[PATCH v9 13/25] security: Introduce file_release hook

[Casey Schaufler]

On 1/16/2024 12:47 AM, Roberto Sassu wrote:
> On Mon, 2024-01-15 at 19:15 +0000, Al Viro wrote:
>> On Mon, Jan 15, 2024 at 07:17:57PM +0100, Roberto Sassu wrote:
>>> From: Roberto Sassu <roberto.sassu at huawei.com>
>>>
>>> In preparation for moving IMA and EVM to the LSM infrastructure, introduce
>>> the file_release hook.
>>>
>>> IMA calculates at file close the new digest of the file content and writes
>>> it to security.ima, so that appraisal at next file access succeeds.
>>>
>>> An LSM could implement an exclusive access scheme for files, only allowing
>>> access to files that have no references.
>> Elaborate that last part, please.
> Apologies, I didn't understand that either. Casey?

Just a hypothetical notion that if an LSM wanted to implement an
exclusive access scheme it might find the proposed hook helpful.
I don't have any plan to create such a scheme, nor do I think that
a file_release hook would be the only thing you'd need.

>
> Thanks
>
> Roberto
>