diff options
| -rw-r--r-- | include/afl-mutations.h | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/include/afl-mutations.h b/include/afl-mutations.h index 6338c93c..24c6b8ff 100644 --- a/include/afl-mutations.h +++ b/include/afl-mutations.h @@ -2490,12 +2490,13 @@ inline u32 afl_mutate(afl_state_t *afl, u8 *buf, u32 len, u32 steps, case MUT_INSERTASCIINUM: { - u32 len = 1 + rand_below(afl, 8); + u32 ins_len = 1 + rand_below(afl, 8); u32 pos = rand_below(afl, len); /* Insert ascii number. */ - if (unlikely(len < pos + len)) { + if (unlikely(len < pos + ins_len)) { + // no retry if we have a small input if (unlikely(len < 8)) { break; @@ -2511,7 +2512,20 @@ inline u32 afl_mutate(afl_state_t *afl, u8 *buf, u32 len, u32 steps, u64 val = rand_next(afl); char numbuf[32]; snprintf(numbuf, sizeof(numbuf), "%llu", val); - memcpy(buf + pos, numbuf, len); + size_t val_len = strlen(numbuf), off; + + if (ins_len > val_len) { + + ins_len = val_len; + off = 0; + + } else { + + off = val_len - ins_len; + + } + + memcpy(buf + pos, numbuf + off, ins_len); break; |