Received-SPF: pass (google.com: domain of linux-nfs+bounces-1896-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:4601:e00::3 as permitted sender) client-ip=2604:1380:4601:e00::3;
Message-ID: <2d2a9e48-543a-4307-8de6-2e44b1ead7c5@linux.ibm.com>
Date: Mon, 12 Feb 2024 12:45:47 -0500
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v9 20/25] ima: Move to LSM infrastructure
Content-Language: en-US
To: Roberto Sassu <roberto.sassu@huaweicloud.com>, viro@zeniv.linux.org.uk,
        brauner@kernel.org, chuck.lever@oracle.com, jlayton@kernel.org,
        neilb@suse.de, kolga@netapp.com, Dai.Ngo@oracle.com, tom@talpey.com,
        paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com,
        zohar@linux.ibm.com, dmitry.kasatkin@gmail.com,
        eric.snowberg@oracle.com, dhowells@redhat.com, jarkko@kernel.org,
        stephen.smalley.work@gmail.com, eparis@parisplace.org,
        casey@schaufler-ca.com, shuah@kernel.org, mic@digikod.net
Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
        linux-nfs@vger.kernel.org, linux-security-module@vger.kernel.org,
        linux-integrity@vger.kernel.org, keyrings@vger.kernel.org,
        selinux@vger.kernel.org, linux-kselftest@vger.kernel.org,
        Roberto Sassu <roberto.sassu@huawei.com>
References: <20240115181809.885385-1-roberto.sassu@huaweicloud.com>
 <20240115181809.885385-21-roberto.sassu@huaweicloud.com>
From: Stefan Berger <stefanb@linux.ibm.com>
In-Reply-To: <20240115181809.885385-21-roberto.sassu@huaweicloud.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit


On 1/15/24 13:18, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
> 
> Move hardcoded IMA function calls (not appraisal-specific functions) from
> various places in the kernel to the LSM infrastructure, by introducing a
> new LSM named 'ima' (at the end of the LSM list and always enabled like
> 'integrity').
> 
> Having IMA before EVM in the Makefile is sufficient to preserve the
> relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM,
> and thus the order of IMA and EVM function calls as when they were
> hardcoded.
> 
> Make moved functions as static (except ima_post_key_create_or_update(),
> which is not in ima_main.c), and register them as implementation of the
> respective hooks in the new function init_ima_lsm().
> 
> Select CONFIG_SECURITY_PATH, to ensure that the path-based LSM hook
> path_post_mknod is always available and ima_post_path_mknod() is always
> executed to mark files as new, as before the move.
> 
> A slight difference is that IMA and EVM functions registered for the
> inode_post_setattr, inode_post_removexattr, path_post_mknod,
> inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl
> won't be executed for private inodes. Since those inodes are supposed to be
> fs-internal, they should not be of interest of IMA or EVM. The S_PRIVATE

of interest 'to'

> flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub
> and kernel-internal tmpfs files.
> 
> Conditionally register ima_post_key_create_or_update() if
> CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled. Also, conditionally register
> ima_kernel_module_request() if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is enabled.
> 
> Finally, add the LSM_ID_IMA case in lsm_list_modules_test.c.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
> Acked-by: Chuck Lever <chuck.lever@oracle.com>

Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>