The current state of Security manager's code is kind of a mess. Mainly, there's code scattered around places where they shouldn't belong and token implementation (token.c) is already of a bloat in itself as it is. The file has over 6k lines and it's subject to grow exponentially with improvements, features, whatever that is.
With that being said, the token implementation code in the kernel will be split accordingly and rest of the code moved to appropriate places. The new layout will look as follows (excluding the already existing files):
- client.c (Client security implementation code)
- objtype.c (Object type list implementation code -- more code related to object types will be put here when I'm going to implement object type access checks in the future)
- subject.c (Subject security context support)
The token implementation in the kernel will be split in 4 distinct files as shown:
- token.c (Base token support routines)
- tokenlif.c (Life management of a token object -- that is Duplication, Creation and Filtering)
- tokencls.c (Token Query/Set Information Classes support)
- tokenadj.c (Token privileges/groups adjusting support)
In addition to that, tidy up the internal header and reorganize it as well.
This function will be used to retrieve a security identifier from a valid access control entry in the kernel. Mostly and exclusively used within access checks related code and such.
This reverts 8479509 commit which pretty much does nothing at all (the captured pointer is NULL within the stack of the function has no effect outside of the function). My mistake, sorry.
Whenever a captured security property such as privilege or SID is released, we must not have such captured property point at random address in memory but rather we must assign it as NULL after it's been freed from pool memory. This avoids potential double-after-free situations where we might release a buffer twice.
This is exactly the case with token filtering.
SIDs are variadic by nature which means their lengths can vary in a given amount of time and certain factors that allow for this happen. This also especially can lead to issues when capturing SIDs and attributes because SeCaptureSidAndAttributesArray might end up overwriting the buffer during the time it's been called.
Therefore when we're copying the SIDs, validate their lengths. In addition to that, update the documentation header accordingly and add some debug prints in code.
- Change INIT_FUNCTION and INIT_SECTION to CODE_SEG("INIT") and DATA_SEG("INIT") respectively
- Remove INIT_FUNCTION from function prototypes
- Remove alloc_text pragma calls as they are not needed anymore
