From: Theodore Ts'o <tytso-3s7WtUTddSA@public.gmane.org>
To: Josh Triplett <josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org>
Cc: Andy Lutomirski <luto-kltTT9wpgjJwATOyAt5JVQ@public.gmane.org>,
"Eric W. Biederman"
<ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
Michael Kerrisk-manpages
<mtk.manpages-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>,
Linux API <linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
linux-man <linux-man-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
Subject: Re: [PATCH 2/2] groups: Allow unprivileged processes to use setgroups to drop groups
Date: Sat, 15 Nov 2014 21:05:11 -0500 [thread overview]
Message-ID: <20141116020511.GB5507@thunk.org> (raw)
In-Reply-To: <20141115202042.GA20900@thin>
On Sat, Nov 15, 2014 at 12:20:42PM -0800, Josh Triplett wrote:
> > However, sudoers seems to allow negative group matches. So maybe
> > allowing this only with no_new_privs already set would make sense.
>
> Sigh, bad sudo. Sure, restricting this to no_new_privs only seems fine.
> I'll do that in v2, and document that in the manpage.
I've also seen use cases (generally back in the bad old days of big
timesharing VAX 750's :-) where the system admin might assign someone
to the "games-abusers" group, and then set /usr/games to mode 705
root:games-abusers --- presumably because it's easier to add a few
people to the deny list rather than having to add all of the EECS
department to the games group minus the abusers.
So arbitrarily anyone to drop groups from their supplemental group
list will result in a change from both existing practice and legacy
Unix systems, and it could potentially lead to a security exposure.
Cheers,
- Ted
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next prev parent reply other threads:[~2014-11-16 2:05 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-15 9:00 [PATCH 1/2] groups: Factor out a function to set a pre-sorted group list Josh Triplett
2014-11-15 9:01 ` [PATCH 2/2] groups: Allow unprivileged processes to use setgroups to drop groups Josh Triplett
[not found] ` <0895c1f268bc0b01cc6c8ed4607d7c3953f49728.1416041823.git.josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org>
2014-11-15 15:37 ` Eric W. Biederman
[not found] ` <87d28osceg.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-11-15 19:29 ` Josh Triplett
2014-11-15 20:06 ` Andy Lutomirski
[not found] ` <CALCETrUM=GqsOumTmDMF4B5GS1w=x56t41eE-2xW1bBOfUz02w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-11-15 20:20 ` Josh Triplett
2014-11-16 2:05 ` Theodore Ts'o [this message]
[not found] ` <20141116020511.GB5507-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2014-11-16 2:35 ` Josh Triplett
[not found] ` <6C690A2C-8EB1-421A-94C3-9803AFB95760-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org>
2014-11-16 3:08 ` Eric W. Biederman
[not found] ` <87vbmfq1uw.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-11-16 5:07 ` Josh Triplett
2014-11-16 13:32 ` Theodore Ts'o
[not found] ` <20141116133230.GA32030-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2014-11-16 15:42 ` Andy Lutomirski
[not found] ` <CALCETrUPsH_So2Mgk38Fe_pjp5Y+cgjzCUe7fzFcnsFzivHeNA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-11-16 19:12 ` Josh Triplett
2014-11-16 19:09 ` Josh Triplett
2014-11-16 3:40 ` Theodore Ts'o
[not found] ` <20141116034005.GC5507-AKGzg7BKzIDYtjvyW6yDsg@public.gmane.org>
2014-11-16 4:52 ` Josh Triplett
2014-11-17 11:37 ` One Thousand Gnomes
[not found] ` <20141117113734.396798e6-qBU/x9rampVanCEyBjwyrvXRex20P6io@public.gmane.org>
2014-11-17 18:07 ` Andy Lutomirski
[not found] ` <CALCETrXi1qHyu4_U7cbROB74n461nBZ9R7=0kfhR8-VFAwOF1w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-11-17 22:11 ` Eric W.Biederman
[not found] ` <0b65fd07-48ea-483b-8fd5-fd84d0bff881-2ueSQiBKiTY7tOexoI0I+QC/G2K4zDHf@public.gmane.org>
2014-11-17 22:22 ` Andy Lutomirski
[not found] ` <CALCETrWXC5dMOXTTBOiq4Cv+yjqbA_UdmAN-TDmNAJUo+ABxtg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-11-17 22:37 ` josh-iaAMLnmF4UmaiuxdJuQwMA
2014-11-18 0:56 ` Casey Schaufler
2014-11-17 18:06 ` Casey Schaufler
[not found] ` <546A3942.5040906-iSGtlc1asvQWG2LlvL+J4A@public.gmane.org>
2014-11-17 18:31 ` Andy Lutomirski
2014-11-17 18:46 ` Andy Lutomirski
2014-11-17 18:51 ` Casey Schaufler
[not found] ` <546A43CE.2030706-iSGtlc1asvQWG2LlvL+J4A@public.gmane.org>
2014-11-27 16:59 ` [CFT][PATCH] userns: Avoid problems with negative groups Eric W. Biederman
[not found] ` <87lhmwwpey.fsf_-_-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-11-27 20:52 ` Andy Lutomirski
[not found] ` <CALCETrUuWDq2akKfb50AiPHeDDWzPW7ijz1QwnuNiskyZbBEfA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-11-28 5:21 ` Eric W. Biederman
[not found] ` <87wq6frjcw.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-11-28 5:22 ` [CFT][PATCH v2] " Eric W. Biederman
2014-11-28 15:11 ` [CFT][PATCH] " Andy Lutomirski
[not found] ` <CALCETrX2s-7iaLMEKLQsExTEp3JyoAPQG44p0v5wkeED3-6dQA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-11-28 16:34 ` Eric W. Biederman
[not found] ` <874mtjp9m1.fsf-JOvCrm2gF+uungPnsOpG7nhyD016LWXt@public.gmane.org>
2014-11-28 17:11 ` Andy Lutomirski
[not found] ` <CALCETrVn4gVXp7F=5h-bkN5VWuRMG9BoxgeQfKhX4+ZXxGE=wQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-11-17 22:41 ` [PATCH 2/2] groups: Allow unprivileged processes to use setgroups to drop groups Eric W.Biederman
[not found] ` <9f43a787-165e-4256-a097-f7691204d9d6-2ueSQiBKiTY7tOexoI0I+QC/G2K4zDHf@public.gmane.org>
2014-11-17 22:50 ` Andy Lutomirski
[not found] ` <CALCETrU2tXM5sKx=L-K6=ARkvqefkcZHW3_RGhsgfc31FuWxJg-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-11-17 23:13 ` josh-iaAMLnmF4UmaiuxdJuQwMA
[not found] ` <3ccec8a13019b5e8ce7b1d7889677b778b070dc8.1416041823.git.josh-iaAMLnmF4UmaiuxdJuQwMA@public.gmane.org>
2014-11-15 9:01 ` [PATCH manpages] getgroups.2: Document unprivileged setgroups calls Josh Triplett
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