Re: [PATCH 15/28] security: Introduce inode_post_removexattr hook

[Mimi Zohar]

Hi Roberto,

On Fri, 2023-03-03 at 19:18 +0100, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> 
> In preparation for moving IMA and EVM to the LSM infrastructure, introduce
> the inode_post_removexattr hook.
> 
> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> ---
>  fs/xattr.c                    |  1 +
>  include/linux/lsm_hook_defs.h |  2 ++
>  include/linux/security.h      |  5 +++++
>  security/security.c           | 14 ++++++++++++++
>  4 files changed, 22 insertions(+)
> 
> diff --git a/fs/xattr.c b/fs/xattr.c
> index 14a7eb3c8fa..10c959d9fc6 100644
> --- a/fs/xattr.c
> +++ b/fs/xattr.c
> @@ -534,6 +534,7 @@ __vfs_removexattr_locked(struct mnt_idmap *idmap,
>  
>  	if (!error) {
>  		fsnotify_xattr(dentry);
> +		security_inode_post_removexattr(dentry, name);
>  		evm_inode_post_removexattr(dentry, name);
>  	}

Nothing wrong with this, but other places in this function test "if
(error) goto ...".   Perhaps it is time to clean this up.

>  
> diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
> index eedefbcdde3..2ae5224d967 100644
> --- a/include/linux/lsm_hook_defs.h
> +++ b/include/linux/lsm_hook_defs.h
> @@ -147,6 +147,8 @@ LSM_HOOK(int, 0, inode_getxattr, struct dentry *dentry, const char *name)
>  LSM_HOOK(int, 0, inode_listxattr, struct dentry *dentry)
>  LSM_HOOK(int, 0, inode_removexattr, struct mnt_idmap *idmap,
>  	 struct dentry *dentry, const char *name)
> +LSM_HOOK(void, LSM_RET_VOID, inode_post_removexattr, struct dentry *dentry,
> +	 const char *name)

@Christian should the security_inode_removexattr() and
security_inode_post_removexattr() arguments be the same?

>  LSM_HOOK(int, 0, inode_set_acl, struct mnt_idmap *idmap,
>  	 struct dentry *dentry, const char *acl_name, struct posix_acl *kacl)
>  LSM_HOOK(int, 0, inode_get_acl, struct mnt_idmap *idmap,

-- 
thanks,

Mimi