Date: Fri, 23 Dec 2011 13:20:34 -0500 From: Alexander Kabaev <kabaev@gmail.com> To: Kostik Belousov <kostikbel@gmail.com> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org, Colin Percival <cperciva@freebsd.org>, John Baldwin <jhb@freebsd.org> Subject: Re: svn commit: r228843 - head/contrib/telnet/libtelnet head/crypto/heimdal/appl/telnet/libtelnet head/include head/lib/libc/gen head/lib/libc/iconv head/lib/libc/include head/lib/libc/net head/libexec... Message-ID: <20111223132034.12192baa@kan.dyndns.org> In-Reply-To: <20111223175143.GJ50300@deviant.kiev.zoral.com.ua> References: <201112231500.pBNF0c0O071712@svn.freebsd.org> <201112231058.46642.jhb@freebsd.org> <201112231122.34436.jhb@freebsd.org> <20111223120644.75fe944d@kan.dyndns.org> <20111223175143.GJ50300@deviant.kiev.zoral.com.ua>
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--Sig_/5lcKqYi_CebwpwoL9c8Y+NN Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Fri, 23 Dec 2011 19:51:43 +0200 Kostik Belousov <kostikbel@gmail.com> wrote: > On Fri, Dec 23, 2011 at 12:06:44PM -0500, Alexander Kabaev wrote: > > On Fri, 23 Dec 2011 11:22:34 -0500 > > John Baldwin <jhb@freebsd.org> wrote: > >=20 > > > On Friday, December 23, 2011 10:58:46 am John Baldwin wrote: > > > > On Friday, December 23, 2011 10:00:38 am Colin Percival wrote: > > > > > Author: cperciva > > > > > Date: Fri Dec 23 15:00:37 2011 > > > > > New Revision: 228843 > > > > > URL: http://svn.freebsd.org/changeset/base/228843 > > > > >=20 > > > > > Log: > > > > > Fix a problem whereby a corrupt DNS record can cause named > > > > > to crash. [11:06]=20 > > > > > Add an API for alerting internal libc routines to the > > > > > presence of "unsafe" paths post-chroot, and use it in ftpd. > > > > > [11:07] > > > >=20 > > > > Eh, the whole libc_dlopen() thing looks like a gross hack (and > > > > who came up with that weird symbol name for a public API????). > > > > Is it really even needed given the other fix to have ftpd drop > > > > privilege before execing a helper program? I guess the main > > > > reason I don't like it is it doesn't do anything to address the > > > > more general problem. I would have expected instead something > > > > to restrict dlopen() entirely including from other libraries > > > > than just libc in certain circumstances. > > >=20 > > > At the very least if we feel that the libc_dlopen() thing is a > > > temporary band-aid, we should move the new symbols into the > > > private namespace so we can remove them once the better fix is in > > > rather than being required to support them forever. > libc_dlopen() is not exposed. > The __FreeBSD_libc_enter_restricted_mode() is, and its name is ugly > exactly to note the ugly intent. I do not see how the symbol can go > int FBSDprivate_1.0 when it was supposed to be used by third-party > applications. >=20 > Putting this hack into rtld itself IMO has to wide consequences. > For libc, we can enumerate the points that stop work after the call, > but for the generic applications the consequences are undefined. > > >=20 > > > --=20 > > > John Baldwin > >=20 > > Pardon for not catching that when I had a chance to influence the > > outcome, but I would like to voice my support to tucking the > > ugliness into private version namespace. > >=20 > > --=20 > > Alexander Kabaev >=20 Putting symbol into official namespace implies that we are willing to provide and maintain it forever, which I do not think was the intent for the function in question. FBSD_PRIVATE says nothing about who should and should not link to it, only the level of API stability one has to expect in the end. If/when we have better security mechanisms (capsicum?) available to users by default, this should be ripped out with extreme prejudice. --=20 Alexander Kabaev --Sig_/5lcKqYi_CebwpwoL9c8Y+NN Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (FreeBSD) iD8DBQFO9MZ3Q6z1jMm+XZYRAivLAJ41jrp3y8Rx6Y1DMQrsVlraRSo5cQCfXtVN GlxoyBzrnlS+o8xRj9ZO3v4= =YO7h -----END PGP SIGNATURE----- --Sig_/5lcKqYi_CebwpwoL9c8Y+NN--
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