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Message-ID: <4186a81dd0b4608b484d95ffbe7b1c026e648e36.camel@linux.ibm.com>
Subject: Re: [PATCH v10 10/27] ima: Move IMA securityfs files into
 ima_namespace or onto stack
From:   Mimi Zohar <zohar@linux.ibm.com>
To:     Stefan Berger <stefanb@linux.ibm.com>,
        linux-integrity@vger.kernel.org
Cc:     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, jejb@linux.ibm.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,
        Christian Brauner <brauner@kernel.org>
Date:   Thu, 17 Feb 2022 09:44:40 -0500
In-Reply-To: <20220201203735.164593-11-stefanb@linux.ibm.com>
References: <20220201203735.164593-1-stefanb@linux.ibm.com>
         <20220201203735.164593-11-stefanb@linux.ibm.com>
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On Tue, 2022-02-01 at 15:37 -0500, Stefan Berger wrote:
> Earlier we simplified how dentry creation and deletion is manged in
> securityfs. This allows us to move IMA securityfs files from global
> variables directly into ima_fs_ns_init() itself. We can now rely on
> those dentries to be cleaned up when the securityfs instance is cleaned
> when the last reference to it is dropped.
> 
> Things are slightly different for the initial IMA namespace. In contrast
> to non-initial IMA namespaces it has pinning logic binding the lifetime
> of the securityfs superblock to created dentries. We need to keep this
> behavior to not regress userspace. Since IMA never removes most of the
> securityfs files the initial securityfs instance stays pinned. This also
> means even for the initial IMA namespace we don't need to keep
> references to these dentries anywhere.
> 
> The ima_policy file is the exception since IMA can end up removing it
> on systems that don't allow reading or extending the IMA custom policy.
> 
> Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
> Acked-by: Christian Brauner <brauner@kernel.org>

Really nicely worded patch description.  Thanks!

Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>