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

[Paul Moore]

On Jan 15, 2024 Roberto Sassu <roberto.sassu at huaweicloud.com> wrote:
> 
> 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 +++++----
>  include/linux/lsm_hook_defs.h |  2 ++
>  include/linux/security.h      |  5 +++++
>  security/security.c           | 14 ++++++++++++++
>  4 files changed, 26 insertions(+), 4 deletions(-)

Acked-by: Paul Moore <paul at paul-moore.com>

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