On Thu, Dec 29, 2011 at 10:26:17AM -0800, Xin Li wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > On 12/29/11 06:39, John Baldwin wrote: > > Can you give some more details on why ftpd is triggering a dlopen > > inside of the chroot? It would appear that that is unrelated to > > helper programs (since setting a flag in libc in ftpd can't > > possibly affect helper programs ability to use dlopen() from within > > libc). > > Sure. That's because nsdispatch(3) would reload /etc/nsswitch.conf if > it notices a change. After chroot() the file is considered as > "chang"ed and thus it reloads the file as well as designated shared > libraries.
Another proposal more close to @secteam version, but less ugly: to have public API rtld function (or env variable) which prevents _any_ dlopen(), not guarded currently by libc only. That way only rtld and ftpd's needs to be rebuilded, but not libc itself. -- http://ache.vniz.net/ _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-security To unsubscribe, send any mail to "[email protected]"
