From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W.Biederman" Subject: Re: [PATCH 2/2] groups: Allow unprivileged processes to use setgroups to drop groups Date: Mon, 17 Nov 2014 17:11:57 -0500 Message-ID: <0b65fd07-48ea-483b-8fd5-fd84d0bff881@email.android.com> References: <3ccec8a13019b5e8ce7b1d7889677b778b070dc8.1416041823.git.josh@joshtriplett.org> <0895c1f268bc0b01cc6c8ed4607d7c3953f49728.1416041823.git.josh@joshtriplett.org> <87d28osceg.fsf@x220.int.ebiederm.org> <20141115192924.GB19060@thin> <20141115202042.GA20900@thin> <20141116020511.GB5507@thunk.org> <6C690A2C-8EB1-421A-94C3-9803AFB95760@joshtriplett.org> <20141116034005.GC5507@thunk.org> <20141116045232.GB18880@thin> <20141117113734.396798e6@lxorguk.ukuu.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: Sender: linux-man-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Andy Lutomirski , One Thousand Gnomes Cc: linux-man , Ted Ts'o , Michael Kerrisk-manpages , Josh Triplett , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Andrew Morton , Linux API , Kees Cook List-Id: linux-api@vger.kernel.org On November 17, 2014 1:07:30 PM EST, Andy Lutomirski wrote: >On Nov 17, 2014 3:37 AM, "One Thousand Gnomes" > wrote: >> >> > optional), I can do that too. The security model of "having a >group >> > gives you less privilege than not having it" seems crazy, but >> > nonetheless I can see a couple of easy ways that we can avoid >breaking >> >> It's an old pattern of use that makes complete sense in a traditional >> Unix permission world because it's the only way to do "exclude >{list}" >> nicely. Our default IMHO shouldn't break this. >> >> > that pattern, no_new_privs being one of them. I'd like to make >sure >> > that nobody sees any other real-world corner case that unprivileged >> > setgroups would break. >> >> Barring the usual risk of people doing improper error checking I >don't >> see one immediately. >> >> For containers I think it actually makes sense that the sysctl can be >> applied per container anyway. > >We'll probably need per container sysctls some day. We already have a mess of per network namespace sysctls, as well as few for other namespaces. We have the infrastructure it is just a matter of using it for whatever purpose we need. Eric -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html