All testcases timeout! afl giving up!!!

[Fatimah Aljaafari]

Dear Afl-users, 

I have a problem when I run my code with a custom llvm pass. 

I wrote my own llvm pass which inserts a function after each instruction. 

when I compile it using AFL-clang it compiles fine. I use the following commands:

afl-clang -O2 -g -fsanitize=thread -fsanitize=undefined -Xclang -load -Xclang MyPass.so test.c -lpthread -L. -lmylib

where -lmylib is the library which contains the function.

However, when I run it using afl-fuzz it skips all the test cases as in the attached I used the following command:

afl-fuzz -i in -m none -t 100+ -o AFL_Results ./a.out

is there any way to make afl works with my instrumentation? (ps. it runs without the instrumentation!)

Thanks for your help in advance. 

picture! 

[Michal Zalewski]

> However, when I run it using afl-fuzz it skips all the test cases as in the attached I used the following command:
> afl-fuzz -i in -m none -t 100+ -o AFL_Results ./a.out

Hate to ask, but have you tried specifying a more substantial timeout,
or letting AFL auto-calibrate (i.e., not providing the -t value at
all)?

Also, is the program doing anything beyond reading data from stdin and
then transforming it in some way? I.e., any network / IPC, anything
else that could cause it to be slow or stall?

/mz

[Fatimah Aljaafari]

> Hate to ask, but have you tried specifying a more substantial timeout,
or letting AFL auto-calibrate (i.e., not providing the -t value at
all)?

Yes, and it was a timeout and AFL suggested to use t.  

> Also, is the program doing anything beyond reading data from stdin and
then transforming it in some way? I.e., any network / IPC, anything
else that could cause it to be slow or stall?

Actually, this is was the problem. the instrumentation was injecting a delay after each instruction which caused the program to be slow. After decreasing the time of the delay AFL was working fine. 

Thanks for your reply.  

[Fatimah Aljaafari]

I tried another source code with the same instrumentation. But I got this error as in the picture. 

Do you know what is causing this? and how to overcome it?

Many thanks, 

Fatimah