From: Serge Hallyn <serge.hallyn@canonical.com>
To: Bastian Blank <bastian@waldi.eu.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
containers@lists.linux-foundation.org,
kernel list <linux-kernel@vger.kernel.org>,
LSM <linux-security-module@vger.kernel.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Kees Cook <kees.cook@canonical.com>,
Alexey Dobriyan <adobriyan@gmail.com>,
Michael Kerrisk <mtk.manpages@gmail.com>
Subject: Re: [PATCH 6/7] user namespaces: convert all capable checks in kernel/sys.c
Date: Mon, 10 Jan 2011 16:56:42 -0600 [thread overview]
Message-ID: <20110110225642.GB18944@localhost> (raw)
In-Reply-To: <20110110215937.GB21351@wavehammer.waldi.eu.org>
Quoting Bastian Blank (bastian@waldi.eu.org):
> On Mon, Jan 10, 2011 at 09:14:07PM +0000, Serge E. Hallyn wrote:
> > - if (pcred->uid != cred->euid &&
> > - pcred->euid != cred->euid && !capable(CAP_SYS_NICE)) {
> > + if (pcred->user->user_ns != cred->user->user_ns &&
> > + pcred->uid != cred->euid &&
> > + pcred->euid != cred->euid &&
> > + !ns_capable(pcred->user->user_ns, CAP_SYS_NICE)) {
>
> I don't think this is correct. This would not error out if the both
> userns are the same. Because the same patern (check uid if same userns,
> otherwise only capability) shows up in several parts of the code, maybe
> this should be factored out.
Yes, I'm really not sure what I was thinking here. Thanks!
> > @@ -496,7 +498,7 @@ SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid)
> > if (rgid != (gid_t) -1) {
> > if (old->gid == rgid ||
> > old->egid == rgid ||
> > - capable(CAP_SETGID))
> > + ns_capable(current_user_ns(), CAP_SETGID))
>
> Would it not possible to add another function (nsown_capable?) that
> checks against the own userns?
Good idea, I'll add that one.
thanks,
-serge
next prev parent reply other threads:[~2011-01-10 22:56 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-10 21:11 userns: targeted capabilities v3 Serge E. Hallyn
2011-01-10 21:13 ` [PATCH 1/7] Add a user_namespace as creator/owner of uts_namespace Serge E. Hallyn
2011-01-10 21:13 ` [PATCH 2/7] security: Make capabilities relative to the user namespace Serge E. Hallyn
2011-01-10 21:13 ` [PATCH 3/7] allow sethostname in a container Serge E. Hallyn
2011-01-10 21:13 ` [PATCH 4/7] allow killing tasks in your own or child userns Serge E. Hallyn
2011-01-10 21:52 ` Bastian Blank
2011-01-10 22:51 ` Serge Hallyn
2011-01-10 23:23 ` Bastian Blank
2011-01-11 1:31 ` Serge E. Hallyn
2011-01-14 14:50 ` Bastian Blank
2011-01-15 0:31 ` Serge E. Hallyn
2011-01-15 11:30 ` Bastian Blank
2011-01-15 14:12 ` Serge E. Hallyn
2011-01-11 4:22 ` Oren Laadan
2011-01-11 4:32 ` Serge E. Hallyn
2011-01-10 21:13 ` [PATCH 5/7] Allow ptrace from non-init user namespaces Serge E. Hallyn
2011-01-10 21:14 ` [PATCH 6/7] user namespaces: convert all capable checks in kernel/sys.c Serge E. Hallyn
2011-01-10 21:59 ` Bastian Blank
2011-01-10 22:56 ` Serge Hallyn [this message]
2011-01-11 5:27 ` Serge E. Hallyn
2011-01-14 15:02 ` Bastian Blank
2011-01-10 21:14 ` [PATCH 7/7] user namespaces: convert several capable() calls Serge E. Hallyn
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