Message-ID: <e5303185-c698-0243-8208-6cb553fde37b@linux.ibm.com>
Date:   Mon, 6 Mar 2023 14:24:51 -0500
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Subject: Re: [PATCH 16/28] security: Introduce file_post_open hook
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To:     Roberto Sassu <roberto.sassu@huaweicloud.com>,
        viro@zeniv.linux.org.uk, chuck.lever@oracle.com,
        jlayton@kernel.org, zohar@linux.ibm.com, dmitry.kasatkin@gmail.com,
        paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com,
        dhowells@redhat.com, jarkko@kernel.org,
        stephen.smalley.work@gmail.com, eparis@parisplace.org,
        casey@schaufler-ca.com, brauner@kernel.org
Cc:     linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org,
        linux-integrity@vger.kernel.org,
        linux-security-module@vger.kernel.org, keyrings@vger.kernel.org,
        selinux@vger.kernel.org, linux-kernel@vger.kernel.org,
        Roberto Sassu <roberto.sassu@huawei.com>
References: <20230303181842.1087717-1-roberto.sassu@huaweicloud.com>
 <20230303181842.1087717-17-roberto.sassu@huaweicloud.com>
From:   Stefan Berger <stefanb@linux.ibm.com>
In-Reply-To: <20230303181842.1087717-17-roberto.sassu@huaweicloud.com>
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On 3/3/23 13:18, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@huawei.com>
> 
> In preparation to move IMA and EVM to the LSM infrastructure, introduce the
> file_post_open hook. Also, export security_file_post_open() for NFS.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>

>   
> +/**
> + * security_file_post_open() - Recheck access to a file after it has been opened
> + * @file: the file
> + * @mask: access mask
> + *
> + * Recheck access with mask after the file has been opened. The hook is useful
> + * for LSMs that require the file content to be available in order to make
> + * decisions.
> + *
> + * Return: Returns 0 if permission is granted.
> + */
> +int security_file_post_open(struct file *file, int mask)
> +{

Files with private inodes don't seem to checked for in any existing functions, either, so no check. Good..

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

> +	return call_int_hook(file_post_open, 0, file, mask);
> +}
> +EXPORT_SYMBOL_GPL(security_file_post_open);
> +
>   /**
>    * security_file_truncate() - Check if truncating a file is allowed
>    * @file: file