[PATCH v9 11/25] security: Introduce inode_post_removexattr hook

[Christian Brauner]

On Mon, Jan 15, 2024 at 07:17:55PM +0100, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu at huawei.com>
> 
> In preparation for moving IMA and EVM to the LSM infrastructure, introduce
> the inode_post_removexattr hook.
> 
> At inode_removexattr hook, EVM verifies the file's existing HMAC value. At
> inode_post_removexattr, EVM re-calculates the file's HMAC with the passed
> xattr removed and other file metadata.
> 
> Other LSMs could similarly take some action after successful xattr removal.
> 
> The new hook cannot return an error and cannot cause the operation to be
> reverted.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>
> Reviewed-by: Stefan Berger <stefanb at linux.ibm.com>
> Reviewed-by: Mimi Zohar <zohar at linux.ibm.com>
> Reviewed-by: Casey Schaufler <casey at schaufler-ca.com>
> ---
>  fs/xattr.c                    |  9 +++++----

Acked-by: Christian Brauner <brauner at kernel.org>