Re: Common header for security blobs

Previous message: Stephen Smalley: "Re: quotactl hook"
In reply to: Greg KH: "Re: Common header for security blobs"
Next in thread: Stephen Smalley: "Re: Common header for security blobs"
Reply: Stephen Smalley: "Re: Common header for security blobs"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

chrisat_private

* Greg KH (gregat_private) wrote:

> I do recommend using a "magic value" as the first field of the security
> blob like Stephen mentioned.  That's just good defensive programming.
> 
> In short, if you want to do module stacking, you have to do all the
> heavy lifting yourself.

most important, the lsm interface (kernel hooks) don't know about module
stacking.  having a magic value is helpful, the magic value could easily
be the first value of

typedef struct security_blob {
       int      magic;
       void     *blob;
} security_t;

this does help define a standard without any central committe (like we
did with sys_security).  and doesn't force the kernel to be aware of
module stacking.

adding a list doesn't obviate the need for a multiplexor module

typedef struct security_blob {
       int              magic;
       struct list_head	s_list;
       void             *blob;
} security_t;

something needs to coallate the modules' decisions and generate an
aggreagrate result.

and if we add the magic number and list, we'd need to initialize them in a
generic fashion before calling the module's alloc_security() wouldn't we?

-chris

_______________________________________________
linux-security-module mailing list
linux-security-moduleat_private
http://mail.wirex.com/mailman/listinfo/linux-security-module