fix negative stability bug (hopefully)
MODIFY
docs/Changelog.md
docs/Changelog.md
@@ -13,6 +13,8 @@ sending a mail to <afl-users+subscribe@googlegroups.com>.
- afl-fuzz:
- AFL_MAP_SIZE was not working correctly
- better python detection
+ - an old, old bug in afl that would show negative stability in rare
+ circumstances is now hopefully fixed
- llvm_mode:
- if LLVM 11 is installed the posix shm_open+mmap is used and a fixed
address for the shared memory map is used as this increases the

MODIFY
src/afl-fuzz-run.c
src/afl-fuzz-run.c
@@ -193,6 +193,8 @@ u8 calibrate_case(afl_state_t *afl, struct queue_entry *q, u8 *use_mem,
if (q->exec_cksum) {
memcpy(afl->first_trace, afl->fsrv.trace_bits, afl->fsrv.map_size);
+ u8 hnb = has_new_bits(afl, afl->virgin_bits);
+ if (hnb > new_bits) { new_bits = hnb; }
}
@@ -226,12 +228,11 @@ u8 calibrate_case(afl_state_t *afl, struct queue_entry *q, u8 *use_mem,
}
cksum = hash32(afl->fsrv.trace_bits, afl->fsrv.map_size, HASH_CONST);
-
- if (q->exec_cksum != cksum) {
-
u8 hnb = has_new_bits(afl, afl->virgin_bits);
if (hnb > new_bits) { new_bits = hnb; }
+ if (q->exec_cksum != cksum) {
+
if (q->exec_cksum) {
u32 i;

fix negative stability bug (hopefully)