Re: think twice before enabling -D_FORTIFY_SOURCE=2 for C projects without thorough build-time testing
On Fri, 20 Sep 2013, Kees Cook wrote:
> This is absolutely a bug in glibc. While the spec can say "undefined", it
> is, in fact, not undefined. It worked in a very specific way for over a
> decade, so that's pretty well defined. ;) The fortify function has no need
> to change it.
> > To mitigate this issue, besides reporting upstream, for now I had to disable
> > this fortification with
> > DEB_BUILD_HARDENING_FORTIFY := 0
> > preceding inclusion of /usr/share/hardening-includes/hardening.make
> Instead, if eglibc continues to remain unfixed, you can replace the
> "buggy" sprintf calls with the suggestions listed in my original mass
> bug-filing email above.
Thanks Kees! upstream resolved it already... I will eventually add
unittests for this and rebuild freshier upstream.
Yaroslav O. Halchenko, Ph.D.
http://neuro.debian.net http://www.pymvpa.org http://www.fail2ban.org
Senior Research Associate, Psychological and Brain Sciences Dept.
Dartmouth College, 419 Moore Hall, Hinman Box 6207, Hanover, NH 03755
Phone: +1 (603) 646-9834 Fax: +1 (603) 646-1419