From: James Bottomley <jejb@linux.ibm.com>
To: Stefan Berger <stefanb@linux.ibm.com>, linux-integrity@vger.kernel.org
Cc: zohar@linux.ibm.com, serge@hallyn.com,
christian.brauner@ubuntu.com, containers@lists.linux.dev,
dmitry.kasatkin@gmail.com, ebiederm@xmission.com,
krzysztof.struczynski@huawei.com, roberto.sassu@huawei.com,
mpeters@redhat.com, lhinds@redhat.com, lsturman@redhat.com,
puiterwi@redhat.com, jamjoom@us.ibm.com,
linux-kernel@vger.kernel.org, paul@paul-moore.com,
rgb@redhat.com, linux-security-module@vger.kernel.org,
jmorris@namei.org
Subject: Re: [RFC 20/20] ima: Setup securityfs_ns for IMA namespace
Date: Wed, 01 Dec 2021 14:21:07 -0500 [thread overview]
Message-ID: <f5e3101e8dee2aa0064e7b68992afe0143e22058.camel@linux.ibm.com> (raw)
In-Reply-To: <f2113d60-49d3-2e2d-7dbe-b831035f96a1@linux.ibm.com>
On Wed, 2021-12-01 at 13:11 -0500, Stefan Berger wrote:
> On 12/1/21 12:56, James Bottomley wrote:
[...]
> I tried this with runc and a user namespace active mapping uid 1000
> on the host to uid 0 in the container. There I run into the problem
> that all of the files and directories without the above work-around
> are mapped to 'nobody', just like all the files in sysfs in this case
> are also mapped to nobody. This code resolved the issue.
So I applied your patches with the permission shift commented out and
instrumented inode_alloc() to see where it might be failing and I
actually find it all works as expected for me:
ejb@testdeb:~> unshare -r --user --mount --ima
root@testdeb:~# mount -t securityfs_ns none /sys/kernel/security
root@testdeb:~# ls -l /sys/kernel/security/ima/
total 0
-r--r----- 1 root root 0 Dec 1 19:11 ascii_runtime_measurements
-r--r----- 1 root root 0 Dec 1 19:11 binary_runtime_measurements
-rw------- 1 root root 0 Dec 1 19:11 policy
-r--r----- 1 root root 0 Dec 1 19:11 runtime_measurements_count
-r--r----- 1 root root 0 Dec 1 19:11 violations
I think your problem is something to do with how runc is installing the
uid/gid mappings. If it's installing them after the security_ns inodes
are created then they get the -1 value (because no mappings exist in
s_user_ns). I can even demonstrate this by forcing unshare to enter
the IMA namespace before writing the mapping values and I'll see
"nobody nogroup" above like you do.
I also see the instrumentation telling me that i_write_uid() is mapping
back to 1000 in the former case and -1 in the latter.
James
next prev parent reply other threads:[~2021-12-01 19:21 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-30 16:06 [RFC 00/20] ima: Namespace IMA with audit support in IMA-ns Stefan Berger
2021-11-30 16:06 ` [RFC 01/20] ima: Add IMA namespace support Stefan Berger
2021-11-30 16:06 ` [RFC 02/20] ima: Define ns_status for storing namespaced iint data Stefan Berger
2021-11-30 16:06 ` [RFC 03/20] ima: Namespace audit status flags Stefan Berger
2021-11-30 16:06 ` [RFC 04/20] ima: Move delayed work queue and variables into ima_namespace Stefan Berger
2021-11-30 16:06 ` [RFC 05/20] ima: Move IMA's keys queue related " Stefan Berger
2021-11-30 16:06 ` [RFC 06/20] ima: Move policy " Stefan Berger
2021-11-30 16:06 ` [RFC 07/20] ima: Move ima_htable " Stefan Berger
2021-11-30 16:06 ` [RFC 08/20] ima: Move measurement list related variables " Stefan Berger
2021-12-02 12:46 ` James Bottomley
2021-12-02 13:41 ` Stefan Berger
2021-12-02 16:29 ` James Bottomley
2021-12-02 16:45 ` Stefan Berger
2021-12-02 17:44 ` James Bottomley
2021-12-02 18:03 ` Stefan Berger
2021-12-02 20:03 ` James Bottomley
2021-11-30 16:06 ` [RFC 09/20] ima: Only accept AUDIT rules for IMA non-init_ima_ns namespaces for now Stefan Berger
2021-11-30 16:06 ` [RFC 10/20] ima: Implement hierarchical processing of file accesses Stefan Berger
2021-11-30 16:06 ` [RFC 11/20] securityfs: Prefix global variables with securityfs_ Stefan Berger
2021-11-30 16:06 ` [RFC 12/20] securityfs: Pass static variables as parameters from top level functions Stefan Berger
2021-11-30 16:06 ` [RFC 13/20] securityfs: Build securityfs_ns for namespacing support Stefan Berger
2021-12-02 13:35 ` Christian Brauner
2021-12-02 13:47 ` Stefan Berger
2021-11-30 16:06 ` [RFC 14/20] ima: Move some IMA policy and filesystem related variables into ima_namespace Stefan Berger
2021-11-30 16:06 ` [RFC 15/20] capabilities: Introduce CAP_INTEGRITY_ADMIN Stefan Berger
2021-11-30 17:27 ` Casey Schaufler
2021-11-30 17:41 ` Stefan Berger
2021-11-30 17:50 ` Casey Schaufler
2021-11-30 16:06 ` [RFC 16/20] ima: Use ns_capable() for namespace policy access Stefan Berger
2021-11-30 16:06 ` [RFC 17/20] ima: Use integrity_admin_ns_capable() to check corresponding capability Stefan Berger
2021-12-01 16:58 ` James Bottomley
2021-12-01 17:35 ` Stefan Berger
2021-12-01 19:29 ` James Bottomley
2021-12-02 7:16 ` Denis Semakin
2021-12-02 12:33 ` James Bottomley
2021-12-02 17:54 ` Stefan Berger
2021-12-02 12:59 ` Christian Brauner
2021-12-02 13:01 ` Christian Brauner
2021-12-02 15:58 ` Casey Schaufler
2021-11-30 16:06 ` [RFC 18/20] userns: Introduce a refcount variable for calling early teardown function Stefan Berger
2021-11-30 16:06 ` [RFC 19/20] ima/userns: Define early teardown function for IMA namespace Stefan Berger
2021-11-30 16:06 ` [RFC 20/20] ima: Setup securityfs_ns " Stefan Berger
2021-12-01 17:56 ` James Bottomley
2021-12-01 18:11 ` Stefan Berger
2021-12-01 19:21 ` James Bottomley [this message]
2021-12-01 20:25 ` Stefan Berger
2021-12-01 21:11 ` James Bottomley
2021-12-01 21:34 ` Stefan Berger
2021-12-01 22:01 ` James Bottomley
2021-12-01 22:09 ` Stefan Berger
2021-12-01 22:19 ` James Bottomley
2021-12-02 0:02 ` Stefan Berger
2021-12-02 13:18 ` Christian Brauner
2021-12-02 13:52 ` Stefan Berger
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