linux-kernel - Re: [RFC] cgroups: implement device whitelist lsm (v2)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <6599ad830803140216k1a04ce4ej4779bf10ec6ef4f9@mail.gmail.com>
Date:	Fri, 14 Mar 2008 02:16:46 -0700
From:	"Paul Menage" <menage@...gle.com>
To:	"Serge E. Hallyn" <serue@...ibm.com>
Cc:	lkml <linux-kernel@...r.kernel.org>,
	linux-security-module@...r.kernel.org, "Greg KH" <greg@...ah.com>,
	"Stephen Smalley" <sds@...ch.ncsc.mil>,
	"Casey Schaufler" <casey@...aufler-ca.com>,
	"Pavel Emelianov" <xemul@...nvz.org>
Subject: Re: [RFC] cgroups: implement device whitelist lsm (v2)

On Wed, Mar 12, 2008 at 8:27 PM, Serge E. Hallyn <serue@...ibm.com> wrote:
>
>  While composing this with the ns_cgroup may seem logical, it is not
>  the right thing to do, because updates to /cg/cg1/devcg.deny are
>  not reflected in /cg/cg1/cg2/devcg.allow.

Maybe you should follow up the tree to ensure that all parent groups
have access to the device too? Or alternatively, cache the results of
this lookup whenever permissions for a device change?

>
>  A task may only be moved to another devcgroup if it is moving to
>  a direct descendent of its current devcgroup.

What's the rationale for that?

>
>  CAP_NS_OVERRIDE is defined as the capability needed to cross namespaces.
>  A task needs both CAP_NS_OVERRIDE and CAP_SYS_ADMIN to create a new
>  devcgroup, update a devcgroup's access, or move a task to a new
>  devcgroup.

But this isn't necessarily crossing namespaces. It could be used for
device control in the same namespace (e.g. allowing a job to access a
raw disk for its data storage rather than going through the
filesystem).

Paul
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/