[Libguestfs] Fuzzing Question

[Eric Blake]

On 3/18/20 1:24 PM, habib dan aouta wrote:
> So I installed Libnbd which worked fined and then I was trying to run  Libnbd-fuzz-wrapper.c and with afl using :
> afl-fuzz -i fuzzing/testcase_dir -o fuzzing/sync_dir -M fuzz01 \./fuzzing/libnbd-fuzz-wrapper @@
> 
>   when I try that command it gives me an error saying Libnbd-fuzz-wrapper.c is not an EFL  binary.  Then I tried to compile Libnbd-fuzz-wrapper.c first into an executable file and then I get the following error:
> libnbd-fuzz-wrapper.c:130:3: warning: implicit declaration of function 'nbd_connect_socket' [-Wimplicit-function-declaration]
>     nbd_connect_socket (nbd, sock);
> 
> I also added the #include<libnbd.h> into the Libnbd-fuzz-wrapper.c but still getting the same error.
> 
> Finally I ran this command : ld -lnbd —verbose and I found out libnbd library is missing
> attempt to open //usr/local/lib/x86_64-linux-gnu/libnbd.so failed

Hmm. That does not happen on Linux, but IS a typical error message on 
Cygwin.  POSIX says that file names beginning with //name are 
implementation-defined; Linux defines them to resolve to /name, Cygwin 
defines them to be access to a file on the remote machine 'name' (as a 
nod to Windows \\server\share\file).  If there is no remote machine 
named //usr in your network, that would explain not only this message, 
but also the message about libnbd-fuzz-wrapper not being an ELF binary 
(Windows uses pe-coff rather than ELF file format for its binaries, and 
I have no idea if afl can even begin to work with pe-coff).

But since you didn't give us details about your platform, I'm shooting 
in the dark.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org