Re: [PATCH 10/11] selinux: Implement the watch_key security hook [ver #7]

[Stephen Smalley <sds@xxxxxxxxxxxxx>]

On 8/30/19 10:41 AM, David Howells wrote:
> How about the attached instead, then?

Works for me.

> David
> ---
> commit 00444a695b35c602230ac2cabb4f1d7e94e3966d
> Author: David Howells <dhowells@xxxxxxxxxx>
> Date:   Thu Aug 29 17:01:34 2019 +0100
>
>      selinux: Implement the watch_key security hook
>      
>      Implement the watch_key security hook to make sure that a key grants the
>      caller View permission in order to set a watch on a key.
>      
>      For the moment, the watch_devices security hook is left unimplemented as
>      it's not obvious what the object should be since the queue is global and
>      didn't previously exist.
>      
>      Signed-off-by: David Howells <dhowells@xxxxxxxxxx>

Acked-by: Stephen Smalley <sds@xxxxxxxxxxxxx>

> diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> index 74dd46de01b6..88df06969bed 100644
> --- a/security/selinux/hooks.c
> +++ b/security/selinux/hooks.c
> @@ -6533,6 +6533,17 @@ static int selinux_key_getsecurity(struct key *key, char **_buffer)
>   	*_buffer = context;
>   	return rc;
>   }
> +
> +#ifdef CONFIG_KEY_NOTIFICATIONS
> +static int selinux_watch_key(struct key *key)
> +{
> +	struct key_security_struct *ksec = key->security;
> +	u32 sid = current_sid();
> +
> +	return avc_has_perm(&selinux_state,
> +			    sid, ksec->sid, SECCLASS_KEY, KEY_NEED_VIEW, NULL);
> +}
> +#endif
>   #endif
>   
>   #ifdef CONFIG_SECURITY_INFINIBAND
> @@ -6965,6 +6976,9 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
>   	LSM_HOOK_INIT(key_free, selinux_key_free),
>   	LSM_HOOK_INIT(key_permission, selinux_key_permission),
>   	LSM_HOOK_INIT(key_getsecurity, selinux_key_getsecurity),
> +#ifdef CONFIG_KEY_NOTIFICATIONS
> +	LSM_HOOK_INIT(watch_key, selinux_watch_key),
> +#endif
>   #endif
>   
>   #ifdef CONFIG_AUDIT