Re: [PATCH v1 3/8] LSM: Identify the process attributes for each module

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Oct 25, 2022 at 11:45:14AM -0700, Casey Schaufler wrote:
> Add an integer member "features" to the struct lsm_id which
> identifies the API related data associated with each security
> module. The initial set of features maps to information that
> has traditionaly been available in /proc/self/attr.
> 
> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
> ---
>  include/linux/lsm_hooks.h  |  1 +
>  include/uapi/linux/lsm.h   | 14 ++++++++++++++
>  security/apparmor/lsm.c    |  1 +
>  security/selinux/hooks.c   |  2 ++
>  security/smack/smack_lsm.c |  1 +
>  5 files changed, 19 insertions(+)
> 
> diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
> index dd4b4d95a172..46b2aa6a677e 100644
> --- a/include/linux/lsm_hooks.h
> +++ b/include/linux/lsm_hooks.h
> @@ -1608,6 +1608,7 @@ struct security_hook_heads {
>  struct lsm_id {
>  	const char	*lsm;		/* Name of the LSM */
>  	int		id;		/* LSM ID */
> +	int		features;	/* Set of LSM features */

Again, be explicit about size please.  And documentation.

>  };
>  
>  /*
> diff --git a/include/uapi/linux/lsm.h b/include/uapi/linux/lsm.h
> index d5bcbb9375df..61e13b1b9ece 100644
> --- a/include/uapi/linux/lsm.h
> +++ b/include/uapi/linux/lsm.h
> @@ -29,4 +29,18 @@
>  #define LSM_ID_BPF		42
>  #define LSM_ID_LANDLOCK		43
>  
> +/*
> + * LSM_ATTR_XXX values identify the /proc/.../attr entry that the
> + * context represents. Not all security modules provide all of these
> + * values. Some security modules provide none of them.
> + */
> +/* clang-format off */

Why this comment?  That shouldn't be in uapi files.  Or any header
files.

> +#define LSM_ATTR_CURRENT	(1UL << 0)
> +#define LSM_ATTR_EXEC		(1UL << 1)
> +#define LSM_ATTR_FSCREATE	(1UL << 2)
> +#define LSM_ATTR_KEYCREATE	(1UL << 3)
> +#define LSM_ATTR_PREV		(1UL << 4)
> +#define LSM_ATTR_SOCKCREATE	(1UL << 5)
> +/* clang-format on */

Again, please drop.

Where is it documented what these attributes actually mean?

thanks,

greg k-h