[PATCH 16/28] security: Introduce file_post_open hook

[Stefan Berger]

On 3/3/23 13:18, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu at 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 at 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 at 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