From: Stephen Smalley <sds@tycho.nsa.gov>
To: Seth Forshee <seth.forshee@canonical.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Paul Moore <paul@paul-moore.com>,
Eric Paris <eparis@parisplace.org>
Cc: Serge Hallyn <serge.hallyn@canonical.com>,
James Morris <james.l.morris@oracle.com>,
linux-kernel@vger.kernel.org,
Andy Lutomirski <luto@amacapital.net>,
linux-security-module@vger.kernel.org, selinux@tycho.nsa.gov,
linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 6/7] selinux: Ignore security labels on user namespace mounts
Date: Thu, 16 Jul 2015 09:23:33 -0400 [thread overview]
Message-ID: <55A7B055.4050809@tycho.nsa.gov> (raw)
In-Reply-To: <1436989569-69582-7-git-send-email-seth.forshee@canonical.com>
On 07/15/2015 03:46 PM, Seth Forshee wrote:
> Unprivileged users should not be able to supply security labels
> in filesystems, nor should they be able to supply security
> contexts in unprivileged mounts. For any mount where s_user_ns is
> not init_user_ns, force the use of SECURITY_FS_USE_NONE behavior
> and return EPERM if any contexts are supplied in the mount
> options.
>
> Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
I think this is obsoleted by the subsequent discussion, but just for the
record: this patch would cause the files in the userns mount to be left
with the "unlabeled" label, and therefore under typical policies,
completely inaccessible to any process in a confined domain.
> ---
> security/selinux/hooks.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 459e71ddbc9d..eeb71e45ab82 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -732,6 +732,19 @@ static int selinux_set_mnt_opts(struct super_block *sb,
> !strcmp(sb->s_type->name, "pstore"))
> sbsec->flags |= SE_SBGENFS;
>
> + /*
> + * If this is a user namespace mount, no contexts are allowed
> + * on the command line and security labels mus be ignored.
> + */
> + if (sb->s_user_ns != &init_user_ns) {
> + if (context_sid || fscontext_sid || rootcontext_sid ||
> + defcontext_sid)
> + return -EPERM;
> + sbsec->behavior = SECURITY_FS_USE_NONE;
> + goto out_set_opts;
> + }
> +
> +
> if (!sbsec->behavior) {
> /*
> * Determine the labeling behavior to use for this
> @@ -813,6 +826,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
> sbsec->def_sid = defcontext_sid;
> }
>
> +out_set_opts:
> rc = sb_finish_set_opts(sb);
> out:
> mutex_unlock(&sbsec->lock);
>
next prev parent reply other threads:[~2015-07-16 13:24 UTC|newest]
Thread overview: 210+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-15 19:46 [PATCH 0/7] Initial support for user namespace owned mounts Seth Forshee
2015-07-15 19:46 ` Seth Forshee
2015-07-15 19:46 ` [PATCH 1/7] fs: Add user namesapace member to struct super_block Seth Forshee
2015-07-15 19:46 ` Seth Forshee
2015-07-16 2:47 ` Eric W. Biederman
2015-07-16 2:47 ` Eric W. Biederman
2015-08-05 21:03 ` Seth Forshee
2015-08-05 21:03 ` Seth Forshee
2015-08-05 21:19 ` Eric W. Biederman
2015-08-05 21:19 ` Eric W. Biederman
2015-08-06 14:20 ` Seth Forshee
2015-08-06 14:20 ` Seth Forshee
2015-08-06 14:51 ` Stephen Smalley
2015-08-06 14:51 ` Stephen Smalley
2015-08-06 15:44 ` Seth Forshee
2015-08-06 15:44 ` Seth Forshee
2015-08-06 16:11 ` Stephen Smalley
2015-08-06 16:11 ` Stephen Smalley
2015-08-07 14:16 ` Seth Forshee
2015-08-07 14:16 ` Seth Forshee
2015-08-07 14:32 ` Seth Forshee
2015-08-07 14:32 ` Seth Forshee
2015-08-07 18:35 ` Casey Schaufler
