vuzzer generate a huge bbc.out file when fuzzing ffmpeg

[zjuchenyuan]

fuzzing command:

python runfuzzer.py -s '/d/p/normal/15.ffmpeg -y -i %s -c:v mpeg4 -c:a copy -f mp4 /dev/null' -i /d/seed/avi/ -w /d/p/vbin/pkl/15.ffmpeg.pkl -n /d/p/vbin/names/15.ffmpeg.names -o '0x00000000'

Parallel running 30 instances for about 6 days, I found that some of the bbc.out is very big:

# ls -alh */bbc.out
-rw-r--r-- 1 root root 136K May 30 23:51 vuzzer15_10/bbc.out
-rw-r--r-- 1 root root 136K May 31 04:47 vuzzer15_11/bbc.out
-rw-r--r-- 1 root root 136K May 31 01:44 vuzzer15_12/bbc.out
-rw-r--r-- 1 root root  36K Jun  1 00:32 vuzzer15_13/bbc.out
-rw-r--r-- 1 root root 136K May 31 20:53 vuzzer15_14/bbc.out
-rw-r--r-- 1 root root 136K May 31 00:19 vuzzer15_15/bbc.out
-rw-r--r-- 1 root root 136K May 31 23:06 vuzzer15_16/bbc.out
-rw-r--r-- 1 root root 136K Jun  1 00:17 vuzzer15_17/bbc.out
-rw-r--r-- 1 root root  34G Jun  1 00:19 vuzzer15_18/bbc.out
-rw-r--r-- 1 root root    0 Jun  1 00:32 vuzzer15_19/bbc.out
-rw-r--r-- 1 root root 136K Jun  1 00:28 vuzzer15_1/bbc.out
-rw-r--r-- 1 root root  44G May 31 07:54 vuzzer15_20/bbc.out
-rw-r--r-- 1 root root 136K May 30 19:05 vuzzer15_21/bbc.out
-rw-r--r-- 1 root root 136K May 31 16:39 vuzzer15_22/bbc.out
-rw-r--r-- 1 root root 136K May 31 14:41 vuzzer15_23/bbc.out
-rw-r--r-- 1 root root    0 Jun  1 00:32 vuzzer15_24/bbc.out
-rw-r--r-- 1 root root 136K May 31 14:10 vuzzer15_25/bbc.out
-rw-r--r-- 1 root root 136K May 30 22:59 vuzzer15_26/bbc.out
-rw-r--r-- 1 root root 136K May 31 23:10 vuzzer15_27/bbc.out
-rw-r--r-- 1 root root  67G May 29 17:55 vuzzer15_28/bbc.out
-rw-r--r-- 1 root root 136K May 30 05:59 vuzzer15_29/bbc.out
-rw-r--r-- 1 root root 136K May 30 22:41 vuzzer15_2/bbc.out
-rw-r--r-- 1 root root 136K May 30 06:22 vuzzer15_30/bbc.out
-rw-r--r-- 1 root root    0 May 26 16:01 vuzzer15_3/bbc.out
-rw-r--r-- 1 root root 136K May 31 14:55 vuzzer15_4/bbc.out
-rw-r--r-- 1 root root 136K May 31 23:35 vuzzer15_5/bbc.out
-rw-r--r-- 1 root root  42G May 26 18:36 vuzzer15_6/bbc.out
-rw-r--r-- 1 root root 136K May 31 00:38 vuzzer15_7/bbc.out
-rw-r--r-- 1 root root 136K May 31 02:17 vuzzer15_8/bbc.out
-rw-r--r-- 1 root root 136K May 31 23:55 vuzzer15_9/bbc.out

Is this expected? By looking the file, I found some addresses occur periodly, like:

# grep '0x9a322d' bbc.out |wc -l
68287706

Maybe the program is in a dead loop state?

[tosanjay]

Hi, Sorry about not being able to respond. I have just relocated to a different country and trying to settling in. I will get back to it ASAP. meanwhile, if you can find out which input cause a huge bbc.out, try running only ffmpeg with it and observe the behaviour.