[PATCH v4 1/3] security: Introduce LSM_ORDER_LAST and set it for the integrity LSM

[Mimi Zohar]

On Fri, 2023-03-10 at 09:53 +0100, Roberto Sassu wrote:
> From: Roberto Sassu <roberto.sassu at huawei.com>
> 
> Introduce LSM_ORDER_LAST, to satisfy the requirement of LSMs needing to be
> last, e.g. the 'integrity' LSM, without changing the kernel command line or
> configuration.
> 
> Also, set this order for the 'integrity' LSM. While not enforced, this is
> the only LSM expected to use it.
> 
> Similarly to LSM_ORDER_FIRST, LSMs with LSM_ORDER_LAST are always enabled
> and put at the end of the LSM list, if selected in the kernel
> configuration. Setting one of these orders alone, does not cause the LSMs
> to be selected and compiled built-in in the kernel.
> 
> Finally, for LSM_ORDER_MUTABLE LSMs, set the found variable to true if an
> LSM is found, regardless of its order. In this way, the kernel would not
> wrongly report that the LSM is not built-in in the kernel if its order is
> LSM_ORDER_LAST.
> 
> Fixes: 79f7865d844c ("LSM: Introduce "lsm=" for boottime LSM selection")
> Signed-off-by: Roberto Sassu <roberto.sassu at huawei.com>

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