[RFC PATCH 1/4] lsm: separate security_task_getsecid() into subjective and objective variants

[Mimi Zohar]

On Fri, 2021-02-19 at 18:29 -0500, Paul Moore wrote:
> Of the three LSMs that implement the security_task_getsecid() LSM
> hook, all three LSMs provide the task's objective security
> credentials.  This turns out to be unfortunate as most of the hook's
> callers seem to expect the task's subjective credentials, although
> a small handful of callers do correctly expect the objective
> credentials.
> 
> This patch is the first step towards fixing the problem: it splits
> the existing security_task_getsecid() hook into two variants, one
> for the subjective creds, one for the objective creds.
> 
>   void security_task_getsecid_subj(struct task_struct *p,
> 				   u32 *secid);
>   void security_task_getsecid_obj(struct task_struct *p,
> 				  u32 *secid);
> 
> While this patch does fix all of the callers to use the correct
> variant, in order to keep this patch focused on the callers and to
> ease review, the LSMs continue to use the same implementation for
> both hooks.  The net effect is that this patch should not change
> the behavior of the kernel in any way, it will be up to the latter
> LSM specific patches in this series to change the hook
> implementations and return the correct credentials.
> 
> Signed-off-by: Paul Moore <paul at paul-moore.com>

Thanks, Paul.

Acked-by: Mimi Zohar <zohar at linux.ibm.com>  (IMA)