Messages in this thread | | | From | David Howells <> | Subject | Re: [PATCH 08/28] SECURITY: Allow kernel services to override LSM settings for task actions [try #2] | Date | Wed, 12 Dec 2007 22:29:55 +0000 |
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Casey Schaufler <casey@schaufler-ca.com> wrote:
> Yes, but we're talking about writing the configuration information > to the kernel, not actually making any access checks with it. I > think. What I think we're talking about (and please correct me David > if I've stepped into the wrong theatre) is getting the magic > secctx that cachefiles will use instead of the secctx that the task > would have otherwise. I don't think we're talking about recomputing > it on every access, I think David is looking for the blunderbuss > secctx that he can use any time he needs one.
Indeed.
The way I do it is:
(1) The daemon opens /dev/cachefiles to being an instance of a cache.
(2) The daemon negotiates a security context for the module to use.
(3) The security context is place in a task_security structure.
(4) This task_security struct is attached temporarily to task->act_as each time any task attempts to access the cache through the module.
(5) The task_security struct is discarded when the file descriptor that was created in (1) is closed and the cache is withdrawn at the same time.
David
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