2.43b

afl-fuzz.c

@@ -114,6 +114,7 @@ EXP_ST u8  skip_deterministic,        /* Skip deterministic stages?       */
            in_place_resume,           /* Attempt in-place resume?         */
            auto_changed,              /* Auto-generated tokens changed?   */
            no_cpu_meter_red,          /* Feng shui on the status screen   */
+           no_arith,                  /* Skip most arithmetic ops         */
            shuffle_queue,             /* Shuffle input queue?             */
            bitmap_changed = 1,        /* Time to update bitmap?           */
            qemu_mode,                 /* Running in QEMU mode?            */
@@ -4546,8 +4547,6 @@ static u8 trim_case(char** argv, struct queue_entry* q, u8* in_buf) {
 
   }
 
-
-
 abort_trimming:
 
   bytes_trim_out += q->len;
@@ -5395,6 +5394,8 @@ static u8 fuzz_one(char** argv) {
 
 skip_bitflip:
 
+  if (no_arith) goto skip_arith;
+
   /**********************
    * ARITHMETIC INC/DEC *
    **********************/
@@ -5708,7 +5709,7 @@ static u8 fuzz_one(char** argv) {
 
   /* Setting 16-bit integers, both endians. */
 
-  if (len < 2) goto skip_interest;
+  if (no_arith || len < 2) goto skip_interest;
 
   stage_name  = "interest 16/8";
   stage_short = "int16";
@@ -7882,6 +7883,7 @@ int main(int argc, char** argv) {
 
   if (getenv("AFL_NO_FORKSRV"))    no_forkserver    = 1;
   if (getenv("AFL_NO_CPU_RED"))    no_cpu_meter_red = 1;
+  if (getenv("AFL_NO_ARITH"))      no_arith = 1;
   if (getenv("AFL_SHUFFLE_QUEUE")) shuffle_queue    = 1;
 
   if (getenv("AFL_HANG_TMOUT")) {

config.h

@@ -21,7 +21,7 @@
 
 /* Version string: */
 
-#define VERSION             "2.42b"
+#define VERSION             "2.43b"
 
 /******************************************************
  *                                                    *

docs/ChangeLog

@@ -16,6 +16,13 @@ Not sure if you should upgrade? The lowest currently recommended version
 is 2.41b. If you're stuck on an earlier release, it's strongly advisable
 to get on with the times.
 
+--------------
+Version 2.43b:
+--------------
+
+  - Added AFL_NO_ARITH to aid in the fuzzing of text-based formats.
+    Requested by Jakub Wilk.
+
 --------------
 Version 2.42b:
 --------------

docs/env_variables.txt

@@ -123,6 +123,9 @@ checks or alter some of the more exotic semantics of the tool:
     don't want AFL to spend too much time classifying that stuff and just 
     rapidly put all timeouts in that bin.
 
+  - AFL_NO_ARITH causes AFL to skip most of the deterministic arithmetics.
+    This can be useful to speed up the fuzzing of text-based file formats.
+
   - AFL_SHUFFLE_QUEUE randomly reorders the input queue on startup. Requested
     by some users for unorthodox parallelized fuzzing setups, but not
     advisable otherwise.