf = new_buf;
- out_buf = ck_maybe_grow(BUF_PARAMS(out), len + 4096);
+ out_buf = ck_maybe_grow(BUF_PARAMS(out), len);
memcpy(out_buf, in_buf, len);
goto custom_mutator_stage;

MODIFY
src/afl-fuzz.c
src/afl-fuzz.c
@@ -1305,6 +1305,17 @@ int main(int argc, char **argv_orig, char **envp) {
OKF("Taint forkserver successfully started");
+#define BUF_PARAMS(name) (void **)&afl->name##_buf, &afl->name##_size
+ u8 *tmp1 = ck_maybe_grow(BUF_PARAMS(eff), MAX_FILE + 4096);
+ u8 *tmp2 = ck_maybe_grow(BUF_PARAMS(ex), MAX_FILE + 4096);
+ u8 *tmp3 = ck_maybe_grow(BUF_PARAMS(in_scratch), MAX_FILE + 4096);
+ u8 *tmp4 = ck_maybe_grow(BUF_PARAMS(out), MAX_FILE + 4096);
+ u8 *tmp5 = ck_maybe_grow(BUF_PARAMS(out_scratch), MAX_FILE + 4096);
+#undef BUF_PARAMS
+
+ if (!tmp1 || !tmp2 || !tmp3 || !tmp4 || !tmp5)
+ FATAL("memory issues. me hungry, feed me!");
+
}
perform_dry_run(afl);

memory grab at startup to prevent crashes