Re: [PATCH v2 0/6] LSM: Replace secctx/len pairs with lsm_context

From: Serge E. Hallyn
Date: Mon Oct 14 2024 - 17:36:09 EST


On Mon, Oct 14, 2024 at 04:29:37PM -0500, Serge E. Hallyn wrote:
> On Mon, Oct 14, 2024 at 08:14:44AM -0700, Casey Schaufler wrote:
> > LSM: Replace secctx/len pairs with lsm_context
> >
> > Several of the Linux Security Module (LSM) interfaces use a pair of
> > pointers for transmitting security context data and data length. The
> > data passed is refered to as a security context. While all existing
> > modules provide nul terminated strings, there is no requirement that
> > they to so. Hence, the length is necessary.
> >
> > Security contexts are provided by a number of interfaces. The interface
> > security_release_secctx() is used when the caller is finished with the
> > data. Each of the security modules that provide security contexts manages
> > them differently. This was safe in the past, because only one security
> > module that provides security contexts is allowed to be active. To allow
> > multiple active modules that use security contexts it is necessary to
> > identify which security module created a security context. Adding a third
> > pointer to the interfaces for the LSM identification is not appealing.
> >
> > A new structure, lsm_context, is created for use in these interfaces.
> > It includes three members: the data pointer, the data length and
> > the LSM ID of its creator. The interfaces that create contexts and
> > security_release_secctx() now use a pointer to an lsm_context instead
> > of a pointer pair.
> >
> > The changes are mostly mechanical, and some scaffolding is used within
> > the patch set to allow for smaller individual patches.
>
> Hey Casey,
>
> so this set is not bisectable. Applying just patch 1 will no compile, right?
> What is your plan for getting past that? Squash some or all of them into one?
> Or are you planning a wider reorg of the patches down the line, once the
> basics of the end result are agreed upon?

Sorry, I may have misread that. secids make my eyes glaze over.