Re: [PATCH v3 01/25] ima: Align ima_inode_post_setattr() definition with LSM infrastructure

[Mimi Zohar]

On Mon, 2023-09-04 at 15:33 +0200, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> 
> Change ima_inode_post_setattr() definition, so that it can be registered as
> implementation of the inode_post_setattr hook.

Please indicate inode_post_settattr() is a new hook.  In general it
should be stated on first usage.  In 02/25 the wording "(to be
introduced)" is used, but not on first usage.  Please add "(to be
introduced)" after inode_post_setattr.

Adding a new security hook argument would be to support both IMA and
EVM, which have different options.

Mimi

> Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
> Reviewed-by: Stefan Berger <stefanb@xxxxxxxxxxxxx>
> ---
>  fs/attr.c                             | 2 +-
>  include/linux/ima.h                   | 4 ++--
>  security/integrity/ima/ima_appraise.c | 3 ++-
>  3 files changed, 5 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/attr.c b/fs/attr.c
> index d60dc1edb526..7d4553c1208d 100644
> --- a/fs/attr.c
> +++ b/fs/attr.c
> @@ -486,7 +486,7 @@ int notify_change(struct mnt_idmap *idmap, struct dentry *dentry,
>  
>  	if (!error) {
>  		fsnotify_change(dentry, ia_valid);
> -		ima_inode_post_setattr(idmap, dentry);
> +		ima_inode_post_setattr(idmap, dentry, ia_valid);
>  		evm_inode_post_setattr(dentry, ia_valid);
>  	}
>  
> diff --git a/include/linux/ima.h b/include/linux/ima.h
> index 86b57757c7b1..910a2f11a906 100644
> --- a/include/linux/ima.h
> +++ b/include/linux/ima.h
> @@ -186,7 +186,7 @@ static inline void ima_post_key_create_or_update(struct key *keyring,
>  #ifdef CONFIG_IMA_APPRAISE
>  extern bool is_ima_appraise_enabled(void);
>  extern void ima_inode_post_setattr(struct mnt_idmap *idmap,
> -				   struct dentry *dentry);
> +				   struct dentry *dentry, int ia_valid);
>  extern int ima_inode_setxattr(struct dentry *dentry, const char *xattr_name,
>  		       const void *xattr_value, size_t xattr_value_len);
>  extern int ima_inode_set_acl(struct mnt_idmap *idmap,
> @@ -206,7 +206,7 @@ static inline bool is_ima_appraise_enabled(void)
>  }
>  h
>  static inline void ima_inode_post_setattr(struct mnt_idmap *idmap,
> -					  struct dentry *dentry)
> +					  struct dentry *dentry, int ia_valid)
>  {
>  	return;
>  }
> diff --git a/security/integrity/ima/ima_appraise.c b/security/integrity/ima/ima_appraise.c
> index 491c1aca0b1c..6b032bce4fe7 100644
> --- a/security/integrity/ima/ima_appraise.c
> +++ b/security/integrity/ima/ima_appraise.c
> @@ -627,6 +627,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
>   * ima_inode_post_setattr - reflect file metadata changes
>   * @idmap:  idmap of the mount the inode was found from
>   * @dentry: pointer to the affected dentry
> + * @ia_valid: for the UID and GID status
>   *
>   * Changes to a dentry's metadata might result in needing to appraise.
>   *
> @@ -634,7 +635,7 @@ void ima_update_xattr(struct integrity_iint_cache *iint, struct file *file)
>   * to lock the inode's i_mutex.
>   */
>  void ima_inode_post_setattr(struct mnt_idmap *idmap,
> -			    struct dentry *dentry)
> +			    struct dentry *dentry, int ia_valid)
>  {
>  	struct inode *inode = d_backing_inode(dentry);
>  	struct integrity_iint_cache *iint;