From 67d2e6319bed90c06cf54b5d9a7a4bae51df317d Mon Sep 17 00:00:00 2001 From: h1994st Date: Sat, 18 Jul 2020 23:20:32 -0400 Subject: Skip the empty test case generated by the custom trimming --- src/afl-fuzz-mutators.c | 11 +++++++++++ src/afl-fuzz-run.c | 2 +- 2 files changed, 12 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/afl-fuzz-mutators.c b/src/afl-fuzz-mutators.c index 9fc77ffe..f6b36843 100644 --- a/src/afl-fuzz-mutators.c +++ b/src/afl-fuzz-mutators.c @@ -286,6 +286,15 @@ u8 trim_case_custom(afl_state_t *afl, struct queue_entry *q, u8 *in_buf, "Trimmed data returned by custom mutator is larger than original " "data"); + } else if (unlikely(retlen == 0)) { + + /* Do not run the empty test case on the target. To keep the custom + trimming function running, we simply treat the empty test case as an + unsuccessful trimming and skip it, instead of aborting the trimming. */ + + ++afl->trim_execs; + goto unsuccessful_trimming; + } write_to_testcase(afl, retbuf, retlen); @@ -325,6 +334,8 @@ u8 trim_case_custom(afl_state_t *afl, struct queue_entry *q, u8 *in_buf, } else { +unsuccessful_trimming: + /* Tell the custom mutator that the trimming was unsuccessful */ afl->stage_cur = mutator->afl_custom_post_trim(mutator->data, 0); if (unlikely(afl->stage_cur < 0)) { diff --git a/src/afl-fuzz-run.c b/src/afl-fuzz-run.c index f1da9c65..2a1664e2 100644 --- a/src/afl-fuzz-run.c +++ b/src/afl-fuzz-run.c @@ -109,7 +109,7 @@ void write_to_testcase(afl_state_t *afl, void *mem, u32 len) { }); - if (unlikely(!new_buf && (new_size < 0))) { + if (unlikely(!new_buf && (new_size <= 0))) { FATAL("Custom_post_process failed (ret: %lu)", (long unsigned)new_size); -- cgit 1.4.1