Re: [PATCH v4 2/5] t5000: test tar files that overflow ustar headers

> > So off_t is probably better. We do need to be careful, though, when
> > allocating objects. E.g., this:
> > 
> >   off_t size;
> >   struct git_istream *stream;
> >   void *buf;
> > 
> >   stream = open_istream(sha1, &type, &size, NULL);
> >   buf = xmalloc(size);
> >   while (1) {
> > 	/* read stream into buf */
> >   }
> > 
> > is a security hole when size_t is less than off_t (it gets truncated in
> > the call to xmalloc, which allocates too few bytes). This is a toy
> > example, obviously, but it's something to watch out for.
> > 
> That code is "illegal", it should be
>  buf = xmalloc(xsize_t(size));