Re: [PATCH nft] initial support for the afl++ (american fuzzy lop++) fuzzer

[Phil Sutter <phil@nwl.cc>]

On Wed, Dec 06, 2023 at 08:43:42AM +0100, Florian Westphal wrote:
> Phil Sutter <phil@nwl.cc> wrote:
> > > +__AFL_FUZZ_INIT();
> > > +/* this get passed via afl-cc, declares prototypes
> > > + * depending on the afl-cc flavor.
> > > + */
> >
> > This comment seems out of place?
> 
> I wanted to add some explanation as to where this
> macro is defined/coming from.

Ah, so it relates to the preceding macro call. Maybe
s/this/above macro declaraction/ ?

> 
> > > +	len = strlen(buf);
> > > +
> > > +	rv = write(fd, buf, len);
> > 
> > So this sets input->fname to name and writes into the opened fd, but
> > what if savebuf() noticed buf fits into input->buffer and thus set
> > input->use_filename = false?
> 
> What about it?  The idea is to have an on-disk copy in case afl or the
> vm its running in crashes.

Hmm. Probably I miss the point regarding struct nft_afl_input. IMO, if
save_candidate() writes data into the file despite called savebuf()
setting use_filename = false, nft_afl_run_cmd() will try to read from
->buffer when it should read from ->fname.

Cheers, Phil