2015-08-07 18:35 ` Casey Schaufler
2015-08-07 18:57 ` Seth Forshee
2015-08-07 18:57 ` Seth Forshee
2015-07-15 19:46 ` [PATCH 2/7] userns: Simpilify MNT_NODEV handling Seth Forshee
2015-07-15 19:46 ` Seth Forshee
2015-07-15 19:46 ` [PATCH 3/7] fs: Ignore file caps in mounts from other user namespaces Seth Forshee
2015-07-15 19:46 ` Seth Forshee
2015-07-15 21:48 ` Serge E. Hallyn
2015-07-15 21:48 ` Serge E. Hallyn
2015-07-15 21:50 ` Andy Lutomirski
2015-07-15 21:50 ` Andy Lutomirski
2015-07-15 22:35 ` Eric W. Biederman
2015-07-15 22:35 ` Eric W. Biederman
2015-07-16 1:14 ` Seth Forshee
2015-07-16 1:14 ` Seth Forshee
2015-07-16 1:23 ` Andy Lutomirski
2015-07-16 1:23 ` Andy Lutomirski
2015-07-16 13:06 ` Seth Forshee
2015-07-16 13:06 ` Seth Forshee
2015-07-16 1:19 ` Andy Lutomirski
2015-07-16 1:19 ` Andy Lutomirski
2015-07-16 4:23 ` Eric W. Biederman
2015-07-16 4:23 ` Eric W. Biederman
2015-07-16 4:49 ` Andy Lutomirski
2015-07-16 4:49 ` Andy Lutomirski
2015-07-16 5:04 ` Eric W. Biederman
2015-07-16 5:04 ` Eric W. Biederman
2015-07-16 5:15 ` Andy Lutomirski
2015-07-16 5:15 ` Andy Lutomirski
2015-07-16 5:44 ` Eric W. Biederman
2015-07-16 5:44 ` Eric W. Biederman
2015-07-16 13:13 ` Seth Forshee
2015-07-16 13:13 ` Seth Forshee
2015-07-17 0:43 ` Eric W. Biederman
2015-07-17 0:43 ` Eric W. Biederman
2015-07-29 16:04 ` Serge E. Hallyn
2015-07-29 16:04 ` Serge E. Hallyn
2015-07-29 16:18 ` Serge E. Hallyn
2015-07-29 16:18 ` Serge E. Hallyn
2015-07-15 19:46 ` [PATCH 4/7] fs: Treat foreign mounts as nosuid Seth Forshee
2015-07-15 19:46 ` Seth Forshee
2015-07-17 6:46 ` Nikolay Borisov
2015-07-17 6:46 ` Nikolay Borisov
2015-07-15 19:46 ` [PATCH 5/7] security: Restrict security attribute updates for userns mounts Seth Forshee
2015-07-15 19:46 ` Seth Forshee
2015-07-15 19:46 ` [PATCH 6/7] selinux: Ignore security labels on user namespace mounts Seth Forshee
2015-07-15 19:46 ` Seth Forshee
2015-07-16 13:23 ` Stephen Smalley [this message]
2015-07-22 16:02 ` Stephen Smalley
2015-07-22 16:14 ` Seth Forshee
2015-07-22 16:14 ` Seth Forshee
2015-07-22 20:25 ` Stephen Smalley
2015-07-22 20:25 ` Stephen Smalley
2015-07-22 20:40 ` Stephen Smalley
2015-07-22 20:40 ` Stephen Smalley
2015-07-23 13:57 ` Stephen Smalley
2015-07-23 13:57 ` Stephen Smalley
2015-07-23 14:39 ` Seth Forshee
2015-07-23 14:39 ` Seth Forshee
2015-07-23 15:36 ` Stephen Smalley
2015-07-23 15:36 ` Stephen Smalley
2015-07-23 16:23 ` Seth Forshee
2015-07-23 16:23 ` Seth Forshee
2015-07-24 15:11 ` Seth Forshee
2015-07-24 15:11 ` Seth Forshee
2015-07-30 15:57 ` Stephen Smalley
2015-07-30 15:57 ` Stephen Smalley
2015-07-30 16:24 ` Seth Forshee
2015-07-30 16:24 ` Seth Forshee
2015-07-15 19:46 ` [PATCH 7/7] smack: Don't use security labels for " Seth Forshee
2015-07-15 19:46 ` Seth Forshee
2015-07-15 20:43 ` Casey Schaufler
2015-07-15 20:43 ` Casey Schaufler
2015-07-15 20:36 ` [PATCH 0/7] Initial support for user namespace owned mounts Casey Schaufler
2015-07-15 20:36 ` Casey Schaufler
2015-07-15 21:06 ` Eric W. Biederman
2015-07-15 21:06 ` Eric W. Biederman
2015-07-15 21:48 ` Seth Forshee
2015-07-15 21:48 ` Seth Forshee
2015-07-15 22:28 ` Eric W. Biederman
2015-07-15 22:28 ` Eric W. Biederman
2015-07-16 1:05 ` Andy Lutomirski
2015-07-16 1:05 ` Andy Lutomirski
2015-07-16 2:20 ` Eric W. Biederman
2015-07-16 2:20 ` Eric W. Biederman
2015-07-16 13:12 ` Stephen Smalley
2015-07-16 13:12 ` Stephen Smalley
2015-07-15 23:04 ` Casey Schaufler
