To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: "Serge E. Hallyn" <serue@us.ibm.com>,
       "Andrew G. Morgan" <morgan@kernel.org>,
       Bryan Donlan <bdonlan@gmail.com>,
       Benny Amorsen <benny+usenet@amorsen.dk>,
       Michael Stone <michael@laptop.org>, linux-kernel@vger.kernel.org,
       netdev@vger.kernel.org, linux-security-module@vger.kernel.org,
       Andi Kleen <andi@firstfloor.org>, David Lang <david@lang.hm>,
       Oliver Hartkopp <socketcan@hartkopp.net>,
       Herbert Xu <herbert@gondor.apana.org.au>,
       Valdis Kletnieks <Valdis.Kletnieks@vt.edu>,
       Evgeniy Polyakov <zbr@ioremap.net>,
       "C. Scott Ananian" <cscott@cscott.net>,
       James Morris <jmorris@namei.org>, Bernie Innocenti <bernie@codewiz.org>,
       Mark Seaborn <mrs@mythic-beasts.com>,
       Randy Dunlap <randy.dunlap@oracle.com>,
       =?utf-8?Q?Am=C3=A9rico?= Wang <xiyou.wangcong@gmail.com>,
       Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
       Samir Bellabes <sam@synack.fr>,
       Casey Schaufler <casey@schaufler-ca.com>, Pavel Machek <pavel@ucw.cz>,
       Al Viro <viro@zeniv.linux.org.uk>
Subject: Re: [RFC][PATCH v3] Unprivileged: Disable raising of privileges
References: <m1iqbpwjtp.fsf@fess.ebiederm.org>
	<20091229223631.GB22578@us.ibm.com>
	<m1aax1uoa3.fsf_-_@fess.ebiederm.org>
	<3e8340490912291954v5a837a26p64bd776102d281d7@mail.gmail.com>
	<m1r5qdt721.fsf@fess.ebiederm.org>
	<3e8340490912292057g3e87eaabn115f85b78af2b08c@mail.gmail.com>
	<m1d41w62zc.fsf_-_@fess.ebiederm.org>
	<551280e50912300652r1007dee0j8de750bf33af9b3c@mail.gmail.com>
	<20091230183513.GC14493@us.ibm.com> <m1fx6suswz.fsf@fess.ebiederm.org>
	<20091230201712.GA23999@us.ibm.com>
	<m1hbr8tb8q.fsf_-_@fess.ebiederm.org>
	<20091230212931.233003b9@lxorguk.ukuu.org.uk>
From: ebiederm@xmission.com (Eric W. Biederman)
Date: Wed, 30 Dec 2009 13:36:57 -0800
In-Reply-To: <20091230212931.233003b9@lxorguk.ukuu.org.uk> (Alan Cox's message of "Wed\, 30 Dec 2009 21\:29\:31 +0000")
Message-ID: <m1skasrvnq.fsf@fess.ebiederm.org>
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Alan Cox <alan@lxorguk.ukuu.org.uk> writes:

>> Added bprm->nosuid to make remove the need to add
>> duplicate error prone checks.  This ensures that
>> the disabling of suid executables is exactly the
>> same as MNT_NOSUID.
>
> Another fine example of why we have security hooks so that we don't get a
> kernel full of other "random security idea of the day" hacks.

Well it comes from plan 9.  Except there they just simply did not
implement suid.  What causes you to think dropping the ability
to execute suid executables is a random security idea of the day?

Eric
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