[PATCH v4 08/14] Use NT_FILE note section for reading core target memory

[Kevin Buettner]

On Fri, 10 Jul 2020 21:08:27 +0100
Pedro Alves <pedro@palves.net> wrote:

> > +	/* Make new BFD section.  */
> > +	char secnamebuf[64];
> > +	sprintf (secnamebuf, "S%04d", num);
> > +	char *secname = (char *) bfd_alloc (bfd, strlen (secnamebuf) + 1);
> > +	if (secname == nullptr)
> > +	  error (_("Out of memory"));
> > +	strcpy (secname, secnamebuf);
> > +	asection *sec = bfd_make_section_anyway (bfd, secname);
> > +	if (sec == nullptr)
> > +	  error (_("Can't make section"));  
> 
> SECNAME leaks if you throw here.  Use a unique pointer?

It turns out that this code will leak even if the error pathway is not
taken.  After studying bfd/section.c, it appears that nothing ever
frees the section name.  bfd_make_section_anyway{,with_flags} is
usually (though not always) called with a constant string like
".dynstr", ".plt", ".buildid", etc.  In those cases where it is passed
a dynamically allocated string, I see no provision for freeing the
section name.  I strongly suspect that there are leaks where this
occurs.

It turns out that bfd_make_section_anyway() will create a new
section even if passed a name of an already existing section.  I'm
experimenting with just passing in "load" as the name for each
needed section.  So far, it seems to work.

Kevin