2015-07-15 23:04 ` Casey Schaufler
2015-07-15 22:39 ` Casey Schaufler
2015-07-15 22:39 ` Casey Schaufler
2015-07-16 1:08 ` Andy Lutomirski
2015-07-16 1:08 ` Andy Lutomirski
2015-07-16 2:54 ` Casey Schaufler
2015-07-16 2:54 ` Casey Schaufler
2015-07-16 4:47 ` Eric W. Biederman
2015-07-16 4:47 ` Eric W. Biederman
2015-07-17 0:09 ` Dave Chinner
2015-07-17 0:09 ` Dave Chinner
2015-07-17 0:42 ` Eric W. Biederman
2015-07-17 0:42 ` Eric W. Biederman
2015-07-17 2:47 ` Dave Chinner
2015-07-17 2:47 ` Dave Chinner
2015-07-21 17:37 ` J. Bruce Fields
2015-07-21 17:37 ` J. Bruce Fields
2015-07-22 7:56 ` Dave Chinner
2015-07-22 7:56 ` Dave Chinner
2015-07-22 14:09 ` J. Bruce Fields
2015-07-22 14:09 ` J. Bruce Fields
2015-07-22 16:52 ` Austin S Hemmelgarn
2015-07-22 16:52 ` Austin S Hemmelgarn
2015-07-22 17:41 ` J. Bruce Fields
2015-07-22 17:41 ` J. Bruce Fields
2015-07-23 1:51 ` Dave Chinner
2015-07-23 1:51 ` Dave Chinner
2015-07-23 13:19 ` J. Bruce Fields
2015-07-23 13:19 ` J. Bruce Fields
2015-07-23 23:48 ` Dave Chinner
2015-07-23 23:48 ` Dave Chinner
2015-07-18 0:07 ` Serge E. Hallyn
2015-07-18 0:07 ` Serge E. Hallyn
2015-07-20 17:54 ` Colin Walters
2015-07-20 17:54 ` Colin Walters
2015-07-16 11:16 ` Lukasz Pawelczyk
2015-07-16 11:16 ` Lukasz Pawelczyk
2015-07-17 0:10 ` Eric W. Biederman
2015-07-17 0:10 ` Eric W. Biederman
2015-07-17 10:13 ` Lukasz Pawelczyk
2015-07-17 10:13 ` Lukasz Pawelczyk
2015-07-16 3:15 ` Eric W. Biederman
2015-07-16 3:15 ` Eric W. Biederman
2015-07-16 13:59 ` Seth Forshee
2015-07-16 13:59 ` Seth Forshee
2015-07-16 15:09 ` Casey Schaufler
2015-07-16 15:09 ` Casey Schaufler
2015-07-16 18:57 ` Seth Forshee
2015-07-16 18:57 ` Seth Forshee
2015-07-16 21:42 ` Casey Schaufler
2015-07-16 21:42 ` Casey Schaufler
2015-07-16 22:27 ` Andy Lutomirski
2015-07-16 22:27 ` Andy Lutomirski
2015-07-16 23:08 ` Casey Schaufler
2015-07-16 23:08 ` Casey Schaufler
2015-07-16 23:29 ` Andy Lutomirski
2015-07-16 23:29 ` Andy Lutomirski
2015-07-17 0:45 ` Casey Schaufler
2015-07-17 0:45 ` Casey Schaufler
2015-07-17 0:59 ` Andy Lutomirski
2015-07-17 0:59 ` Andy Lutomirski
2015-07-17 14:28 ` Serge E. Hallyn
2015-07-17 14:28 ` Serge E. Hallyn
2015-07-17 14:56 ` Seth Forshee
2015-07-17 14:56 ` Seth Forshee
2015-07-21 20:35 ` Seth Forshee
2015-07-21 20:35 ` Seth Forshee
2015-07-22 1:52 ` Casey Schaufler
2015-07-22 1:52 ` Casey Schaufler
2015-07-22 15:56 ` Seth Forshee
2015-07-22 15:56 ` Seth Forshee
2015-07-22 18:10 ` Casey Schaufler
2015-07-22 18:10 ` Casey Schaufler
2015-07-22 19:32 ` Seth Forshee
2015-07-22 19:32 ` Seth Forshee
2015-07-23 0:05 ` Casey Schaufler
2015-07-23 0:05 ` Casey Schaufler
2015-07-23 0:15 ` Eric W. Biederman
2015-07-23 0:15 ` Eric W. Biederman
2015-07-23 5:15 ` Seth Forshee
2015-07-23 5:15 ` Seth Forshee
2015-07-23 21:48 ` Casey Schaufler
2015-07-23 21:48 ` Casey Schaufler
2015-07-28 20:40 ` Seth Forshee
2015-07-28 20:40 ` Seth Forshee
2015-07-30 16:18 ` Casey Schaufler
2015-07-30 16:18 ` Casey Schaufler
2015-07-30 17:05 ` Eric W. Biederman
2015-07-30 17:05 ` Eric W. Biederman
2015-07-30 17:25 ` Seth Forshee
2015-07-30 17:25 ` Seth Forshee
2015-07-30 17:33 ` Eric W. Biederman
2015-07-30 17:33 ` Eric W. Biederman
2015-07-17 13:21 ` Seth Forshee
2015-07-17 13:21 ` Seth Forshee
2015-07-17 17:14 ` Casey Schaufler
2015-07-17 17:14 ` Casey Schaufler
2015-07-16 15:59 ` Seth Forshee
2015-07-16 15:59 ` Seth Forshee
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